proper constant handling

rc nightmare...

Cargo.lock

@@ -288,15 +288,6 @@ dependencies = [
  "proc-macro-hack",
 ]
 
-[[package]]
-name = "indoc"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5a75aeaaef0ce18b58056d306c27b07436fbb34b8816c53094b76dd81803136"
-dependencies = [
- "unindent",
-]
-
 [[package]]
 name = "indoc-impl"
 version = "0.3.6"
@@ -458,12 +449,10 @@ checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 name = "nac3core"
 version = "0.1.0"
 dependencies = [
- "indoc 1.0.3",
  "inkwell",
  "num-bigint",
  "num-traits",
  "rustpython-parser",
- "thiserror",
 ]
 
 [[package]]
@@ -624,7 +613,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bf6bbbe8f70d179260b3728e5d04eb012f4f0c7988e58c11433dd689cecaa72e"
 dependencies = [
  "ctor",
- "indoc 0.3.6",
+ "indoc",
  "inventory",
  "libc",
  "parking_lot",
@@ -841,26 +830,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "thiserror"
-version = "1.0.23"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76cc616c6abf8c8928e2fdcc0dbfab37175edd8fb49a4641066ad1364fdab146"
-dependencies = [
- "thiserror-impl",
-]
-
-[[package]]
-name = "thiserror-impl"
-version = "1.0.23"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9be73a2caec27583d0046ef3796c3794f868a5bc813db689eed00c7631275cd1"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "thread_local"
 version = "1.0.1"

nac3core/Cargo.toml

@@ -7,10 +7,5 @@ edition = "2018"
 [dependencies]
 num-bigint = "0.3"
 num-traits = "0.2"
-thiserror = "1.0"
 inkwell = { git = "https://github.com/TheDan64/inkwell", branch = "master", features = ["llvm10-0"] }
 rustpython-parser = { git = "https://github.com/RustPython/RustPython", branch = "master" }
-
-[dev-dependencies]
-indoc = "1.0"
-

nac3core/src/expression.rs

@@ -0,0 +1,377 @@
+use crate::inference::resolve_call;
+use crate::operators::*;
+use crate::primitives::*;
+use crate::typedef::{GlobalContext, Type, Type::*};
+use rustpython_parser::ast::{
+    Comparison, Comprehension, ComprehensionKind, Expression, ExpressionType, Operator,
+    UnaryOperator,
+};
+use std::collections::HashMap;
+use std::convert::TryInto;
+use std::rc::Rc;
+
+type SymTable<'a> = HashMap<&'a str, Rc<Type>>;
+type ParserResult = Result<Option<Rc<Type>>, String>;
+
+pub fn parse_expr(ctx: &GlobalContext, sym_table: &SymTable, expr: &Expression) -> ParserResult {
+    match &expr.node {
+        ExpressionType::Number { value } => parse_constant(ctx, sym_table, value),
+        ExpressionType::Identifier { name } => parse_identifier(ctx, sym_table, name),
+        ExpressionType::List { elements } => parse_list(ctx, sym_table, elements),
+        ExpressionType::Tuple { elements } => parse_tuple(ctx, sym_table, elements),
+        ExpressionType::Attribute { value, name } => parse_attribute(ctx, sym_table, value, name),
+        ExpressionType::BoolOp { values, .. } => parse_bool_ops(ctx, sym_table, values),
+        ExpressionType::Binop { a, b, op } => parse_bin_ops(ctx, sym_table, op, a, b),
+        ExpressionType::Unop { op, a } => parse_unary_ops(ctx, sym_table, op, a),
+        ExpressionType::Compare { vals, ops } => parse_compare(ctx, sym_table, vals, ops),
+        ExpressionType::Call {
+            args,
+            function,
+            keywords,
+        } => {
+            if keywords.len() > 0 {
+                Err("keyword is not supported".into())
+            } else {
+                parse_call(ctx, sym_table, &args, &function)
+            }
+        }
+        ExpressionType::Subscript { a, b } => parse_subscript(ctx, sym_table, a, b),
+        ExpressionType::IfExpression { test, body, orelse } => {
+            parse_if_expr(ctx, sym_table, &test, &body, orelse)
+        }
+        ExpressionType::Comprehension { kind, generators } => match kind.as_ref() {
+            ComprehensionKind::List { element } => {
+                if generators.len() == 1 {
+                    parse_list_comprehension(ctx, sym_table, element, &generators[0])
+                } else {
+                    Err("only 1 generator statement is supported".into())
+                }
+            }
+            _ => Err("only list comprehension is supported".into()),
+        },
+        ExpressionType::True | ExpressionType::False => Ok(Some(PrimitiveType(BOOL_TYPE).into())),
+        _ => Err("not supported".into()),
+    }
+}
+
+fn parse_constant(
+    _: &GlobalContext,
+    _: &SymTable,
+    value: &rustpython_parser::ast::Number,
+) -> ParserResult {
+    use rustpython_parser::ast::Number;
+    match value {
+        Number::Integer { value } => {
+            let int32: Result<i32, _> = value.try_into();
+            if int32.is_ok() {
+                Ok(Some(PrimitiveType(INT32_TYPE).into()))
+            } else {
+                let int64: Result<i64, _> = value.try_into();
+                if int64.is_ok() {
+                    Ok(Some(PrimitiveType(INT64_TYPE).into()))
+                } else {
+                    Err("integer out of range".into())
+                }
+            }
+        }
+        Number::Float { .. } => Ok(Some(PrimitiveType(FLOAT_TYPE).into())),
+        _ => Err("not supported".into()),
+    }
+}
+
+fn parse_identifier(_: &GlobalContext, sym_table: &SymTable, name: &str) -> ParserResult {
+    match sym_table.get(name) {
+        Some(v) => Ok(Some(v.clone())),
+        None => Err("unbounded variable".into()),
+    }
+}
+
+fn parse_list(ctx: &GlobalContext, sym_table: &SymTable, elements: &[Expression]) -> ParserResult {
+    if elements.len() == 0 {
+        return Ok(Some(ParametricType(LIST_TYPE, vec![BotType.into()]).into()));
+    }
+
+    let mut types = elements.iter().map(|v| parse_expr(&ctx, sym_table, v));
+
+    let head = types.next().unwrap()?;
+    if head.is_none() {
+        return Err("list elements must have some type".into());
+    }
+    for v in types {
+        if v? != head {
+            return Err("inhomogeneous list is not allowed".into());
+        }
+    }
+    Ok(Some(ParametricType(LIST_TYPE, vec![head.unwrap()]).into()))
+}
+
+fn parse_tuple(ctx: &GlobalContext, sym_table: &SymTable, elements: &[Expression]) -> ParserResult {
+    let types: Result<Option<Vec<_>>, String> = elements
+        .iter()
+        .map(|v| parse_expr(&ctx, sym_table, v))
+        .collect();
+    if let Some(t) = types? {
+        Ok(Some(ParametricType(TUPLE_TYPE, t).into()))
+    } else {
+        Err("tuple elements must have some type".into())
+    }
+}
+
+fn parse_attribute(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    value: &Expression,
+    name: &String,
+) -> ParserResult {
+    let value = parse_expr(ctx, sym_table, value)?.ok_or("no value".to_string())?;
+    if let TypeVariable(id) = value.as_ref() {
+        let v = ctx.get_variable(*id);
+        if v.bound.len() == 0 {
+            return Err("no fields on unbounded type variable".into());
+        }
+        let ty = v.bound[0]
+            .get_base(ctx)
+            .and_then(|v| v.fields.get(name.as_str()));
+        if ty.is_none() {
+            return Err("unknown field".into());
+        }
+        for x in v.bound[1..].iter() {
+            let ty1 = x.get_base(ctx).and_then(|v| v.fields.get(name.as_str()));
+            if ty1 != ty {
+                return Err("unknown field (type mismatch between variants)".into());
+            }
+        }
+        return Ok(Some(ty.unwrap().clone()));
+    }
+
+    match value.get_base(ctx) {
+        Some(b) => match b.fields.get(name.as_str()) {
+            Some(t) => Ok(Some(t.clone())),
+            None => Err("no such field".into()),
+        },
+        None => Err("this object has no fields".into()),
+    }
+}
+
+fn parse_bool_ops(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    values: &[Expression],
+) -> ParserResult {
+    assert_eq!(values.len(), 2);
+    let left = parse_expr(ctx, sym_table, &values[0])?.ok_or("no value".to_string())?;
+    let right = parse_expr(ctx, sym_table, &values[1])?.ok_or("no value".to_string())?;
+
+    let b = PrimitiveType(BOOL_TYPE);
+    if left.as_ref() == &b && right.as_ref() == &b {
+        Ok(Some(b.into()))
+    } else {
+        Err("bool operands must be bool".into())
+    }
+}
+
+fn parse_bin_ops(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    op: &Operator,
+    left: &Expression,
+    right: &Expression,
+) -> ParserResult {
+    let left = parse_expr(ctx, sym_table, left)?.ok_or("no value".to_string())?;
+    let right = parse_expr(ctx, sym_table, right)?.ok_or("no value".to_string())?;
+    let fun = binop_name(op);
+    resolve_call(ctx, Some(left), fun, &[right])
+}
+
+fn parse_unary_ops(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    op: &UnaryOperator,
+    obj: &Expression,
+) -> ParserResult {
+    let ty = parse_expr(ctx, sym_table, obj)?.ok_or("no value".to_string())?;
+    if let UnaryOperator::Not = op {
+        if ty.as_ref() == &PrimitiveType(BOOL_TYPE) {
+            Ok(Some(ty))
+        } else {
+            Err("logical not must be applied to bool".into())
+        }
+    } else {
+        resolve_call(ctx, Some(ty), unaryop_name(op), &[])
+    }
+}
+
+fn parse_compare(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    vals: &[Expression],
+    ops: &[Comparison],
+) -> ParserResult {
+    let types: Result<Option<Vec<_>>, _> =
+        vals.iter().map(|v| parse_expr(ctx, sym_table, v)).collect();
+    let types = types?;
+    if types.is_none() {
+        return Err("comparison operands must have type".into());
+    }
+    let types = types.unwrap();
+    let boolean = PrimitiveType(BOOL_TYPE);
+    let left = &types[..types.len() - 1];
+    let right = &types[1..];
+
+    for ((a, b), op) in left.iter().zip(right.iter()).zip(ops.iter()) {
+        let fun = comparison_name(op).ok_or("unsupported comparison".to_string())?;
+        let ty = resolve_call(ctx, Some(a.clone()), fun, &[b.clone()])?;
+        if ty.is_none() || ty.unwrap().as_ref() != &boolean {
+            return Err("comparison result must be boolean".into());
+        }
+    }
+    Ok(Some(boolean.into()))
+}
+
+fn parse_call(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    args: &[Expression],
+    function: &Expression,
+) -> ParserResult {
+    let types: Result<Option<Vec<_>>, _> =
+        args.iter().map(|v| parse_expr(ctx, sym_table, v)).collect();
+    let types = types?;
+    if types.is_none() {
+        return Err("function params must have type".into());
+    }
+
+    let (obj, fun) = match &function.node {
+        ExpressionType::Identifier { name } => (None, name),
+        ExpressionType::Attribute { value, name } => (
+            Some(parse_expr(ctx, sym_table, &value)?.ok_or("no value".to_string())?),
+            name,
+        ),
+        _ => return Err("not supported".into()),
+    };
+    resolve_call(ctx, obj, fun.as_str(), &types.unwrap())
+}
+
+fn parse_subscript(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    a: &Expression,
+    b: &Expression,
+) -> ParserResult {
+    let a = parse_expr(ctx, sym_table, a)?.ok_or("no value".to_string())?;
+    let t = if let ParametricType(LIST_TYPE, ls) = a.as_ref() {
+        ls[0].clone()
+    } else {
+        return Err("subscript is not supported for types other than list".into());
+    };
+
+    match &b.node {
+        ExpressionType::Slice { elements } => {
+            let types: Result<Option<Vec<_>>, _> = elements
+                .iter()
+                .map(|v| parse_expr(ctx, sym_table, v))
+                .collect();
+            let types = types?.ok_or("slice must have type".to_string())?;
+            let int32 = PrimitiveType(INT32_TYPE);
+            if types.iter().all(|v| v.as_ref() == &int32) {
+                Ok(Some(a))
+            } else {
+                Err("slice must be int32 type".into())
+            }
+        }
+        _ => {
+            let b = parse_expr(ctx, sym_table, b)?.ok_or("no value".to_string())?;
+            if b.as_ref() == &PrimitiveType(INT32_TYPE) {
+                Ok(Some(t))
+            } else {
+                Err("index must be either slice or int32".into())
+            }
+        }
+    }
+}
+
+fn parse_if_expr(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    test: &Expression,
+    body: &Expression,
+    orelse: &Expression,
+) -> ParserResult {
+    let test = parse_expr(ctx, sym_table, test)?.ok_or("no value".to_string())?;
+    if test.as_ref() != &PrimitiveType(BOOL_TYPE) {
+        return Err("test should be bool".into());
+    }
+
+    let body = parse_expr(ctx, sym_table, body)?.ok_or("no value".to_string())?;
+    let orelse = parse_expr(ctx, sym_table, orelse)?.ok_or("no value".to_string())?;
+    if body.as_ref() == orelse.as_ref() {
+        Ok(Some(body))
+    } else {
+        Err("divergent type".into())
+    }
+}
+
+fn parse_simple_binding<'a: 'b, 'b>(
+    sym_table: &mut SymTable<'b>,
+    name: &'a Expression,
+    ty: Rc<Type>,
+) -> Result<(), String> {
+    match &name.node {
+        ExpressionType::Identifier { name } => {
+            if name == "_" {
+                Ok(())
+            } else if sym_table.get(name.as_str()).is_some() {
+                Err("duplicated naming".into())
+            } else {
+                sym_table.insert(name.as_str(), ty);
+                Ok(())
+            }
+        }
+        ExpressionType::Tuple { elements } => {
+            if let ParametricType(TUPLE_TYPE, ls) = ty.as_ref() {
+                if elements.len() == ls.len() {
+                    for (a, b) in elements.iter().zip(ls.iter()) {
+                        parse_simple_binding(sym_table, a, b.clone())?;
+                    }
+                    Ok(())
+                } else {
+                    Err("different length".into())
+                }
+            } else {
+                Err("not supported".into())
+            }
+        }
+        _ => Err("not supported".into()),
+    }
+}
+
+fn parse_list_comprehension(
+    ctx: &GlobalContext,
+    sym_table: &SymTable,
+    element: &Expression,
+    comprehension: &Comprehension,
+) -> ParserResult {
+    if comprehension.is_async {
+        return Err("async is not supported".into());
+    }
+
+    // TODO: it may be more efficient to use multi-level table
+    // but it would better done in a whole program level
+    let iter = parse_expr(ctx, sym_table, &comprehension.iter)?.ok_or("no value".to_string())?;
+    if let ParametricType(LIST_TYPE, ls) = iter.as_ref() {
+        let mut local_sym = sym_table.clone();
+        parse_simple_binding(&mut local_sym, &comprehension.target, ls[0].clone())?;
+
+        let boolean = PrimitiveType(BOOL_TYPE);
+        for test in comprehension.ifs.iter() {
+            let result =
+                parse_expr(ctx, &local_sym, test)?.ok_or("no value in test".to_string())?;
+            if result.as_ref() != &boolean {
+                return Err("test must be bool".into());
+            }
+        }
+        parse_expr(ctx, &local_sym, element)
+    } else {
+        Err("iteration is supported for list only".into())
+    }
+}

nac3core/src/inference.rs

@@ -1,29 +1,15 @@
-use super::context::InferenceContext;
-use super::typedef::{TypeEnum::*, *};
+use super::typedef::{Type::*, *};
 use std::collections::HashMap;
-use thiserror::Error;
-
-#[derive(Error, Debug)]
-enum SubstError {
-    #[error("different type variables after substitution")]
-    DifferentSubstVar(VariableId, VariableId),
-    #[error("cannot substitute unbounded type variable into bounded one")]
-    UnboundedTypeVar(VariableId, VariableId),
-    #[error("incompatible bound for type variables")]
-    IncompatibleBound(VariableId, VariableId),
-    #[error("only subtype of virtual class can be substituted into virtual class type")]
-    NotVirtualClassSubtype(Type, ClassId),
-    #[error("different types")]
-    DifferentTypes(Type, Type),
-}
+use std::rc::Rc;
 
 fn find_subst(
-    ctx: &InferenceContext,
-    valuation: &Option<(VariableId, Type)>,
-    sub: &mut HashMap<VariableId, Type>,
-    mut a: Type,
-    mut b: Type,
-) -> Result<(), SubstError> {
+    ctx: &GlobalContext,
+    valuation: &Option<(VariableId, Rc<Type>)>,
+    sub: &mut HashMap<VariableId, Rc<Type>>,
+    mut a: Rc<Type>,
+    mut b: Rc<Type>,
+) -> Result<(), String> {
+    // TODO: fix error messages later
     if let TypeVariable(id) = a.as_ref() {
         if let Some((assumption_id, t)) = valuation {
             if assumption_id == id {
@@ -47,43 +33,43 @@ fn find_subst(
                 return if id_a == id_b {
                     Ok(())
                 } else {
-                    Err(SubstError::DifferentSubstVar(*id_a, *id_b))
+                    Err("different variables".to_string())
                 };
             }
-            let v_a = ctx.get_variable_def(*id_a);
-            let v_b = ctx.get_variable_def(*id_b);
-            if !v_b.bound.is_empty() {
-                if v_a.bound.is_empty() {
-                    return Err(SubstError::UnboundedTypeVar(*id_a, *id_b));
+            let v_a = ctx.get_variable(*id_a);
+            let v_b = ctx.get_variable(*id_b);
+            if v_b.bound.len() > 0 {
+                if v_a.bound.len() == 0 {
+                    return Err("unbounded a".to_string());
                 } else {
                     let diff: Vec<_> = v_a
                         .bound
                         .iter()
                         .filter(|x| !v_b.bound.contains(x))
                         .collect();
-                    if !diff.is_empty() {
-                        return Err(SubstError::IncompatibleBound(*id_a, *id_b));
+                    if diff.len() > 0 {
+                        return Err("different domain".to_string());
                     }
                 }
             }
-            sub.insert(*id_b, a.clone());
+            sub.insert(*id_b, a.clone().into());
             Ok(())
         }
         (TypeVariable(id_a), _) => {
-            let v_a = ctx.get_variable_def(*id_a);
+            let v_a = ctx.get_variable(*id_a);
             if v_a.bound.len() == 1 && v_a.bound[0].as_ref() == b.as_ref() {
                 Ok(())
             } else {
-                Err(SubstError::DifferentTypes(a.clone(), b.clone()))
+                Err("different domain".to_string())
             }
         }
         (_, TypeVariable(id_b)) => {
-            let v_b = ctx.get_variable_def(*id_b);
-            if v_b.bound.is_empty() || v_b.bound.contains(&a) {
-                sub.insert(*id_b, a.clone());
+            let v_b = ctx.get_variable(*id_b);
+            if v_b.bound.len() == 0 || v_b.bound.contains(&a) {
+                sub.insert(*id_b, a.clone().into());
                 Ok(())
             } else {
-                Err(SubstError::DifferentTypes(a.clone(), b.clone()))
+                Err("different domain".to_string())
             }
         }
         (_, VirtualClassType(id_b)) => {
@@ -96,21 +82,21 @@ fn find_subst(
                     parents = [*id_a].to_vec();
                 }
                 _ => {
-                    return Err(SubstError::NotVirtualClassSubtype(a.clone(), *id_b));
+                    return Err("cannot substitute non-class type into virtual class".to_string());
                 }
             };
             while !parents.is_empty() {
                 if *id_b == parents[0] {
                     return Ok(());
                 }
-                let c = ctx.get_class_def(parents.remove(0));
+                let c = ctx.get_class(parents.remove(0));
                 parents.extend_from_slice(&c.parents);
             }
-            Err(SubstError::NotVirtualClassSubtype(a.clone(), *id_b))
+            Err("not subtype".to_string())
         }
         (ParametricType(id_a, param_a), ParametricType(id_b, param_b)) => {
             if id_a != id_b || param_a.len() != param_b.len() {
-                Err(SubstError::DifferentTypes(a.clone(), b.clone()))
+                Err("different parametric types".to_string())
             } else {
                 for (x, y) in param_a.iter().zip(param_b.iter()) {
                     find_subst(ctx, valuation, sub, x.clone(), y.clone())?;
@@ -122,30 +108,30 @@ fn find_subst(
             if a == b {
                 Ok(())
             } else {
-                Err(SubstError::DifferentTypes(a.clone(), b.clone()))
+                Err("not equal".to_string())
             }
         }
     }
 }
 
 fn resolve_call_rec(
-    ctx: &InferenceContext,
-    valuation: &Option<(VariableId, Type)>,
-    obj: Option<Type>,
+    ctx: &GlobalContext,
+    valuation: &Option<(VariableId, Rc<Type>)>,
+    obj: Option<Rc<Type>>,
     func: &str,
-    args: &[Type],
-) -> Result<Option<Type>, String> {
+    args: &[Rc<Type>],
+) -> Result<Option<Rc<Type>>, String> {
     let mut subst = obj
         .as_ref()
         .map(|v| v.get_subst(ctx))
-        .unwrap_or_else(HashMap::new);
+        .unwrap_or(HashMap::new());
 
     let fun = match &obj {
         Some(obj) => {
             let base = match obj.as_ref() {
                 TypeVariable(id) => {
-                    let v = ctx.get_variable_def(*id);
-                    if v.bound.is_empty() {
+                    let v = ctx.get_variable(*id);
+                    if v.bound.len() == 0 {
                         return Err("unbounded type var".to_string());
                     }
                     let results: Result<Vec<_>, String> = v
@@ -167,7 +153,7 @@ fn resolve_call_rec(
                     }
                     let mut results = results.iter().zip(v.bound.iter()).map(|(r, ins)| {
                         r.as_ref()
-                            .map(|v| v.inv_subst(&[(ins.clone(), obj.clone())]))
+                            .map(|v| v.inv_subst(&[(ins.clone(), obj.clone().into())]))
                     });
                     let first = results.next().unwrap();
                     if results.all(|v| v == first) {
@@ -176,22 +162,22 @@ fn resolve_call_rec(
                         return Err("divergent type after substitution".to_string());
                     }
                 }
-                PrimitiveType(id) => &ctx.get_primitive_def(*id),
-                ClassType(id) | VirtualClassType(id) => &ctx.get_class_def(*id).base,
-                ParametricType(id, _) => &ctx.get_parametric_def(*id).base,
+                PrimitiveType(id) => &ctx.get_primitive(*id),
+                ClassType(id) | VirtualClassType(id) => &ctx.get_class(*id).base,
+                ParametricType(id, _) => &ctx.get_parametric(*id).base,
                 _ => return Err("not supported".to_string()),
             };
             base.methods.get(func)
         }
-        None => ctx.get_fn_def(func),
+        None => ctx.get_fn(func),
     }
-    .ok_or_else(|| "no such function".to_string())?;
+    .ok_or("no such function".to_string())?;
 
     if args.len() != fun.args.len() {
         return Err("incorrect parameter number".to_string());
     }
     for (a, b) in args.iter().zip(fun.args.iter()) {
-        find_subst(ctx, valuation, &mut subst, a.clone(), b.clone()).map_err(|v| v.to_string())?;
+        find_subst(ctx, valuation, &mut subst, a.clone(), b.clone())?;
     }
     let result = fun.result.as_ref().map(|v| v.subst(&subst));
     Ok(result.map(|result| {
@@ -204,114 +190,109 @@ fn resolve_call_rec(
 }
 
 pub fn resolve_call(
-    ctx: &InferenceContext,
-    obj: Option<Type>,
+    ctx: &GlobalContext,
+    obj: Option<Rc<Type>>,
     func: &str,
-    args: &[Type],
-) -> Result<Option<Type>, String> {
+    args: &[Rc<Type>],
+) -> Result<Option<Rc<Type>>, String> {
     resolve_call_rec(ctx, &None, obj, func, args)
 }
 
 #[cfg(test)]
 mod tests {
-    use super::{
-        super::{context::*, primitives::*},
-        *,
-    };
-    use std::matches;
-    use std::rc::Rc;
-
-    fn get_inference_context(ctx: TopLevelContext) -> InferenceContext {
-        InferenceContext::new(ctx, Box::new(|_| Err("unbounded identifier".into())))
-    }
+    use super::*;
+    use crate::primitives::*;
 
     #[test]
     fn test_simple_generic() {
         let mut ctx = basic_ctx();
+
+        assert_eq!(
+            resolve_call(&ctx, None, "int32", &[PrimitiveType(FLOAT_TYPE).into()]),
+            Ok(Some(PrimitiveType(INT32_TYPE).into()))
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "int32", &[PrimitiveType(INT32_TYPE).into()],),
+            Ok(Some(PrimitiveType(INT32_TYPE).into()))
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "float", &[PrimitiveType(INT32_TYPE).into()]),
+            Ok(Some(PrimitiveType(FLOAT_TYPE).into()))
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "float", &[PrimitiveType(BOOL_TYPE).into()]),
+            Err("different domain".to_string())
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "float", &[]),
+            Err("incorrect parameter number".to_string())
+        );
+
         let v1 = ctx.add_variable(VarDef {
             name: "V1",
-            bound: vec![ctx.get_primitive(INT32_TYPE), ctx.get_primitive(FLOAT_TYPE)],
+            bound: vec![
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
         });
-        let v1 = ctx.get_variable(v1);
+
+        assert_eq!(
+            resolve_call(&ctx, None, "float", &[TypeVariable(v1).into()]),
+            Ok(Some(PrimitiveType(FLOAT_TYPE).into()))
+        );
+
         let v2 = ctx.add_variable(VarDef {
             name: "V2",
             bound: vec![
-                ctx.get_primitive(BOOL_TYPE),
-                ctx.get_primitive(INT32_TYPE),
-                ctx.get_primitive(FLOAT_TYPE),
+                PrimitiveType(BOOL_TYPE).into(),
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
             ],
         });
-        let v2 = ctx.get_variable(v2);
-        let ctx = get_inference_context(ctx);
 
         assert_eq!(
-            resolve_call(&ctx, None, "int32", &[ctx.get_primitive(FLOAT_TYPE)]),
-            Ok(Some(ctx.get_primitive(INT32_TYPE)))
+            resolve_call(&ctx, None, "float", &[TypeVariable(v2).into()]),
+            Err("different domain".to_string())
         );
-
-        assert_eq!(
-            resolve_call(&ctx, None, "int32", &[ctx.get_primitive(INT32_TYPE)],),
-            Ok(Some(ctx.get_primitive(INT32_TYPE)))
-        );
-
-        assert_eq!(
-            resolve_call(&ctx, None, "float", &[ctx.get_primitive(INT32_TYPE)]),
-            Ok(Some(ctx.get_primitive(FLOAT_TYPE)))
-        );
-
-        assert!(matches!(
-            resolve_call(&ctx, None, "float", &[ctx.get_primitive(BOOL_TYPE)]),
-            Err(..)
-        ));
-
-        assert!(matches!(
-            resolve_call(&ctx, None, "float", &[]),
-            Err(..)
-        ));
-
-        assert_eq!(
-            resolve_call(&ctx, None, "float", &[v1]),
-            Ok(Some(ctx.get_primitive(FLOAT_TYPE)))
-        );
-
-        assert!(matches!(
-            resolve_call(&ctx, None, "float", &[v2]),
-            Err(..)
-        ));
     }
 
     #[test]
     fn test_methods() {
         let mut ctx = basic_ctx();
 
-        let v0 = ctx.add_variable(VarDef {
+        let v0 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V0",
             bound: vec![],
-        });
-        let v0 = ctx.get_variable(v0);
-        let v1 = ctx.add_variable(VarDef {
+        })));
+        let v1 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V1",
-            bound: vec![ctx.get_primitive(INT32_TYPE), ctx.get_primitive(FLOAT_TYPE)],
-        });
-        let v1 = ctx.get_variable(v1);
-        let v2 = ctx.add_variable(VarDef {
+            bound: vec![
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
+        })));
+        let v2 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V2",
-            bound: vec![ctx.get_primitive(INT32_TYPE), ctx.get_primitive(FLOAT_TYPE)],
-        });
-        let v2 = ctx.get_variable(v2);
-        let v3 = ctx.add_variable(VarDef {
+            bound: vec![
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
+        })));
+        let v3 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V3",
             bound: vec![
-                ctx.get_primitive(BOOL_TYPE),
-                ctx.get_primitive(INT32_TYPE),
-                ctx.get_primitive(FLOAT_TYPE),
+                PrimitiveType(BOOL_TYPE).into(),
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
             ],
-        });
-        let v3 = ctx.get_variable(v3);
+        })));
 
-        let int32 = ctx.get_primitive(INT32_TYPE);
-        let int64 = ctx.get_primitive(INT64_TYPE);
-        let ctx = get_inference_context(ctx);
+        let int32 = Rc::new(PrimitiveType(INT32_TYPE));
+        let int64 = Rc::new(PrimitiveType(INT64_TYPE));
 
         // simple cases
         assert_eq!(
@@ -324,65 +305,61 @@ mod tests {
             Ok(Some(int64.clone()))
         );
 
-        assert!(matches!(
-            resolve_call(&ctx, Some(int32), "__add__", &[int64]),
-            Err(..)
-        ));
+        assert_eq!(
+            resolve_call(&ctx, Some(int32.clone()), "__add__", &[int64.clone()]),
+            Err("not equal".to_string())
+        );
 
         // with type variables
         assert_eq!(
             resolve_call(&ctx, Some(v1.clone()), "__add__", &[v1.clone()]),
             Ok(Some(v1.clone()))
         );
-        assert!(matches!(
+        assert_eq!(
             resolve_call(&ctx, Some(v0.clone()), "__add__", &[v2.clone()]),
-            Err(..)
-        ));
-        assert!(matches!(
-            resolve_call(&ctx, Some(v1.clone()), "__add__", &[v0]),
-            Err(..)
-        ));
-        assert!(matches!(
-            resolve_call(&ctx, Some(v1.clone()), "__add__", &[v2]),
-            Err(..)
-        ));
-        assert!(matches!(
+            Err("unbounded type var".to_string())
+        );
+        assert_eq!(
+            resolve_call(&ctx, Some(v1.clone()), "__add__", &[v0.clone()]),
+            Err("different domain".to_string())
+        );
+        assert_eq!(
+            resolve_call(&ctx, Some(v1.clone()), "__add__", &[v2.clone()]),
+            Err("different domain".to_string())
+        );
+        assert_eq!(
             resolve_call(&ctx, Some(v1.clone()), "__add__", &[v3.clone()]),
-            Err(..)
-        ));
-        assert!(matches!(
-            resolve_call(&ctx, Some(v3.clone()), "__add__", &[v1]),
-            Err(..)
-        ));
-        assert!(matches!(
-            resolve_call(&ctx, Some(v3.clone()), "__add__", &[v3]),
-            Err(..)
-        ));
+            Err("different domain".to_string())
+        );
+        assert_eq!(
+            resolve_call(&ctx, Some(v3.clone()), "__add__", &[v1.clone()]),
+            Err("no such function".to_string())
+        );
+        assert_eq!(
+            resolve_call(&ctx, Some(v3.clone()), "__add__", &[v3.clone()]),
+            Err("no such function".to_string())
+        );
     }
 
     #[test]
     fn test_multi_generic() {
         let mut ctx = basic_ctx();
-        let v0 = ctx.add_variable(VarDef {
+        let v0 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V0",
             bound: vec![],
-        });
-        let v0 = ctx.get_variable(v0);
-        let v1 = ctx.add_variable(VarDef {
+        })));
+        let v1 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V1",
             bound: vec![],
-        });
-        let v1 = ctx.get_variable(v1);
-        let v2 = ctx.add_variable(VarDef {
+        })));
+        let v2 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V2",
             bound: vec![],
-        });
-        let v2 = ctx.get_variable(v2);
-        let v3 = ctx.add_variable(VarDef {
+        })));
+        let v3 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V3",
             bound: vec![],
-        });
-        let v3 = ctx.get_variable(v3);
+        })));
 
         ctx.add_fn(
             "foo",
@@ -395,11 +372,12 @@ mod tests {
         ctx.add_fn(
             "foo1",
             FnDef {
-                args: vec![ParametricType(TUPLE_TYPE, vec![v0.clone(), v0.clone(), v1]).into()],
-                result: Some(v0),
+                args: vec![
+                    ParametricType(TUPLE_TYPE, vec![v0.clone(), v0.clone(), v1.clone()]).into(),
+                ],
+                result: Some(v0.clone()),
             },
         );
-        let ctx = get_inference_context(ctx);
 
         assert_eq!(
             resolve_call(&ctx, None, "foo", &[v2.clone(), v2.clone(), v2.clone()]),
@@ -409,10 +387,10 @@ mod tests {
             resolve_call(&ctx, None, "foo", &[v2.clone(), v2.clone(), v3.clone()]),
             Ok(Some(v2.clone()))
         );
-        assert!(matches!(
+        assert_eq!(
             resolve_call(&ctx, None, "foo", &[v2.clone(), v3.clone(), v3.clone()]),
-            Err(..)
-        ));
+            Err("different variables".to_string())
+        );
 
         assert_eq!(
             resolve_call(
@@ -432,22 +410,22 @@ mod tests {
             ),
             Ok(Some(v2.clone()))
         );
-        assert!(matches!(
+        assert_eq!(
             resolve_call(
                 &ctx,
                 None,
                 "foo1",
-                &[ParametricType(TUPLE_TYPE, vec![v2, v3.clone(), v3]).into()]
+                &[ParametricType(TUPLE_TYPE, vec![v2.clone(), v3.clone(), v3.clone()]).into()]
             ),
-            Err(..)
-        ));
+            Err("different variables".to_string())
+        );
     }
 
     #[test]
     fn test_class_generics() {
         let mut ctx = basic_ctx();
 
-        let list = ctx.get_parametric_def_mut(LIST_TYPE);
+        let list = ctx.get_parametric_mut(LIST_TYPE);
         let t = Rc::new(TypeVariable(list.params[0]));
         list.base.methods.insert(
             "head",
@@ -459,22 +437,19 @@ mod tests {
         list.base.methods.insert(
             "append",
             FnDef {
-                args: vec![t],
+                args: vec![t.clone()],
                 result: None,
             },
         );
 
-        let v0 = ctx.add_variable(VarDef {
+        let v0 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V0",
             bound: vec![],
-        });
-        let v0 = ctx.get_variable(v0);
-        let v1 = ctx.add_variable(VarDef {
+        })));
+        let v1 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
             name: "V1",
             bound: vec![],
-        });
-        let v1 = ctx.get_variable(v1);
-        let ctx = get_inference_context(ctx);
+        })));
 
         assert_eq!(
             resolve_call(
@@ -494,15 +469,15 @@ mod tests {
             ),
             Ok(None)
         );
-        assert!(matches!(
+        assert_eq!(
             resolve_call(
                 &ctx,
-                Some(ParametricType(LIST_TYPE, vec![v0]).into()),
+                Some(ParametricType(LIST_TYPE, vec![v0.clone()]).into()),
                 "append",
-                &[v1]
+                &[v1.clone()]
             ),
-            Err(..)
-        ));
+            Err("different variables".to_string())
+        );
     }
 
     #[test]
@@ -559,7 +534,6 @@ mod tests {
                 result: None,
             },
         );
-        let ctx = get_inference_context(ctx);
 
         assert_eq!(
             resolve_call(&ctx, None, "foo", &[ClassType(foo).into()]),
@@ -576,10 +550,10 @@ mod tests {
             Ok(None)
         );
 
-        assert!(matches!(
+        assert_eq!(
             resolve_call(&ctx, None, "foo", &[ClassType(bar).into()]),
-            Err(..)
-        ));
+            Err("not subtype".to_string())
+        );
 
         assert_eq!(
             resolve_call(&ctx, None, "foo1", &[ClassType(foo1).into()]),
@@ -591,10 +565,10 @@ mod tests {
             Ok(None)
         );
 
-        assert!(matches!(
+        assert_eq!(
             resolve_call(&ctx, None, "foo1", &[ClassType(foo).into()]),
-            Err(..)
-        ));
+            Err("not subtype".to_string())
+        );
 
         // virtual class substitution
         assert_eq!(
@@ -609,9 +583,9 @@ mod tests {
             resolve_call(&ctx, None, "foo", &[VirtualClassType(foo2).into()]),
             Ok(None)
         );
-        assert!(matches!(
+        assert_eq!(
             resolve_call(&ctx, None, "foo", &[VirtualClassType(bar).into()]),
-            Err(..)
-        ));
+            Err("not subtype".to_string())
+        );
     }
 }

nac3core/src/lib.rs

@@ -1,33 +1,33 @@
-#![warn(clippy::all)]
-#![allow(clippy::clone_double_ref)]
-
-extern crate num_bigint;
 extern crate inkwell;
+extern crate num_bigint;
 extern crate rustpython_parser;
 
-pub mod type_check;
+pub mod expression;
+pub mod inference;
+mod operators;
+pub mod primitives;
+pub mod typedef;
 
+use std::collections::HashMap;
 use std::error::Error;
 use std::fmt;
 use std::path::Path;
-use std::collections::HashMap;
 
 use num_traits::cast::ToPrimitive;
 
 use rustpython_parser::ast;
 
-use inkwell::OptimizationLevel;
+use inkwell::basic_block;
 use inkwell::builder::Builder;
 use inkwell::context::Context;
 use inkwell::module::Module;
+use inkwell::passes;
 use inkwell::targets::*;
 use inkwell::types;
 use inkwell::types::BasicType;
 use inkwell::values;
-use inkwell::{IntPredicate, FloatPredicate};
-use inkwell::basic_block;
-use inkwell::passes;
-
+use inkwell::OptimizationLevel;
+use inkwell::{FloatPredicate, IntPredicate};
 
 #[derive(Debug)]
 enum CompileErrorKind {
@@ -37,26 +37,25 @@ enum CompileErrorKind {
     IncompatibleTypes,
     UnboundIdentifier,
     BreakOutsideLoop,
-    Internal(&'static str)
+    Internal(&'static str),
 }
 
 impl fmt::Display for CompileErrorKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            CompileErrorKind::Unsupported(feature)
-                => write!(f, "The following Python feature is not supported by NAC3: {}", feature),
-            CompileErrorKind::MissingTypeAnnotation
-                => write!(f, "Missing type annotation"),
-            CompileErrorKind::UnknownTypeAnnotation
-                => write!(f, "Unknown type annotation"),
-            CompileErrorKind::IncompatibleTypes
-                => write!(f, "Incompatible types"),
-            CompileErrorKind::UnboundIdentifier
-                => write!(f, "Unbound identifier"),
-            CompileErrorKind::BreakOutsideLoop
-                => write!(f, "Break outside loop"),
-            CompileErrorKind::Internal(details)
-                => write!(f, "Internal compiler error: {}", details),
+            CompileErrorKind::Unsupported(feature) => write!(
+                f,
+                "The following Python feature is not supported by NAC3: {}",
+                feature
+            ),
+            CompileErrorKind::MissingTypeAnnotation => write!(f, "Missing type annotation"),
+            CompileErrorKind::UnknownTypeAnnotation => write!(f, "Unknown type annotation"),
+            CompileErrorKind::IncompatibleTypes => write!(f, "Incompatible types"),
+            CompileErrorKind::UnboundIdentifier => write!(f, "Unbound identifier"),
+            CompileErrorKind::BreakOutsideLoop => write!(f, "Break outside loop"),
+            CompileErrorKind::Internal(details) => {
+                write!(f, "Internal compiler error: {}", details)
+            }
         }
     }
 }
@@ -107,7 +106,9 @@ impl<'ctx> CodeGen<'ctx> {
         module.add_function("output", fn_type, None);
 
         CodeGen {
-            context, module, pass_manager,
+            context,
+            module,
+            pass_manager,
             builder: context.create_builder(),
             current_source_location: ast::Location::default(),
             namespace: HashMap::new(),
@@ -122,7 +123,7 @@ impl<'ctx> CodeGen<'ctx> {
     fn compile_error(&self, kind: CompileErrorKind) -> CompileError {
         CompileError {
             location: self.current_source_location,
-            kind
+            kind,
         }
     }
 
@@ -133,7 +134,7 @@ impl<'ctx> CodeGen<'ctx> {
             "int64" => Ok(self.context.i64_type().into()),
             "float32" => Ok(self.context.f32_type().into()),
             "float64" => Ok(self.context.f64_type().into()),
-            _ => Err(self.compile_error(CompileErrorKind::UnknownTypeAnnotation))
+            _ => Err(self.compile_error(CompileErrorKind::UnknownTypeAnnotation)),
         }
     }
 
@@ -147,37 +148,53 @@ impl<'ctx> CodeGen<'ctx> {
         is_async: bool,
     ) -> CompileResult<values::FunctionValue<'ctx>> {
         if is_async {
-            return Err(self.compile_error(CompileErrorKind::Unsupported("async functions")))
+            return Err(self.compile_error(CompileErrorKind::Unsupported("async functions")));
         }
         for decorator in decorator_list.iter() {
             self.set_source_location(decorator.location);
             if let ast::ExpressionType::Identifier { name } = &decorator.node {
                 if name != "kernel" && name != "portable" {
-                    return Err(self.compile_error(CompileErrorKind::Unsupported("custom decorators")))
+                    return Err(
+                        self.compile_error(CompileErrorKind::Unsupported("custom decorators"))
+                    );
                 }
             } else {
-                return Err(self.compile_error(CompileErrorKind::Unsupported("decorator must be an identifier")))
+                return Err(self.compile_error(CompileErrorKind::Unsupported(
+                    "decorator must be an identifier",
+                )));
             }
         }
 
-        let args_type = args.args.iter().map(|val| {
-            self.set_source_location(val.location);
-            if let Some(annotation) = &val.annotation {
-                if let ast::ExpressionType::Identifier { name } = &annotation.node {
-                    Ok(self.get_basic_type(&name)?)
+        let args_type = args
+            .args
+            .iter()
+            .map(|val| {
+                self.set_source_location(val.location);
+                if let Some(annotation) = &val.annotation {
+                    if let ast::ExpressionType::Identifier { name } = &annotation.node {
+                        Ok(self.get_basic_type(&name)?)
+                    } else {
+                        Err(self.compile_error(CompileErrorKind::Unsupported(
+                            "type annotation must be an identifier",
+                        )))
+                    }
                 } else {
-                    Err(self.compile_error(CompileErrorKind::Unsupported("type annotation must be an identifier")))
+                    Err(self.compile_error(CompileErrorKind::MissingTypeAnnotation))
                 }
-            } else {
-                Err(self.compile_error(CompileErrorKind::MissingTypeAnnotation))
-            }
-        }).collect::<CompileResult<Vec<types::BasicTypeEnum>>>()?;
+            })
+            .collect::<CompileResult<Vec<types::BasicTypeEnum>>>()?;
         let return_type = if let Some(returns) = returns {
             self.set_source_location(returns.location);
             if let ast::ExpressionType::Identifier { name } = &returns.node {
-                if name == "None" { None } else { Some(self.get_basic_type(name)?) }
+                if name == "None" {
+                    None
+                } else {
+                    Some(self.get_basic_type(name)?)
+                }
             } else {
-                return Err(self.compile_error(CompileErrorKind::Unsupported("type annotation must be an identifier")))
+                return Err(self.compile_error(CompileErrorKind::Unsupported(
+                    "type annotation must be an identifier",
+                )));
             }
         } else {
             None
@@ -185,7 +202,7 @@ impl<'ctx> CodeGen<'ctx> {
 
         let fn_type = match return_type {
             Some(ty) => ty.fn_type(&args_type, false),
-            None => self.context.void_type().fn_type(&args_type, false)
+            None => self.context.void_type().fn_type(&args_type, false),
         };
 
         let function = self.module.add_function(name, fn_type, None);
@@ -206,57 +223,74 @@ impl<'ctx> CodeGen<'ctx> {
 
     fn compile_expression(
         &mut self,
-        expression: &ast::Expression
+        expression: &ast::Expression,
     ) -> CompileResult<values::BasicValueEnum<'ctx>> {
         self.set_source_location(expression.location);
 
         match &expression.node {
             ast::ExpressionType::True => Ok(self.context.bool_type().const_int(1, false).into()),
             ast::ExpressionType::False => Ok(self.context.bool_type().const_int(0, false).into()),
-            ast::ExpressionType::Number { value: ast::Number::Integer { value } } => {
+            ast::ExpressionType::Number {
+                value: ast::Number::Integer { value },
+            } => {
                 let mut bits = value.bits();
                 if value.sign() == num_bigint::Sign::Minus {
                     bits += 1;
                 }
                 match bits {
-                     0..=32 => Ok(self.context.i32_type().const_int(value.to_i32().unwrap() as _, true).into()),
-                    33..=64 => Ok(self.context.i64_type().const_int(value.to_i64().unwrap() as _, true).into()),
-                          _ => Err(self.compile_error(CompileErrorKind::Unsupported("integers larger than 64 bits")))
-                }
-            },
-            ast::ExpressionType::Number { value: ast::Number::Float { value } } => {
-                Ok(self.context.f64_type().const_float(*value).into())
-            },
-            ast::ExpressionType::Identifier { name } => {
-                match self.namespace.get(name) {
-                    Some(value) => Ok(self.builder.build_load(*value, name).into()),
-                    None => Err(self.compile_error(CompileErrorKind::UnboundIdentifier))
+                    0..=32 => Ok(self
+                        .context
+                        .i32_type()
+                        .const_int(value.to_i32().unwrap() as _, true)
+                        .into()),
+                    33..=64 => Ok(self
+                        .context
+                        .i64_type()
+                        .const_int(value.to_i64().unwrap() as _, true)
+                        .into()),
+                    _ => Err(self.compile_error(CompileErrorKind::Unsupported(
+                        "integers larger than 64 bits",
+                    ))),
                 }
+            }
+            ast::ExpressionType::Number {
+                value: ast::Number::Float { value },
+            } => Ok(self.context.f64_type().const_float(*value).into()),
+            ast::ExpressionType::Identifier { name } => match self.namespace.get(name) {
+                Some(value) => Ok(self.builder.build_load(*value, name).into()),
+                None => Err(self.compile_error(CompileErrorKind::UnboundIdentifier)),
             },
             ast::ExpressionType::Unop { op, a } => {
                 let a = self.compile_expression(&a)?;
                 match (op, a) {
-                    (ast::UnaryOperator::Pos, values::BasicValueEnum::IntValue(a))
-                        => Ok(a.into()),
-                    (ast::UnaryOperator::Pos, values::BasicValueEnum::FloatValue(a))
-                        => Ok(a.into()),
-                    (ast::UnaryOperator::Neg, values::BasicValueEnum::IntValue(a))
-                        => Ok(self.builder.build_int_neg(a, "tmpneg").into()),
-                    (ast::UnaryOperator::Neg, values::BasicValueEnum::FloatValue(a))
-                        => Ok(self.builder.build_float_neg(a, "tmpneg").into()),
-                    (ast::UnaryOperator::Inv, values::BasicValueEnum::IntValue(a))
-                        => Ok(self.builder.build_not(a, "tmpnot").into()),
+                    (ast::UnaryOperator::Pos, values::BasicValueEnum::IntValue(a)) => Ok(a.into()),
+                    (ast::UnaryOperator::Pos, values::BasicValueEnum::FloatValue(a)) => {
+                        Ok(a.into())
+                    }
+                    (ast::UnaryOperator::Neg, values::BasicValueEnum::IntValue(a)) => {
+                        Ok(self.builder.build_int_neg(a, "tmpneg").into())
+                    }
+                    (ast::UnaryOperator::Neg, values::BasicValueEnum::FloatValue(a)) => {
+                        Ok(self.builder.build_float_neg(a, "tmpneg").into())
+                    }
+                    (ast::UnaryOperator::Inv, values::BasicValueEnum::IntValue(a)) => {
+                        Ok(self.builder.build_not(a, "tmpnot").into())
+                    }
                     (ast::UnaryOperator::Not, values::BasicValueEnum::IntValue(a)) => {
                         // boolean "not"
                         if a.get_type().get_bit_width() != 1 {
-                            Err(self.compile_error(CompileErrorKind::Unsupported("unimplemented unary operation")))
+                            Err(self.compile_error(CompileErrorKind::Unsupported(
+                                "unimplemented unary operation",
+                            )))
                         } else {
                             Ok(self.builder.build_not(a, "tmpnot").into())
                         }
-                    },
-                    _ => Err(self.compile_error(CompileErrorKind::Unsupported("unimplemented unary operation"))),
+                    }
+                    _ => Err(self.compile_error(CompileErrorKind::Unsupported(
+                        "unimplemented unary operation",
+                    ))),
                 }
-            },
+            }
             ast::ExpressionType::Binop { a, op, b } => {
                 let a = self.compile_expression(&a)?;
                 let b = self.compile_expression(&b)?;
@@ -265,27 +299,53 @@ impl<'ctx> CodeGen<'ctx> {
                 }
                 use ast::Operator::*;
                 match (op, a, b) {
-                    (Add, values::BasicValueEnum::IntValue(a), values::BasicValueEnum::IntValue(b))
-                        => Ok(self.builder.build_int_add(a, b, "tmpadd").into()),
-                    (Sub, values::BasicValueEnum::IntValue(a), values::BasicValueEnum::IntValue(b))
-                        => Ok(self.builder.build_int_sub(a, b, "tmpsub").into()),
-                    (Mult, values::BasicValueEnum::IntValue(a), values::BasicValueEnum::IntValue(b))
-                        => Ok(self.builder.build_int_mul(a, b, "tmpmul").into()),
+                    (
+                        Add,
+                        values::BasicValueEnum::IntValue(a),
+                        values::BasicValueEnum::IntValue(b),
+                    ) => Ok(self.builder.build_int_add(a, b, "tmpadd").into()),
+                    (
+                        Sub,
+                        values::BasicValueEnum::IntValue(a),
+                        values::BasicValueEnum::IntValue(b),
+                    ) => Ok(self.builder.build_int_sub(a, b, "tmpsub").into()),
+                    (
+                        Mult,
+                        values::BasicValueEnum::IntValue(a),
+                        values::BasicValueEnum::IntValue(b),
+                    ) => Ok(self.builder.build_int_mul(a, b, "tmpmul").into()),
 
-                    (Add, values::BasicValueEnum::FloatValue(a), values::BasicValueEnum::FloatValue(b))
-                        => Ok(self.builder.build_float_add(a, b, "tmpadd").into()),
-                    (Sub, values::BasicValueEnum::FloatValue(a), values::BasicValueEnum::FloatValue(b))
-                        => Ok(self.builder.build_float_sub(a, b, "tmpsub").into()),
-                    (Mult, values::BasicValueEnum::FloatValue(a), values::BasicValueEnum::FloatValue(b))
-                        => Ok(self.builder.build_float_mul(a, b, "tmpmul").into()),
+                    (
+                        Add,
+                        values::BasicValueEnum::FloatValue(a),
+                        values::BasicValueEnum::FloatValue(b),
+                    ) => Ok(self.builder.build_float_add(a, b, "tmpadd").into()),
+                    (
+                        Sub,
+                        values::BasicValueEnum::FloatValue(a),
+                        values::BasicValueEnum::FloatValue(b),
+                    ) => Ok(self.builder.build_float_sub(a, b, "tmpsub").into()),
+                    (
+                        Mult,
+                        values::BasicValueEnum::FloatValue(a),
+                        values::BasicValueEnum::FloatValue(b),
+                    ) => Ok(self.builder.build_float_mul(a, b, "tmpmul").into()),
 
-                    (Div, values::BasicValueEnum::FloatValue(a), values::BasicValueEnum::FloatValue(b))
-                        => Ok(self.builder.build_float_div(a, b, "tmpdiv").into()),
-                    (FloorDiv, values::BasicValueEnum::IntValue(a), values::BasicValueEnum::IntValue(b))
-                        => Ok(self.builder.build_int_signed_div(a, b, "tmpdiv").into()),
-                    _ => Err(self.compile_error(CompileErrorKind::Unsupported("unimplemented binary operation"))),
+                    (
+                        Div,
+                        values::BasicValueEnum::FloatValue(a),
+                        values::BasicValueEnum::FloatValue(b),
+                    ) => Ok(self.builder.build_float_div(a, b, "tmpdiv").into()),
+                    (
+                        FloorDiv,
+                        values::BasicValueEnum::IntValue(a),
+                        values::BasicValueEnum::IntValue(b),
+                    ) => Ok(self.builder.build_int_signed_div(a, b, "tmpdiv").into()),
+                    _ => Err(self.compile_error(CompileErrorKind::Unsupported(
+                        "unimplemented binary operation",
+                    ))),
                 }
-            },
+            }
             ast::ExpressionType::Compare { vals, ops } => {
                 let mut vals = vals.iter();
                 let mut ops = ops.iter();
@@ -298,43 +358,93 @@ impl<'ctx> CodeGen<'ctx> {
                         if a.get_type() != b.get_type() {
                             return Err(self.compile_error(CompileErrorKind::IncompatibleTypes));
                         }
-                        let this_result = match (a, b) {
-                            (values::BasicValueEnum::IntValue(a), values::BasicValueEnum::IntValue(b)) => {
-                                match op {
-                                    ast::Comparison::Equal
-                                        => self.builder.build_int_compare(IntPredicate::EQ, a, b, "tmpeq"),
-                                    ast::Comparison::NotEqual
-                                        => self.builder.build_int_compare(IntPredicate::NE, a, b, "tmpne"),
-                                    ast::Comparison::Less
-                                        => self.builder.build_int_compare(IntPredicate::SLT, a, b, "tmpslt"),
-                                    ast::Comparison::LessOrEqual
-                                        => self.builder.build_int_compare(IntPredicate::SLE, a, b, "tmpsle"),
-                                    ast::Comparison::Greater
-                                        => self.builder.build_int_compare(IntPredicate::SGT, a, b, "tmpsgt"),
-                                    ast::Comparison::GreaterOrEqual
-                                        => self.builder.build_int_compare(IntPredicate::SGE, a, b, "tmpsge"),
-                                    _ => return Err(self.compile_error(CompileErrorKind::Unsupported("special comparison"))),
+                        let this_result =
+                            match (a, b) {
+                                (
+                                    values::BasicValueEnum::IntValue(a),
+                                    values::BasicValueEnum::IntValue(b),
+                                ) => {
+                                    match op {
+                                        ast::Comparison::Equal => self.builder.build_int_compare(
+                                            IntPredicate::EQ,
+                                            a,
+                                            b,
+                                            "tmpeq",
+                                        ),
+                                        ast::Comparison::NotEqual => self
+                                            .builder
+                                            .build_int_compare(IntPredicate::NE, a, b, "tmpne"),
+                                        ast::Comparison::Less => self.builder.build_int_compare(
+                                            IntPredicate::SLT,
+                                            a,
+                                            b,
+                                            "tmpslt",
+                                        ),
+                                        ast::Comparison::LessOrEqual => self
+                                            .builder
+                                            .build_int_compare(IntPredicate::SLE, a, b, "tmpsle"),
+                                        ast::Comparison::Greater => self.builder.build_int_compare(
+                                            IntPredicate::SGT,
+                                            a,
+                                            b,
+                                            "tmpsgt",
+                                        ),
+                                        ast::Comparison::GreaterOrEqual => self
+                                            .builder
+                                            .build_int_compare(IntPredicate::SGE, a, b, "tmpsge"),
+                                        _ => {
+                                            return Err(self.compile_error(
+                                                CompileErrorKind::Unsupported("special comparison"),
+                                            ))
+                                        }
+                                    }
                                 }
-                            },
-                            (values::BasicValueEnum::FloatValue(a), values::BasicValueEnum::FloatValue(b)) => {
-                                match op {
-                                    ast::Comparison::Equal
-                                        => self.builder.build_float_compare(FloatPredicate::OEQ, a, b, "tmpoeq"),
-                                    ast::Comparison::NotEqual
-                                        => self.builder.build_float_compare(FloatPredicate::UNE, a, b, "tmpune"),
-                                    ast::Comparison::Less
-                                        => self.builder.build_float_compare(FloatPredicate::OLT, a, b, "tmpolt"),
-                                    ast::Comparison::LessOrEqual
-                                        => self.builder.build_float_compare(FloatPredicate::OLE, a, b, "tmpole"),
-                                    ast::Comparison::Greater
-                                        => self.builder.build_float_compare(FloatPredicate::OGT, a, b, "tmpogt"),
-                                    ast::Comparison::GreaterOrEqual
-                                        => self.builder.build_float_compare(FloatPredicate::OGE, a, b, "tmpoge"),
-                                    _ => return Err(self.compile_error(CompileErrorKind::Unsupported("special comparison"))),
+                                (
+                                    values::BasicValueEnum::FloatValue(a),
+                                    values::BasicValueEnum::FloatValue(b),
+                                ) => match op {
+                                    ast::Comparison::Equal => self.builder.build_float_compare(
+                                        FloatPredicate::OEQ,
+                                        a,
+                                        b,
+                                        "tmpoeq",
+                                    ),
+                                    ast::Comparison::NotEqual => self.builder.build_float_compare(
+                                        FloatPredicate::UNE,
+                                        a,
+                                        b,
+                                        "tmpune",
+                                    ),
+                                    ast::Comparison::Less => self.builder.build_float_compare(
+                                        FloatPredicate::OLT,
+                                        a,
+                                        b,
+                                        "tmpolt",
+                                    ),
+                                    ast::Comparison::LessOrEqual => self
+                                        .builder
+                                        .build_float_compare(FloatPredicate::OLE, a, b, "tmpole"),
+                                    ast::Comparison::Greater => self.builder.build_float_compare(
+                                        FloatPredicate::OGT,
+                                        a,
+                                        b,
+                                        "tmpogt",
+                                    ),
+                                    ast::Comparison::GreaterOrEqual => self
+                                        .builder
+                                        .build_float_compare(FloatPredicate::OGE, a, b, "tmpoge"),
+                                    _ => {
+                                        return Err(self.compile_error(
+                                            CompileErrorKind::Unsupported("special comparison"),
+                                        ))
+                                    }
+                                },
+                                _ => {
+                                    return Err(self.compile_error(CompileErrorKind::Unsupported(
+                                        "comparison of non-numerical types",
+                                    )))
                                 }
-                            },
-                            _ => return Err(self.compile_error(CompileErrorKind::Unsupported("comparison of non-numerical types"))),
-                        };
+                            };
                         match result {
                             Some(last) => {
                                 result = Some(self.builder.build_and(last, this_result, "tmpand"));
@@ -345,15 +455,23 @@ impl<'ctx> CodeGen<'ctx> {
                         }
                         a = b;
                     } else {
-                        return Ok(result.unwrap().into())
+                        return Ok(result.unwrap().into());
                     }
                 }
-            },
-            ast::ExpressionType::Call { function, args, keywords } => {
+            }
+            ast::ExpressionType::Call {
+                function,
+                args,
+                keywords,
+            } => {
                 if !keywords.is_empty() {
-                    return Err(self.compile_error(CompileErrorKind::Unsupported("keyword arguments")))
+                    return Err(
+                        self.compile_error(CompileErrorKind::Unsupported("keyword arguments"))
+                    );
                 }
-                let args = args.iter().map(|val| self.compile_expression(val))
+                let args = args
+                    .iter()
+                    .map(|val| self.compile_expression(val))
                     .collect::<CompileResult<Vec<values::BasicValueEnum>>>()?;
                 self.set_source_location(expression.location);
                 if let ast::ExpressionType::Identifier { name } = &function.node {
@@ -361,67 +479,99 @@ impl<'ctx> CodeGen<'ctx> {
                         ("int32", values::BasicValueEnum::IntValue(a)) => {
                             let nbits = a.get_type().get_bit_width();
                             if nbits < 32 {
-                                Ok(self.builder.build_int_s_extend(a, self.context.i32_type(), "tmpsext").into())
+                                Ok(self
+                                    .builder
+                                    .build_int_s_extend(a, self.context.i32_type(), "tmpsext")
+                                    .into())
                             } else if nbits > 32 {
-                                Ok(self.builder.build_int_truncate(a, self.context.i32_type(), "tmptrunc").into())
+                                Ok(self
+                                    .builder
+                                    .build_int_truncate(a, self.context.i32_type(), "tmptrunc")
+                                    .into())
                             } else {
                                 Ok(a.into())
                             }
-                        },
+                        }
                         ("int64", values::BasicValueEnum::IntValue(a)) => {
                             let nbits = a.get_type().get_bit_width();
                             if nbits < 64 {
-                                Ok(self.builder.build_int_s_extend(a, self.context.i64_type(), "tmpsext").into())
+                                Ok(self
+                                    .builder
+                                    .build_int_s_extend(a, self.context.i64_type(), "tmpsext")
+                                    .into())
                             } else {
                                 Ok(a.into())
                             }
-                        },
-                        ("int32", values::BasicValueEnum::FloatValue(a)) => {
-                            Ok(self.builder.build_float_to_signed_int(a, self.context.i32_type(), "tmpfptosi").into())
-                        },
-                        ("int64", values::BasicValueEnum::FloatValue(a)) => {
-                            Ok(self.builder.build_float_to_signed_int(a, self.context.i64_type(), "tmpfptosi").into())
-                        },
-                        ("float32", values::BasicValueEnum::IntValue(a)) => {
-                            Ok(self.builder.build_signed_int_to_float(a, self.context.f32_type(), "tmpsitofp").into())
-                        },
-                        ("float64", values::BasicValueEnum::IntValue(a)) => {
-                            Ok(self.builder.build_signed_int_to_float(a, self.context.f64_type(), "tmpsitofp").into())
-                        },
+                        }
+                        ("int32", values::BasicValueEnum::FloatValue(a)) => Ok(self
+                            .builder
+                            .build_float_to_signed_int(a, self.context.i32_type(), "tmpfptosi")
+                            .into()),
+                        ("int64", values::BasicValueEnum::FloatValue(a)) => Ok(self
+                            .builder
+                            .build_float_to_signed_int(a, self.context.i64_type(), "tmpfptosi")
+                            .into()),
+                        ("float32", values::BasicValueEnum::IntValue(a)) => Ok(self
+                            .builder
+                            .build_signed_int_to_float(a, self.context.f32_type(), "tmpsitofp")
+                            .into()),
+                        ("float64", values::BasicValueEnum::IntValue(a)) => Ok(self
+                            .builder
+                            .build_signed_int_to_float(a, self.context.f64_type(), "tmpsitofp")
+                            .into()),
                         ("float32", values::BasicValueEnum::FloatValue(a)) => {
                             if a.get_type() == self.context.f64_type() {
-                                Ok(self.builder.build_float_trunc(a, self.context.f32_type(), "tmptrunc").into())
+                                Ok(self
+                                    .builder
+                                    .build_float_trunc(a, self.context.f32_type(), "tmptrunc")
+                                    .into())
                             } else {
                                 Ok(a.into())
                             }
-                        },
+                        }
                         ("float64", values::BasicValueEnum::FloatValue(a)) => {
                             if a.get_type() == self.context.f32_type() {
-                                Ok(self.builder.build_float_ext(a, self.context.f64_type(), "tmpext").into())
+                                Ok(self
+                                    .builder
+                                    .build_float_ext(a, self.context.f64_type(), "tmpext")
+                                    .into())
                             } else {
                                 Ok(a.into())
                             }
-                        },
+                        }
 
                         ("output", values::BasicValueEnum::IntValue(a)) => {
                             let fn_value = self.module.get_function("output").unwrap();
-                            Ok(self.builder.build_call(fn_value, &[a.into()], "call")
-                                .try_as_basic_value().left().unwrap())
-                        },
-                        _ => Err(self.compile_error(CompileErrorKind::Unsupported("unrecognized call")))
+                            Ok(self
+                                .builder
+                                .build_call(fn_value, &[a.into()], "call")
+                                .try_as_basic_value()
+                                .left()
+                                .unwrap())
+                        }
+                        _ => {
+                            Err(self
+                                .compile_error(CompileErrorKind::Unsupported("unrecognized call")))
+                        }
                     }
                 } else {
-                    return Err(self.compile_error(CompileErrorKind::Unsupported("function must be an identifier")))
+                    return Err(self.compile_error(CompileErrorKind::Unsupported(
+                        "function must be an identifier",
+                    )));
                 }
-            },
-            _ => return Err(self.compile_error(CompileErrorKind::Unsupported("unimplemented expression"))),
+            }
+            _ => {
+                return Err(
+                    self.compile_error(CompileErrorKind::Unsupported("unimplemented expression"))
+                )
+            }
         }
     }
 
     fn compile_statement(
         &mut self,
         statement: &ast::Statement,
-        return_type: Option<types::BasicTypeEnum>
+        return_type: Option<types::BasicTypeEnum>,
     ) -> CompileResult<()> {
         self.set_source_location(statement.location);
 
@@ -433,29 +583,43 @@ impl<'ctx> CodeGen<'ctx> {
                     self.set_source_location(target.location);
                     if let ast::ExpressionType::Identifier { name } = &target.node {
                         let builder = &self.builder;
-                        let target = self.namespace.entry(name.clone()).or_insert_with(
-                            || builder.build_alloca(value.get_type(), name));
-                        if target.get_type() != value.get_type().ptr_type(inkwell::AddressSpace::Generic) {
+                        let target = self
+                            .namespace
+                            .entry(name.clone())
+                            .or_insert_with(|| builder.build_alloca(value.get_type(), name));
+                        if target.get_type()
+                            != value.get_type().ptr_type(inkwell::AddressSpace::Generic)
+                        {
                             return Err(self.compile_error(CompileErrorKind::IncompatibleTypes));
                         }
                         builder.build_store(*target, value);
                     } else {
-                        return Err(self.compile_error(CompileErrorKind::Unsupported("assignment target must be an identifier")))
+                        return Err(self.compile_error(CompileErrorKind::Unsupported(
+                            "assignment target must be an identifier",
+                        )));
                     }
                 }
-            },
-            Expression { expression } => { self.compile_expression(expression)?; },
+            }
+            Expression { expression } => {
+                self.compile_expression(expression)?;
+            }
             If { test, body, orelse } => {
                 let test = self.compile_expression(test)?;
                 if test.get_type() != self.context.bool_type().into() {
                     return Err(self.compile_error(CompileErrorKind::IncompatibleTypes));
                 }
 
-                let parent = self.builder.get_insert_block().unwrap().get_parent().unwrap();
+                let parent = self
+                    .builder
+                    .get_insert_block()
+                    .unwrap()
+                    .get_parent()
+                    .unwrap();
                 let then_bb = self.context.append_basic_block(parent, "then");
                 let else_bb = self.context.append_basic_block(parent, "else");
                 let cont_bb = self.context.append_basic_block(parent, "ifcont");
-                self.builder.build_conditional_branch(test.into_int_value(), then_bb, else_bb);
+                self.builder
+                    .build_conditional_branch(test.into_int_value(), then_bb, else_bb);
 
                 self.builder.position_at_end(then_bb);
                 self.compile_suite(body, return_type)?;
@@ -467,9 +631,14 @@ impl<'ctx> CodeGen<'ctx> {
                 }
                 self.builder.build_unconditional_branch(cont_bb);
                 self.builder.position_at_end(cont_bb);
-            },
+            }
             While { test, body, orelse } => {
-                let parent = self.builder.get_insert_block().unwrap().get_parent().unwrap();
+                let parent = self
+                    .builder
+                    .get_insert_block()
+                    .unwrap()
+                    .get_parent()
+                    .unwrap();
                 let test_bb = self.context.append_basic_block(parent, "test");
                 self.builder.build_unconditional_branch(test_bb);
                 self.builder.position_at_end(test_bb);
@@ -481,7 +650,8 @@ impl<'ctx> CodeGen<'ctx> {
                 let then_bb = self.context.append_basic_block(parent, "then");
                 let else_bb = self.context.append_basic_block(parent, "else");
                 let cont_bb = self.context.append_basic_block(parent, "ifcont");
-                self.builder.build_conditional_branch(test.into_int_value(), then_bb, else_bb);
+                self.builder
+                    .build_conditional_branch(test.into_int_value(), then_bb, else_bb);
 
                 self.break_bb = Some(cont_bb);
 
@@ -497,11 +667,16 @@ impl<'ctx> CodeGen<'ctx> {
                 self.builder.position_at_end(cont_bb);
 
                 self.break_bb = None;
-            },
+            }
             Break => {
                 if let Some(bb) = self.break_bb {
                     self.builder.build_unconditional_branch(bb);
-                    let parent = self.builder.get_insert_block().unwrap().get_parent().unwrap();
+                    let parent = self
+                        .builder
+                        .get_insert_block()
+                        .unwrap()
+                        .get_parent()
+                        .unwrap();
                     let unreachable_bb = self.context.append_basic_block(parent, "unreachable");
                     self.builder.position_at_end(unreachable_bb);
                 } else {
@@ -518,13 +693,13 @@ impl<'ctx> CodeGen<'ctx> {
                 } else {
                     return Err(self.compile_error(CompileErrorKind::IncompatibleTypes));
                 }
-            },
+            }
             Return { value: None } => {
                 if !return_type.is_none() {
                     return Err(self.compile_error(CompileErrorKind::IncompatibleTypes));
                 }
                 self.builder.build_return(None);
-            },
+            }
             Pass => (),
             _ => return Err(self.compile_error(CompileErrorKind::Unsupported("special statement"))),
         }
@@ -534,7 +709,7 @@ impl<'ctx> CodeGen<'ctx> {
     fn compile_suite(
         &mut self,
         suite: &ast::Suite,
-        return_type: Option<types::BasicTypeEnum>
+        return_type: Option<types::BasicTypeEnum>,
     ) -> CompileResult<()> {
         for statement in suite.iter() {
             self.compile_statement(statement, return_type)?;
@@ -545,18 +720,22 @@ impl<'ctx> CodeGen<'ctx> {
     pub fn compile_toplevel(&mut self, statement: &ast::Statement) -> CompileResult<()> {
         self.set_source_location(statement.location);
         if let ast::StatementType::FunctionDef {
-                    is_async,
-                    name,
-                    args,
-                    body,
-                    decorator_list,
-                    returns,
-                } = &statement.node {
-            let function = self.compile_function_def(name, args, body, decorator_list, returns, *is_async)?;
+            is_async,
+            name,
+            args,
+            body,
+            decorator_list,
+            returns,
+        } = &statement.node
+        {
+            let function =
+                self.compile_function_def(name, args, body, decorator_list, returns, *is_async)?;
             self.pass_manager.run_on(&function);
             Ok(())
         } else {
-            Err(self.compile_error(CompileErrorKind::Internal("top-level is not a function definition")))
+            Err(self.compile_error(CompileErrorKind::Internal(
+                "top-level is not a function definition",
+            )))
         }
     }
 
@@ -567,8 +746,8 @@ impl<'ctx> CodeGen<'ctx> {
     pub fn output(&self, filename: &str) {
         //let triple = TargetTriple::create("riscv32-none-linux-gnu");
         let triple = TargetMachine::get_default_triple();
-        let target = Target::from_triple(&triple)
-            .expect("couldn't create target from target triple");
+        let target =
+            Target::from_triple(&triple).expect("couldn't create target from target triple");
 
         let target_machine = target
             .create_target_machine(

nac3core/src/primitives.rs

@@ -1,8 +1,6 @@
-use super::context::*;
-use super::typedef::{TypeEnum::*, *};
+use super::typedef::{Type::*, *};
 use std::collections::HashMap;
-
-pub const PRIMITIVES: [&str; 6] = ["int32", "int64", "float", "bool", "list", "tuple"];
+use std::rc::Rc;
 
 pub const TUPLE_TYPE: ParamId = ParamId(0);
 pub const LIST_TYPE: ParamId = ParamId(1);
@@ -12,25 +10,16 @@ pub const INT32_TYPE: PrimitiveId = PrimitiveId(1);
 pub const INT64_TYPE: PrimitiveId = PrimitiveId(2);
 pub const FLOAT_TYPE: PrimitiveId = PrimitiveId(3);
 
-fn impl_math(def: &mut TypeDef, ty: &Type) {
+fn impl_math(def: &mut TypeDef, ty: &Rc<Type>) {
     let result = Some(ty.clone());
     let fun = FnDef {
         args: vec![ty.clone()],
-        result: result.clone(),
+        result,
     };
     def.methods.insert("__add__", fun.clone());
-    def.methods.insert("__iadd__", fun.clone());
     def.methods.insert("__sub__", fun.clone());
-    def.methods.insert("__isub__", fun.clone());
     def.methods.insert("__mul__", fun.clone());
-    def.methods.insert("__imul__", fun.clone());
-    def.methods.insert(
-        "__neg__",
-        FnDef {
-            args: vec![],
-            result,
-        },
-    );
+    def.methods.insert("__neg__", fun.clone());
     def.methods.insert(
         "__truediv__",
         FnDef {
@@ -38,24 +27,12 @@ fn impl_math(def: &mut TypeDef, ty: &Type) {
             result: Some(PrimitiveType(FLOAT_TYPE).into()),
         },
     );
-    if ty.as_ref() == &PrimitiveType(FLOAT_TYPE) {
-        def.methods.insert(
-            "__itruediv__",
-            FnDef {
-                args: vec![ty.clone()],
-                result: Some(PrimitiveType(FLOAT_TYPE).into()),
-            },
-        );
-    }
     def.methods.insert("__floordiv__", fun.clone());
-    def.methods.insert("__ifloordiv__", fun.clone());
     def.methods.insert("__mod__", fun.clone());
-    def.methods.insert("__imod__", fun.clone());
     def.methods.insert("__pow__", fun.clone());
-    def.methods.insert("__ipow__", fun);
 }
 
-fn impl_bits(def: &mut TypeDef, ty: &Type) {
+fn impl_bits(def: &mut TypeDef, ty: &Rc<Type>) {
     let result = Some(ty.clone());
     let fun = FnDef {
         args: vec![PrimitiveType(INT32_TYPE).into()],
@@ -63,7 +40,7 @@ fn impl_bits(def: &mut TypeDef, ty: &Type) {
     };
 
     def.methods.insert("__lshift__", fun.clone());
-    def.methods.insert("__rshift__", fun);
+    def.methods.insert("__rshift__", fun.clone());
     def.methods.insert(
         "__xor__",
         FnDef {
@@ -73,17 +50,17 @@ fn impl_bits(def: &mut TypeDef, ty: &Type) {
     );
 }
 
-fn impl_eq(def: &mut TypeDef, ty: &Type) {
+fn impl_eq(def: &mut TypeDef, ty: &Rc<Type>) {
     let fun = FnDef {
         args: vec![ty.clone()],
         result: Some(PrimitiveType(BOOL_TYPE).into()),
     };
 
     def.methods.insert("__eq__", fun.clone());
-    def.methods.insert("__ne__", fun);
+    def.methods.insert("__ne__", fun.clone());
 }
 
-fn impl_order(def: &mut TypeDef, ty: &Type) {
+fn impl_order(def: &mut TypeDef, ty: &Rc<Type>) {
     let fun = FnDef {
         args: vec![ty.clone()],
         result: Some(PrimitiveType(BOOL_TYPE).into()),
@@ -92,10 +69,10 @@ fn impl_order(def: &mut TypeDef, ty: &Type) {
     def.methods.insert("__lt__", fun.clone());
     def.methods.insert("__gt__", fun.clone());
     def.methods.insert("__le__", fun.clone());
-    def.methods.insert("__ge__", fun);
+    def.methods.insert("__ge__", fun.clone());
 }
 
-pub fn basic_ctx() -> TopLevelContext<'static> {
+pub fn basic_ctx() -> GlobalContext<'static> {
     let primitives = [
         TypeDef {
             name: "bool",
@@ -119,25 +96,25 @@ pub fn basic_ctx() -> TopLevelContext<'static> {
         },
     ]
     .to_vec();
-    let mut ctx = TopLevelContext::new(primitives);
+    let mut ctx = GlobalContext::new(primitives);
 
-    let b = ctx.get_primitive(BOOL_TYPE);
-    let b_def = ctx.get_primitive_def_mut(BOOL_TYPE);
+    let b_def = ctx.get_primitive_mut(BOOL_TYPE);
+    let b = PrimitiveType(BOOL_TYPE).into();
     impl_eq(b_def, &b);
-    let int32 = ctx.get_primitive(INT32_TYPE);
-    let int32_def = ctx.get_primitive_def_mut(INT32_TYPE);
+    let int32_def = ctx.get_primitive_mut(INT32_TYPE);
+    let int32 = PrimitiveType(INT32_TYPE).into();
     impl_math(int32_def, &int32);
     impl_bits(int32_def, &int32);
     impl_order(int32_def, &int32);
     impl_eq(int32_def, &int32);
-    let int64 = ctx.get_primitive(INT64_TYPE);
-    let int64_def = ctx.get_primitive_def_mut(INT64_TYPE);
+    let int64_def = ctx.get_primitive_mut(INT64_TYPE);
+    let int64 = PrimitiveType(INT64_TYPE).into();
     impl_math(int64_def, &int64);
     impl_bits(int64_def, &int64);
     impl_order(int64_def, &int64);
     impl_eq(int64_def, &int64);
-    let float = ctx.get_primitive(FLOAT_TYPE);
-    let float_def = ctx.get_primitive_def_mut(FLOAT_TYPE);
+    let float_def = ctx.get_primitive_mut(FLOAT_TYPE);
+    let float = PrimitiveType(FLOAT_TYPE).into();
     impl_math(float_def, &float);
     impl_order(float_def, &float);
     impl_eq(float_def, &float);
@@ -192,7 +169,7 @@ pub fn basic_ctx() -> TopLevelContext<'static> {
     ctx.add_fn(
         "float",
         FnDef {
-            args,
+            args: args.clone(),
             result: Some(PrimitiveType(FLOAT_TYPE).into()),
         },
     );

nac3core/src/type_check/context/inference_context.rs

@@ -1,228 +0,0 @@
-use super::super::typedef::*;
-use super::TopLevelContext;
-use std::boxed::Box;
-use std::collections::HashMap;
-
-struct ContextStack<'a> {
-    /// stack level, starts from 0
-    level: u32,
-    /// stack of variable definitions containing (id, def, level) where `def` is the original
-    /// definition in `level-1`.
-    var_defs: Vec<(usize, VarDef<'a>, u32)>,
-    /// stack of symbol definitions containing (name, level) where `level` is the smallest level
-    /// where the name is assigned a value
-    sym_def: Vec<(&'a str, u32)>,
-}
-
-pub struct InferenceContext<'a> {
-    /// top level context
-    top_level: TopLevelContext<'a>,
-
-    /// list of primitive instances
-    primitives: Vec<Type>,
-    /// list of variable instances
-    variables: Vec<Type>,
-    /// identifier to type mapping.
-    sym_table: HashMap<&'a str, Type>,
-    /// resolution function reference, that may resolve unbounded identifiers to some type
-    resolution_fn: Box<dyn FnMut(&str) -> Result<Type, String>>,
-    /// stack
-    stack: ContextStack<'a>,
-    /// return type
-    result: Option<Type>,
-}
-
-// non-trivial implementations here
-impl<'a> InferenceContext<'a> {
-    /// return a new `InferenceContext` from `TopLevelContext` and resolution function.
-    pub fn new(
-        top_level: TopLevelContext,
-        resolution_fn: Box<dyn FnMut(&str) -> Result<Type, String>>,
-    ) -> InferenceContext {
-        let primitives = (0..top_level.primitive_defs.len())
-            .map(|v| TypeEnum::PrimitiveType(PrimitiveId(v)).into())
-            .collect();
-        let variables = (0..top_level.var_defs.len())
-            .map(|v| TypeEnum::TypeVariable(VariableId(v)).into())
-            .collect();
-        InferenceContext {
-            top_level,
-            primitives,
-            variables,
-            sym_table: HashMap::new(),
-            resolution_fn,
-            stack: ContextStack {
-                level: 0,
-                var_defs: Vec::new(),
-                sym_def: Vec::new(),
-            },
-            result: None,
-        }
-    }
-
-    /// execute the function with new scope.
-    /// variable assignment would be limited within the scope (not readable outside), and type
-    /// variable type guard would be limited within the scope.
-    /// returns the list of variables assigned within the scope, and the result of the function
-    pub fn with_scope<F, R>(&mut self, f: F) -> (Vec<(&'a str, Type)>, R)
-    where
-        F: FnOnce(&mut Self) -> R,
-    {
-        self.stack.level += 1;
-        let result = f(self);
-        self.stack.level -= 1;
-        while !self.stack.var_defs.is_empty() {
-            let (_, _, level) = self.stack.var_defs.last().unwrap();
-            if *level > self.stack.level {
-                let (id, def, _) = self.stack.var_defs.pop().unwrap();
-                self.top_level.var_defs[id] = def;
-            } else {
-                break;
-            }
-        }
-        let mut poped_names = Vec::new();
-        while !self.stack.sym_def.is_empty() {
-            let (_, level) = self.stack.sym_def.last().unwrap();
-            if *level > self.stack.level {
-                let (name, _) = self.stack.sym_def.pop().unwrap();
-                let ty = self.sym_table.remove(name).unwrap();
-                poped_names.push((name, ty));
-            } else {
-                break;
-            }
-        }
-        (poped_names, result)
-    }
-
-    /// assign a type to an identifier.
-    /// may return error if the identifier was defined but with different type
-    pub fn assign(&mut self, name: &'a str, ty: Type) -> Result<Type, String> {
-        if let Some(t) = self.sym_table.get_mut(name) {
-            if t == &ty {
-                Ok(ty)
-            } else {
-                Err("different types".into())
-            }
-        } else {
-            self.stack.sym_def.push((name, self.stack.level));
-            self.sym_table.insert(name, ty.clone());
-            Ok(ty)
-        }
-    }
-
-    /// check if an identifier is already defined
-    pub fn defined(&self, name: &str) -> bool {
-        self.sym_table.get(name).is_some()
-    }
-
-    /// get the type of an identifier
-    /// may return error if the identifier is not defined, and cannot be resolved with the
-    /// resolution function.
-    pub fn resolve(&mut self, name: &str) -> Result<Type, String> {
-        if let Some(t) = self.sym_table.get(name) {
-            Ok(t.clone())
-        } else {
-            self.resolution_fn.as_mut()(name)
-        }
-    }
-
-    /// restrict the bound of a type variable by replacing its definition.
-    /// used for implementing type guard
-    pub fn restrict(&mut self, id: VariableId, mut def: VarDef<'a>) {
-        std::mem::swap(self.top_level.var_defs.get_mut(id.0).unwrap(), &mut def);
-        self.stack.var_defs.push((id.0, def, self.stack.level));
-    }
-
-    pub fn set_result(&mut self, result: Option<Type>) {
-        self.result = result;
-    }
-}
-
-// trivial getters:
-impl<'a> InferenceContext<'a> {
-    pub fn get_primitive(&self, id: PrimitiveId) -> Type {
-        self.primitives.get(id.0).unwrap().clone()
-    }
-    pub fn get_variable(&self, id: VariableId) -> Type {
-        self.variables.get(id.0).unwrap().clone()
-    }
-
-    pub fn get_fn_def(&self, name: &str) -> Option<&FnDef> {
-        self.top_level.fn_table.get(name)
-    }
-    pub fn get_primitive_def(&self, id: PrimitiveId) -> &TypeDef {
-        self.top_level.primitive_defs.get(id.0).unwrap()
-    }
-    pub fn get_class_def(&self, id: ClassId) -> &ClassDef {
-        self.top_level.class_defs.get(id.0).unwrap()
-    }
-    pub fn get_parametric_def(&self, id: ParamId) -> &ParametricDef {
-        self.top_level.parametric_defs.get(id.0).unwrap()
-    }
-    pub fn get_variable_def(&self, id: VariableId) -> &VarDef {
-        self.top_level.var_defs.get(id.0).unwrap()
-    }
-    pub fn get_type(&self, name: &str) -> Option<Type> {
-        self.top_level.get_type(name)
-    }
-    pub fn get_result(&self) -> Option<Type> {
-        self.result.clone()
-    }
-}
-
-impl TypeEnum {
-    pub fn subst(&self, map: &HashMap<VariableId, Type>) -> TypeEnum {
-        match self {
-            TypeEnum::TypeVariable(id) => map.get(id).map(|v| v.as_ref()).unwrap_or(self).clone(),
-            TypeEnum::ParametricType(id, params) => TypeEnum::ParametricType(
-                *id,
-                params
-                    .iter()
-                    .map(|v| v.as_ref().subst(map).into())
-                    .collect(),
-            ),
-            _ => self.clone(),
-        }
-    }
-
-    pub fn inv_subst(&self, map: &[(Type, Type)]) -> Type {
-        for (from, to) in map.iter() {
-            if self == from.as_ref() {
-                return to.clone();
-            }
-        }
-        match self {
-            TypeEnum::ParametricType(id, params) => TypeEnum::ParametricType(
-                *id,
-                params.iter().map(|v| v.as_ref().inv_subst(map)).collect(),
-            ),
-            _ => self.clone(),
-        }
-        .into()
-    }
-
-    pub fn get_subst(&self, ctx: &InferenceContext) -> HashMap<VariableId, Type> {
-        match self {
-            TypeEnum::ParametricType(id, params) => {
-                let vars = &ctx.get_parametric_def(*id).params;
-                vars.iter()
-                    .zip(params)
-                    .map(|(v, p)| (*v, p.as_ref().clone().into()))
-                    .collect()
-            }
-            // if this proves to be slow, we can use option type
-            _ => HashMap::new(),
-        }
-    }
-
-    pub fn get_base<'a>(&'a self, ctx: &'a InferenceContext) -> Option<&'a TypeDef> {
-        match self {
-            TypeEnum::PrimitiveType(id) => Some(ctx.get_primitive_def(*id)),
-            TypeEnum::ClassType(id) | TypeEnum::VirtualClassType(id) => {
-                Some(&ctx.get_class_def(*id).base)
-            }
-            TypeEnum::ParametricType(id, _) => Some(&ctx.get_parametric_def(*id).base),
-            _ => None,
-        }
-    }
-}

nac3core/src/type_check/context/mod.rs

@@ -1,4 +0,0 @@
-mod inference_context;
-mod top_level_context;
-pub use inference_context::InferenceContext;
-pub use top_level_context::TopLevelContext;

nac3core/src/type_check/context/top_level_context.rs

@@ -1,138 +0,0 @@
-use super::super::typedef::*;
-use std::collections::HashMap;
-use std::rc::Rc;
-
-/// Structure for storing top-level type definitions.
-/// Used for collecting type signature from source code.
-/// Can be converted to `InferenceContext` for type inference in functions.
-pub struct TopLevelContext<'a> {
-    /// List of primitive definitions.
-    pub(super) primitive_defs: Vec<TypeDef<'a>>,
-    /// List of class definitions.
-    pub(super) class_defs: Vec<ClassDef<'a>>,
-    /// List of parametric type definitions.
-    pub(super) parametric_defs: Vec<ParametricDef<'a>>,
-    /// List of type variable definitions.
-    pub(super) var_defs: Vec<VarDef<'a>>,
-    /// Function name to signature mapping.
-    pub(super) fn_table: HashMap<&'a str, FnDef>,
-    /// Type name to type mapping.
-    pub(super) sym_table: HashMap<&'a str, Type>,
-
-    primitives: Vec<Type>,
-    variables: Vec<Type>,
-}
-
-impl<'a> TopLevelContext<'a> {
-    pub fn new(primitive_defs: Vec<TypeDef<'a>>) -> TopLevelContext {
-        let mut sym_table = HashMap::new();
-        let mut primitives = Vec::new();
-        for (i, t) in primitive_defs.iter().enumerate() {
-            primitives.push(TypeEnum::PrimitiveType(PrimitiveId(i)).into());
-            sym_table.insert(t.name, TypeEnum::PrimitiveType(PrimitiveId(i)).into());
-        }
-        TopLevelContext {
-            primitive_defs,
-            class_defs: Vec::new(),
-            parametric_defs: Vec::new(),
-            var_defs: Vec::new(),
-            fn_table: HashMap::new(),
-            sym_table,
-            primitives,
-            variables: Vec::new(),
-        }
-    }
-
-    pub fn add_class(&mut self, def: ClassDef<'a>) -> ClassId {
-        self.sym_table.insert(
-            def.base.name,
-            TypeEnum::ClassType(ClassId(self.class_defs.len())).into(),
-        );
-        self.class_defs.push(def);
-        ClassId(self.class_defs.len() - 1)
-    }
-
-    pub fn add_parametric(&mut self, def: ParametricDef<'a>) -> ParamId {
-        let params = def
-            .params
-            .iter()
-            .map(|&v| Rc::new(TypeEnum::TypeVariable(v)))
-            .collect();
-        self.sym_table.insert(
-            def.base.name,
-            TypeEnum::ParametricType(ParamId(self.parametric_defs.len()), params).into(),
-        );
-        self.parametric_defs.push(def);
-        ParamId(self.parametric_defs.len() - 1)
-    }
-
-    pub fn add_variable(&mut self, def: VarDef<'a>) -> VariableId {
-        self.sym_table.insert(
-            def.name,
-            TypeEnum::TypeVariable(VariableId(self.var_defs.len())).into(),
-        );
-        self.add_variable_private(def)
-    }
-
-    pub fn add_variable_private(&mut self, def: VarDef<'a>) -> VariableId {
-        self.var_defs.push(def);
-        self.variables
-            .push(TypeEnum::TypeVariable(VariableId(self.var_defs.len() - 1)).into());
-        VariableId(self.var_defs.len() - 1)
-    }
-
-    pub fn add_fn(&mut self, name: &'a str, def: FnDef) {
-        self.fn_table.insert(name, def);
-    }
-
-    pub fn get_fn_def(&self, name: &str) -> Option<&FnDef> {
-        self.fn_table.get(name)
-    }
-
-    pub fn get_primitive_def_mut(&mut self, id: PrimitiveId) -> &mut TypeDef<'a> {
-        self.primitive_defs.get_mut(id.0).unwrap()
-    }
-
-    pub fn get_primitive_def(&self, id: PrimitiveId) -> &TypeDef {
-        self.primitive_defs.get(id.0).unwrap()
-    }
-
-    pub fn get_class_def_mut(&mut self, id: ClassId) -> &mut ClassDef<'a> {
-        self.class_defs.get_mut(id.0).unwrap()
-    }
-
-    pub fn get_class_def(&self, id: ClassId) -> &ClassDef {
-        self.class_defs.get(id.0).unwrap()
-    }
-
-    pub fn get_parametric_def_mut(&mut self, id: ParamId) -> &mut ParametricDef<'a> {
-        self.parametric_defs.get_mut(id.0).unwrap()
-    }
-
-    pub fn get_parametric_def(&self, id: ParamId) -> &ParametricDef {
-        self.parametric_defs.get(id.0).unwrap()
-    }
-
-    pub fn get_variable_def_mut(&mut self, id: VariableId) -> &mut VarDef<'a> {
-        self.var_defs.get_mut(id.0).unwrap()
-    }
-
-    pub fn get_variable_def(&self, id: VariableId) -> &VarDef {
-        self.var_defs.get(id.0).unwrap()
-    }
-
-    pub fn get_primitive(&self, id: PrimitiveId) -> Type {
-        self.primitives.get(id.0).unwrap().clone()
-    }
-
-    pub fn get_variable(&self, id: VariableId) -> Type {
-        self.variables.get(id.0).unwrap().clone()
-    }
-
-    pub fn get_type(&self, name: &str) -> Option<Type> {
-        // TODO: handle name visibility
-        // possibly by passing a function from outside to tell what names are allowed, and what are
-        // not...
-        self.sym_table.get(name).cloned()
-    }
-}

nac3core/src/type_check/expression_inference.rs

@@ -1,967 +0,0 @@
-use super::context::InferenceContext;
-use super::inference_core::resolve_call;
-use super::magic_methods::*;
-use super::primitives::*;
-use super::typedef::{Type, TypeEnum::*};
-use rustpython_parser::ast::{
-    Comparison, Comprehension, ComprehensionKind, Expression, ExpressionType, Operator,
-    UnaryOperator,
-};
-use std::convert::TryInto;
-
-type ParserResult = Result<Option<Type>, String>;
-
-pub fn infer_expr<'a>(
-    ctx: &mut InferenceContext<'a>,
-    expr: &'a Expression,
-) -> ParserResult {
-    match &expr.node {
-        ExpressionType::Number { value } => infer_constant(ctx, value),
-        ExpressionType::Identifier { name } => infer_identifier(ctx, name),
-        ExpressionType::List { elements } => infer_list(ctx, elements),
-        ExpressionType::Tuple { elements } => infer_tuple(ctx, elements),
-        ExpressionType::Attribute { value, name } => infer_attribute(ctx, value, name),
-        ExpressionType::BoolOp { values, .. } => infer_bool_ops(ctx, values),
-        ExpressionType::Binop { a, b, op } => infer_bin_ops(ctx, op, a, b),
-        ExpressionType::Unop { op, a } => infer_unary_ops(ctx, op, a),
-        ExpressionType::Compare { vals, ops } => infer_compare(ctx, vals, ops),
-        ExpressionType::Call {
-            args,
-            function,
-            keywords,
-        } => {
-            if !keywords.is_empty() {
-                Err("keyword is not supported".into())
-            } else {
-                infer_call(ctx, &args, &function)
-            }
-        }
-        ExpressionType::Subscript { a, b } => infer_subscript(ctx, a, b),
-        ExpressionType::IfExpression { test, body, orelse } => {
-            infer_if_expr(ctx, &test, &body, orelse)
-        }
-        ExpressionType::Comprehension { kind, generators } => match kind.as_ref() {
-            ComprehensionKind::List { element } => {
-                if generators.len() == 1 {
-                    infer_list_comprehension(ctx, element, &generators[0])
-                } else {
-                    Err("only 1 generator statement is supported".into())
-                }
-            }
-            _ => Err("only list comprehension is supported".into()),
-        },
-        ExpressionType::True | ExpressionType::False => Ok(Some(ctx.get_primitive(BOOL_TYPE))),
-        _ => Err("not supported".into()),
-    }
-}
-
-fn infer_constant(
-    ctx: &mut InferenceContext,
-    value: &rustpython_parser::ast::Number,
-) -> ParserResult {
-    use rustpython_parser::ast::Number;
-    match value {
-        Number::Integer { value } => {
-            let int32: Result<i32, _> = value.try_into();
-            if int32.is_ok() {
-                Ok(Some(ctx.get_primitive(INT32_TYPE)))
-            } else {
-                let int64: Result<i64, _> = value.try_into();
-                if int64.is_ok() {
-                    Ok(Some(ctx.get_primitive(INT64_TYPE)))
-                } else {
-                    Err("integer out of range".into())
-                }
-            }
-        }
-        Number::Float { .. } => Ok(Some(ctx.get_primitive(FLOAT_TYPE))),
-        _ => Err("not supported".into()),
-    }
-}
-
-fn infer_identifier(ctx: &mut InferenceContext, name: &str) -> ParserResult {
-    Ok(Some(ctx.resolve(name)?))
-}
-
-fn infer_list<'a>(
-    ctx: &mut InferenceContext<'a>,
-    elements: &'a [Expression],
-) -> ParserResult {
-    if elements.is_empty() {
-        return Ok(Some(ParametricType(LIST_TYPE, vec![BotType.into()]).into()));
-    }
-
-    let mut types = elements.iter().map(|v| infer_expr(ctx, v));
-
-    let head = types.next().unwrap()?;
-    if head.is_none() {
-        return Err("list elements must have some type".into());
-    }
-    for v in types {
-        if v? != head {
-            return Err("inhomogeneous list is not allowed".into());
-        }
-    }
-    Ok(Some(ParametricType(LIST_TYPE, vec![head.unwrap()]).into()))
-}
-
-fn infer_tuple<'a>(
-    ctx: &mut InferenceContext<'a>,
-    elements: &'a [Expression],
-) -> ParserResult {
-    let types: Result<Option<Vec<_>>, String> =
-        elements.iter().map(|v| infer_expr(ctx, v)).collect();
-    if let Some(t) = types? {
-        Ok(Some(ParametricType(TUPLE_TYPE, t).into()))
-    } else {
-        Err("tuple elements must have some type".into())
-    }
-}
-
-fn infer_attribute<'a>(
-    ctx: &mut InferenceContext<'a>,
-    value: &'a Expression,
-    name: &str,
-) -> ParserResult {
-    let value = infer_expr(ctx, value)?.ok_or_else(|| "no value".to_string())?;
-    if let TypeVariable(id) = value.as_ref() {
-        let v = ctx.get_variable_def(*id);
-        if v.bound.is_empty() {
-            return Err("no fields on unbounded type variable".into());
-        }
-        let ty = v.bound[0].get_base(ctx).and_then(|v| v.fields.get(name));
-        if ty.is_none() {
-            return Err("unknown field".into());
-        }
-        for x in v.bound[1..].iter() {
-            let ty1 = x.get_base(ctx).and_then(|v| v.fields.get(name));
-            if ty1 != ty {
-                return Err("unknown field (type mismatch between variants)".into());
-            }
-        }
-        return Ok(Some(ty.unwrap().clone()));
-    }
-
-    match value.get_base(ctx) {
-        Some(b) => match b.fields.get(name) {
-            Some(t) => Ok(Some(t.clone())),
-            None => Err("no such field".into()),
-        },
-        None => Err("this object has no fields".into()),
-    }
-}
-
-fn infer_bool_ops<'a>(ctx: &mut InferenceContext<'a>, values: &'a [Expression]) -> ParserResult {
-    assert_eq!(values.len(), 2);
-    let left = infer_expr(ctx, &values[0])?.ok_or_else(|| "no value".to_string())?;
-    let right = infer_expr(ctx, &values[1])?.ok_or_else(|| "no value".to_string())?;
-
-    let b = ctx.get_primitive(BOOL_TYPE);
-    if left == b && right == b {
-        Ok(Some(b))
-    } else {
-        Err("bool operands must be bool".into())
-    }
-}
-
-fn infer_bin_ops<'a>(
-    ctx: &mut InferenceContext<'a>,
-    op: &Operator,
-    left: &'a Expression,
-    right: &'a Expression,
-) -> ParserResult {
-    let left = infer_expr(ctx, left)?.ok_or_else(|| "no value".to_string())?;
-    let right = infer_expr(ctx, right)?.ok_or_else(|| "no value".to_string())?;
-    let fun = binop_name(op);
-    resolve_call(ctx, Some(left), fun, &[right])
-}
-
-fn infer_unary_ops<'a>(
-    ctx: &mut InferenceContext<'a>,
-    op: &UnaryOperator,
-    obj: &'a Expression,
-) -> ParserResult {
-    let ty = infer_expr(ctx, obj)?.ok_or_else(|| "no value".to_string())?;
-    if let UnaryOperator::Not = op {
-        if ty == ctx.get_primitive(BOOL_TYPE) {
-            Ok(Some(ty))
-        } else {
-            Err("logical not must be applied to bool".into())
-        }
-    } else {
-        resolve_call(ctx, Some(ty), unaryop_name(op), &[])
-    }
-}
-
-fn infer_compare<'a>(
-    ctx: &mut InferenceContext<'a>,
-    vals: &'a [Expression],
-    ops: &'a [Comparison],
-) -> ParserResult {
-    let types: Result<Option<Vec<_>>, _> = vals.iter().map(|v| infer_expr(ctx, v)).collect();
-    let types = types?;
-    if types.is_none() {
-        return Err("comparison operands must have type".into());
-    }
-    let types = types.unwrap();
-    let boolean = ctx.get_primitive(BOOL_TYPE);
-    let left = &types[..types.len() - 1];
-    let right = &types[1..];
-
-    for ((a, b), op) in left.iter().zip(right.iter()).zip(ops.iter()) {
-        let fun = comparison_name(op).ok_or_else(|| "unsupported comparison".to_string())?;
-        let ty = resolve_call(ctx, Some(a.clone()), fun, &[b.clone()])?;
-        if ty.is_none() || ty.unwrap() != boolean {
-            return Err("comparison result must be boolean".into());
-        }
-    }
-    Ok(Some(boolean))
-}
-
-fn infer_call<'a>(
-    ctx: &mut InferenceContext<'a>,
-    args: &'a [Expression],
-    function: &'a Expression,
-) -> ParserResult {
-    let types: Result<Option<Vec<_>>, _> = args.iter().map(|v| infer_expr(ctx, v)).collect();
-    let types = types?;
-    if types.is_none() {
-        return Err("function params must have type".into());
-    }
-
-    let (obj, fun) = match &function.node {
-        ExpressionType::Identifier { name } => (None, name),
-        ExpressionType::Attribute { value, name } => (
-            Some(infer_expr(ctx, &value)?.ok_or_else(|| "no value".to_string())?),
-            name,
-        ),
-        _ => return Err("not supported".into()),
-    };
-    resolve_call(ctx, obj, fun.as_str(), &types.unwrap())
-}
-
-fn infer_subscript<'a>(
-    ctx: &mut InferenceContext<'a>,
-    a: &'a Expression,
-    b: &'a Expression,
-) -> ParserResult {
-    let a = infer_expr(ctx, a)?.ok_or_else(|| "no value".to_string())?;
-    let t = if let ParametricType(LIST_TYPE, ls) = a.as_ref() {
-        ls[0].clone()
-    } else {
-        return Err("subscript is not supported for types other than list".into());
-    };
-
-    match &b.node {
-        ExpressionType::Slice { elements } => {
-            let int32 = ctx.get_primitive(INT32_TYPE);
-            let types: Result<Option<Vec<_>>, _> = elements
-                .iter()
-                .map(|v| {
-                    if let ExpressionType::None = v.node {
-                        Ok(Some(int32.clone()))
-                    } else {
-                        infer_expr(ctx, v)
-                    }
-                })
-                .collect();
-            let types = types?.ok_or_else(|| "slice must have type".to_string())?;
-            if types.iter().all(|v| v == &int32) {
-                Ok(Some(a))
-            } else {
-                Err("slice must be int32 type".into())
-            }
-        }
-        _ => {
-            let b = infer_expr(ctx, b)?.ok_or_else(|| "no value".to_string())?;
-            if b == ctx.get_primitive(INT32_TYPE) {
-                Ok(Some(t))
-            } else {
-                Err("index must be either slice or int32".into())
-            }
-        }
-    }
-}
-
-fn infer_if_expr<'a>(
-    ctx: &mut InferenceContext<'a>,
-    test: &'a Expression,
-    body: &'a Expression,
-    orelse: &'a Expression,
-) -> ParserResult {
-    let test = infer_expr(ctx, test)?.ok_or_else(|| "no value".to_string())?;
-    if test != ctx.get_primitive(BOOL_TYPE) {
-        return Err("test should be bool".into());
-    }
-
-    let body = infer_expr(ctx, body)?;
-    let orelse = infer_expr(ctx, orelse)?;
-    if body.as_ref() == orelse.as_ref() {
-        Ok(body)
-    } else {
-        Err("divergent type".into())
-    }
-}
-
-pub fn infer_simple_binding<'a>(
-    ctx: &mut InferenceContext<'a>,
-    name: &'a Expression,
-    ty: Type,
-) -> Result<(), String> {
-    match &name.node {
-        ExpressionType::Identifier { name } => {
-            if name == "_" {
-                Ok(())
-            } else if ctx.defined(name.as_str()) {
-                Err("duplicated naming".into())
-            } else {
-                ctx.assign(name.as_str(), ty)?;
-                Ok(())
-            }
-        }
-        ExpressionType::Tuple { elements } => {
-            if let ParametricType(TUPLE_TYPE, ls) = ty.as_ref() {
-                if elements.len() == ls.len() {
-                    for (a, b) in elements.iter().zip(ls.iter()) {
-                        infer_simple_binding(ctx, a, b.clone())?;
-                    }
-                    Ok(())
-                } else {
-                    Err("different length".into())
-                }
-            } else {
-                Err("not supported".into())
-            }
-        }
-        _ => Err("not supported".into()),
-    }
-}
-
-fn infer_list_comprehension<'a>(
-    ctx: &mut InferenceContext<'a>,
-    element: &'a Expression,
-    comprehension: &'a Comprehension,
-) -> ParserResult {
-    if comprehension.is_async {
-        return Err("async is not supported".into());
-    }
-
-    let iter = infer_expr(ctx, &comprehension.iter)?.ok_or_else(|| "no value".to_string())?;
-    if let ParametricType(LIST_TYPE, ls) = iter.as_ref() {
-        ctx.with_scope(|ctx| {
-            infer_simple_binding(ctx, &comprehension.target, ls[0].clone())?;
-
-            let boolean = ctx.get_primitive(BOOL_TYPE);
-            for test in comprehension.ifs.iter() {
-                let result =
-                    infer_expr(ctx, test)?.ok_or_else(|| "no value in test".to_string())?;
-                if result != boolean {
-                    return Err("test must be bool".into());
-                }
-            }
-            let result = infer_expr(ctx, element)?.ok_or_else(|| "no value")?;
-            Ok(Some(ParametricType(LIST_TYPE, vec![result]).into()))
-        })
-        .1
-    } else {
-        Err("iteration is supported for list only".into())
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::{
-        super::{context::*, typedef::*},
-        *,
-    };
-    use rustpython_parser::parser::parse_expression;
-    use std::collections::HashMap;
-    use std::rc::Rc;
-
-    fn get_inference_context(ctx: TopLevelContext) -> InferenceContext {
-        InferenceContext::new(ctx, Box::new(|_| Err("unbounded identifier".into())))
-    }
-
-    #[test]
-    fn test_constants() {
-        let ctx = basic_ctx();
-        let mut ctx = get_inference_context(ctx);
-
-        let ast = parse_expression("123").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("2147483647").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("2147483648").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT64_TYPE));
-
-        let ast = parse_expression("9223372036854775807").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT64_TYPE));
-
-        let ast = parse_expression("9223372036854775808").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("integer out of range".into()));
-
-        let ast = parse_expression("123.456").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(FLOAT_TYPE));
-
-        let ast = parse_expression("True").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(BOOL_TYPE));
-
-        let ast = parse_expression("False").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(BOOL_TYPE));
-    }
-
-    #[test]
-    fn test_identifier() {
-        let ctx = basic_ctx();
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("abc", ctx.get_primitive(INT32_TYPE)).unwrap();
-
-        let ast = parse_expression("abc").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("ab").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("unbounded identifier".into()));
-    }
-
-    #[test]
-    fn test_list() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "foo",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("abc", ctx.get_primitive(INT32_TYPE)).unwrap();
-        // def is reserved...
-        ctx.assign("efg", ctx.get_primitive(INT32_TYPE)).unwrap();
-        ctx.assign("xyz", ctx.get_primitive(FLOAT_TYPE)).unwrap();
-
-        let ast = parse_expression("[]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result.unwrap().unwrap(),
-            ParametricType(LIST_TYPE, vec![BotType.into()]).into()
-        );
-
-        let ast = parse_expression("[abc]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result.unwrap().unwrap(),
-            ParametricType(LIST_TYPE, vec![ctx.get_primitive(INT32_TYPE)]).into()
-        );
-
-        let ast = parse_expression("[abc, efg]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result.unwrap().unwrap(),
-            ParametricType(LIST_TYPE, vec![ctx.get_primitive(INT32_TYPE)]).into()
-        );
-
-        let ast = parse_expression("[abc, efg, xyz]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("inhomogeneous list is not allowed".into()));
-
-        let ast = parse_expression("[foo()]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("list elements must have some type".into()));
-    }
-
-    #[test]
-    fn test_tuple() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "foo",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("abc", ctx.get_primitive(INT32_TYPE)).unwrap();
-        ctx.assign("efg", ctx.get_primitive(FLOAT_TYPE)).unwrap();
-
-        let ast = parse_expression("(abc, efg)").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result.unwrap().unwrap(),
-            ParametricType(
-                TUPLE_TYPE,
-                vec![ctx.get_primitive(INT32_TYPE), ctx.get_primitive(FLOAT_TYPE)]
-            )
-            .into()
-        );
-
-        let ast = parse_expression("(abc, efg, foo())").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("tuple elements must have some type".into()));
-    }
-
-    #[test]
-    fn test_attribute() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "none",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-        let int32 = ctx.get_primitive(INT32_TYPE);
-        let float = ctx.get_primitive(FLOAT_TYPE);
-
-        let foo = ctx.add_class(ClassDef {
-            base: TypeDef {
-                name: "Foo",
-                fields: HashMap::new(),
-                methods: HashMap::new(),
-            },
-            parents: vec![],
-        });
-        let foo_def = ctx.get_class_def_mut(foo);
-        foo_def.base.fields.insert("a", int32.clone());
-        foo_def.base.fields.insert("b", ClassType(foo).into());
-        foo_def.base.fields.insert("c", int32.clone());
-
-        let bar = ctx.add_class(ClassDef {
-            base: TypeDef {
-                name: "Bar",
-                fields: HashMap::new(),
-                methods: HashMap::new(),
-            },
-            parents: vec![],
-        });
-        let bar_def = ctx.get_class_def_mut(bar);
-        bar_def.base.fields.insert("a", int32);
-        bar_def.base.fields.insert("b", ClassType(bar).into());
-        bar_def.base.fields.insert("c", float);
-
-        let v0 = ctx.add_variable(VarDef {
-            name: "v0",
-            bound: vec![],
-        });
-
-        let v1 = ctx.add_variable(VarDef {
-            name: "v1",
-            bound: vec![ClassType(foo).into(), ClassType(bar).into()],
-        });
-
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("foo", Rc::new(ClassType(foo))).unwrap();
-        ctx.assign("bar", Rc::new(ClassType(bar))).unwrap();
-        ctx.assign("foobar", Rc::new(VirtualClassType(foo)))
-            .unwrap();
-        ctx.assign("v0", ctx.get_variable(v0)).unwrap();
-        ctx.assign("v1", ctx.get_variable(v1)).unwrap();
-        ctx.assign("bot", Rc::new(BotType)).unwrap();
-
-        let ast = parse_expression("foo.a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("foo.d").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no such field".into()));
-
-        let ast = parse_expression("foobar.a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("v0.a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no fields on unbounded type variable".into()));
-
-        let ast = parse_expression("v1.a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        // shall we support this?
-        let ast = parse_expression("v1.b").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result,
-            Err("unknown field (type mismatch between variants)".into())
-        );
-        // assert_eq!(result.unwrap().unwrap(), TypeVariable(v1).into());
-
-        let ast = parse_expression("v1.c").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result,
-            Err("unknown field (type mismatch between variants)".into())
-        );
-
-        let ast = parse_expression("v1.d").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("unknown field".into()));
-
-        let ast = parse_expression("none().a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no value".into()));
-
-        let ast = parse_expression("bot.a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("this object has no fields".into()));
-    }
-
-    #[test]
-    fn test_bool_ops() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "none",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-        let mut ctx = get_inference_context(ctx);
-
-        let ast = parse_expression("True and False").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(BOOL_TYPE));
-
-        let ast = parse_expression("True and none()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no value".into()));
-
-        let ast = parse_expression("True and 123").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("bool operands must be bool".into()));
-    }
-
-    #[test]
-    fn test_bin_ops() {
-        let mut ctx = basic_ctx();
-        let v0 = ctx.add_variable(VarDef {
-            name: "v0",
-            bound: vec![ctx.get_primitive(INT32_TYPE), ctx.get_primitive(INT64_TYPE)],
-        });
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("a", TypeVariable(v0).into()).unwrap();
-
-        let ast = parse_expression("1 + 2 + 3").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("a + a + a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), TypeVariable(v0).into());
-    }
-
-    #[test]
-    fn test_unary_ops() {
-        let mut ctx = basic_ctx();
-        let v0 = ctx.add_variable(VarDef {
-            name: "v0",
-            bound: vec![ctx.get_primitive(INT32_TYPE), ctx.get_primitive(INT64_TYPE)],
-        });
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("a", TypeVariable(v0).into()).unwrap();
-
-        let ast = parse_expression("-(123)").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("-a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), TypeVariable(v0).into());
-
-        let ast = parse_expression("not True").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(BOOL_TYPE));
-
-        let ast = parse_expression("not (1)").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("logical not must be applied to bool".into()));
-    }
-
-    #[test]
-    fn test_compare() {
-        let mut ctx = basic_ctx();
-        let v0 = ctx.add_variable(VarDef {
-            name: "v0",
-            bound: vec![ctx.get_primitive(INT32_TYPE), ctx.get_primitive(INT64_TYPE)],
-        });
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("a", TypeVariable(v0).into()).unwrap();
-
-        let ast = parse_expression("a == a == a").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(BOOL_TYPE));
-
-        let ast = parse_expression("a == a == 1").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("different types".into()));
-
-        let ast = parse_expression("True > False").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no such function".into()));
-
-        let ast = parse_expression("True in False").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("unsupported comparison".into()));
-    }
-
-    #[test]
-    fn test_call() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "none",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-
-        let foo = ctx.add_class(ClassDef {
-            base: TypeDef {
-                name: "Foo",
-                fields: HashMap::new(),
-                methods: HashMap::new(),
-            },
-            parents: vec![],
-        });
-        let foo_def = ctx.get_class_def_mut(foo);
-        foo_def.base.methods.insert(
-            "a",
-            FnDef {
-                args: vec![],
-                result: Some(Rc::new(ClassType(foo))),
-            },
-        );
-
-        let bar = ctx.add_class(ClassDef {
-            base: TypeDef {
-                name: "Bar",
-                fields: HashMap::new(),
-                methods: HashMap::new(),
-            },
-            parents: vec![],
-        });
-        let bar_def = ctx.get_class_def_mut(bar);
-        bar_def.base.methods.insert(
-            "a",
-            FnDef {
-                args: vec![],
-                result: Some(Rc::new(ClassType(bar))),
-            },
-        );
-
-        let v0 = ctx.add_variable(VarDef {
-            name: "v0",
-            bound: vec![],
-        });
-        let v1 = ctx.add_variable(VarDef {
-            name: "v1",
-            bound: vec![ClassType(foo).into(), ClassType(bar).into()],
-        });
-        let v2 = ctx.add_variable(VarDef {
-            name: "v2",
-            bound: vec![
-                ClassType(foo).into(),
-                ClassType(bar).into(),
-                ctx.get_primitive(INT32_TYPE),
-            ],
-        });
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("foo", Rc::new(ClassType(foo))).unwrap();
-        ctx.assign("bar", Rc::new(ClassType(bar))).unwrap();
-        ctx.assign("foobar", Rc::new(VirtualClassType(foo)))
-            .unwrap();
-        ctx.assign("v0", ctx.get_variable(v0)).unwrap();
-        ctx.assign("v1", ctx.get_variable(v1)).unwrap();
-        ctx.assign("v2", ctx.get_variable(v2)).unwrap();
-        ctx.assign("bot", Rc::new(BotType)).unwrap();
-
-        let ast = parse_expression("foo.a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ClassType(foo).into());
-
-        let ast = parse_expression("v1.a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), TypeVariable(v1).into());
-
-        let ast = parse_expression("foobar.a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ClassType(foo).into());
-
-        let ast = parse_expression("none().a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no value".into()));
-
-        let ast = parse_expression("bot.a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("not supported".into()));
-
-        let ast = parse_expression("[][0].a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("not supported".into()));
-
-        let ast = parse_expression("v0.a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("unbounded type var".into()));
-
-        let ast = parse_expression("v2.a()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no such function".into()));
-    }
-
-    #[test]
-    fn infer_subscript() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "none",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-        let mut ctx = get_inference_context(ctx);
-
-        let ast = parse_expression("[1, 2, 3][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("[[1]][0][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("[1, 2, 3][1:2]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result.unwrap().unwrap(),
-            ParametricType(LIST_TYPE, vec![ctx.get_primitive(INT32_TYPE)]).into()
-        );
-
-        let ast = parse_expression("[1, 2, 3][1:2:2]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result.unwrap().unwrap(),
-            ParametricType(LIST_TYPE, vec![ctx.get_primitive(INT32_TYPE)]).into()
-        );
-
-        let ast = parse_expression("[1, 2, 3][1:1.2]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("slice must be int32 type".into()));
-
-        let ast = parse_expression("[1, 2, 3][1:none()]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("slice must have type".into()));
-
-        let ast = parse_expression("[1, 2, 3][1.2]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("index must be either slice or int32".into()));
-
-        let ast = parse_expression("[1, 2, 3][none()]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no value".into()));
-
-        let ast = parse_expression("none()[1.2]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no value".into()));
-
-        let ast = parse_expression("123[1]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result,
-            Err("subscript is not supported for types other than list".into())
-        );
-    }
-
-    #[test]
-    fn test_if_expr() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "none",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-        let mut ctx = get_inference_context(ctx);
-
-        let ast = parse_expression("1 if True else 0").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), ctx.get_primitive(INT32_TYPE));
-
-        let ast = parse_expression("none() if True else none()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap(), None);
-
-        let ast = parse_expression("none() if 1 else none()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("test should be bool".into()));
-
-        let ast = parse_expression("1 if True else none()").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("divergent type".into()));
-    }
-
-    #[test]
-    fn test_list_comp() {
-        let mut ctx = basic_ctx();
-        ctx.add_fn(
-            "none",
-            FnDef {
-                args: vec![],
-                result: None,
-            },
-        );
-        let int32 = ctx.get_primitive(INT32_TYPE);
-        let mut ctx = get_inference_context(ctx);
-        ctx.assign("z", int32.clone()).unwrap();
-
-        let ast = parse_expression("[x for x in [(1, 2), (2, 3), (3, 4)]][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result.unwrap().unwrap(),
-            ParametricType(TUPLE_TYPE, vec![int32.clone(), int32.clone()]).into()
-        );
-
-        let ast = parse_expression("[x for (x, y) in [(1, 2), (2, 3), (3, 4)]][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), int32);
-
-        let ast =
-            parse_expression("[x for (x, y) in [(1, 2), (2, 3), (3, 4)] if x > 0][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result.unwrap().unwrap(), int32);
-
-        let ast = parse_expression("[x for (x, y) in [(1, 2), (2, 3), (3, 4)] if x][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("test must be bool".into()));
-
-        let ast = parse_expression("[y for x in []][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("unbounded identifier".into()));
-
-        let ast = parse_expression("[none() for x in []][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("no value".into()));
-
-        let ast = parse_expression("[z for z in []][0]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(result, Err("duplicated naming".into()));
-
-        let ast = parse_expression("[x for x in [] for y in []]").unwrap();
-        let result = infer_expr(&mut ctx, &ast);
-        assert_eq!(
-            result,
-            Err("only 1 generator statement is supported".into())
-        );
-    }
-}

nac3core/src/type_check/mod.rs

@@ -1,9 +0,0 @@
-pub mod context;
-pub mod expression_inference;
-pub mod inference_core;
-mod magic_methods;
-pub mod primitives;
-pub mod statement_check;
-pub mod typedef;
-pub mod signature;
-

nac3core/src/type_check/signature.rs

@@ -1,503 +0,0 @@
-/// obtain class and function signature from AST
-use super::context::TopLevelContext;
-use super::primitives::*;
-use super::typedef::*;
-use rustpython_parser::ast::{
-    ComprehensionKind, ExpressionType, Statement, StatementType, StringGroup,
-};
-use std::collections::HashMap;
-
-// TODO: fix condition checking, return error message instead of panic...
-
-fn typename_from_expr<'a>(typenames: &mut Vec<&'a str>, expr: &'a ExpressionType) {
-    match expr {
-        ExpressionType::Identifier { name } => typenames.push(&name),
-        ExpressionType::String { value } => match value {
-            StringGroup::Constant { value } => typenames.push(&value),
-            _ => unimplemented!(),
-        },
-        ExpressionType::Subscript { a, b } => {
-            typename_from_expr(typenames, &b.node);
-            typename_from_expr(typenames, &a.node)
-        }
-        _ => unimplemented!(),
-    }
-}
-
-fn typename_from_fn<'a>(typenames: &mut Vec<&'a str>, fun: &'a StatementType) {
-    match fun {
-        StatementType::FunctionDef { args, returns, .. } => {
-            for arg in args.args.iter() {
-                if let Some(ann) = &arg.annotation {
-                    typename_from_expr(typenames, &ann.node);
-                }
-            }
-            if let Some(returns) = &returns {
-                typename_from_expr(typenames, &returns.node);
-            }
-        }
-        _ => unreachable!(),
-    }
-}
-
-fn name_from_expr<'a>(expr: &'a ExpressionType) -> &'a str {
-    match &expr {
-        ExpressionType::Identifier { name } => &name,
-        ExpressionType::String { value } => match value {
-            StringGroup::Constant { value } => &value,
-            _ => unimplemented!(),
-        },
-        _ => unimplemented!(),
-    }
-}
-
-fn type_from_expr<'a>(ctx: &'a TopLevelContext, expr: &'a ExpressionType) -> Result<Type, String> {
-    match expr {
-        ExpressionType::Identifier { name } => {
-            ctx.get_type(name).ok_or_else(|| "no such type".into())
-        }
-        ExpressionType::String { value } => match value {
-            StringGroup::Constant { value } => {
-                ctx.get_type(&value).ok_or_else(|| "no such type".into())
-            }
-            _ => unimplemented!(),
-        },
-        ExpressionType::Subscript { a, b } => {
-            if let ExpressionType::Identifier { name } = &a.node {
-                match name.as_str() {
-                    "list" => {
-                        let ty = type_from_expr(ctx, &b.node)?;
-                        Ok(TypeEnum::ParametricType(LIST_TYPE, vec![ty]).into())
-                    }
-                    "tuple" => {
-                        if let ExpressionType::Tuple { elements } = &b.node {
-                            let ty_list: Result<Vec<_>, _> = elements
-                                .iter()
-                                .map(|v| type_from_expr(ctx, &v.node))
-                                .collect();
-                            Ok(TypeEnum::ParametricType(TUPLE_TYPE, ty_list?).into())
-                        } else {
-                            Err("unsupported format".into())
-                        }
-                    }
-                    _ => Err("no such parameterized type".into()),
-                }
-            } else {
-                // we require a to be an identifier, for a[b]
-                Err("unsupported format".into())
-            }
-        }
-        _ => Err("unsupported format".into()),
-    }
-}
-
-pub fn get_typenames<'a>(stmts: &'a [Statement]) -> (Vec<&'a str>, Vec<&'a str>) {
-    let mut classes = Vec::new();
-    let mut typenames = Vec::new();
-    for stmt in stmts.iter() {
-        match &stmt.node {
-            StatementType::ClassDef {
-                name, body, bases, ..
-            } => {
-                // check if class is not duplicated...
-                // and annotations
-                classes.push(&name[..]);
-                for base in bases.iter() {
-                    let name = name_from_expr(&base.node);
-                    typenames.push(name);
-                }
-                // may check if fields/functions are not duplicated
-                for stmt in body.iter() {
-                    match &stmt.node {
-                        StatementType::AnnAssign { annotation, .. } => {
-                            typename_from_expr(&mut typenames, &annotation.node)
-                        }
-                        StatementType::FunctionDef { .. } => {
-                            typename_from_fn(&mut typenames, &stmt.node);
-                        }
-                        _ => unimplemented!(),
-                    }
-                }
-            }
-            StatementType::FunctionDef { .. } => {
-                // may check annotations
-                typename_from_fn(&mut typenames, &stmt.node);
-            }
-            _ => (),
-        }
-    }
-    let mut unknowns = Vec::new();
-    for n in typenames {
-        if !PRIMITIVES.contains(&n) && !classes.contains(&n) && !unknowns.contains(&n) {
-            unknowns.push(n);
-        }
-    }
-    (classes, unknowns)
-}
-
-fn resolve_function<'a>(
-    ctx: &'a TopLevelContext,
-    fun: &'a StatementType,
-    method: bool,
-) -> Result<FnDef, String> {
-    if let StatementType::FunctionDef { args, returns, .. } = &fun {
-        let args = if method {
-            args.args[1..].iter()
-        } else {
-            args.args.iter()
-        };
-        let args: Result<Vec<_>, _> = args
-            .map(|arg| type_from_expr(ctx, &arg.annotation.as_ref().unwrap().node))
-            .collect();
-        let args = args?;
-        let result = match returns {
-            Some(v) => Some(type_from_expr(ctx, &v.node)?),
-            None => None,
-        };
-        Ok(FnDef { args, result })
-    } else {
-        unreachable!()
-    }
-}
-
-fn get_expr_unknowns<'a>(
-    defined: &mut Vec<&'a str>,
-    unknowns: &mut Vec<&'a str>,
-    expr: &'a ExpressionType,
-) {
-    match expr {
-        ExpressionType::BoolOp { values, .. } => {
-            for v in values.iter() {
-                get_expr_unknowns(defined, unknowns, &v.node)
-            }
-        }
-        ExpressionType::Binop { a, b, .. } => {
-            get_expr_unknowns(defined, unknowns, &a.node);
-            get_expr_unknowns(defined, unknowns, &b.node);
-        }
-        ExpressionType::Subscript { a, b } => {
-            get_expr_unknowns(defined, unknowns, &a.node);
-            get_expr_unknowns(defined, unknowns, &b.node);
-        }
-        ExpressionType::Unop { a, .. } => {
-            get_expr_unknowns(defined, unknowns, &a.node);
-        }
-        ExpressionType::Compare { vals, .. } => {
-            for v in vals.iter() {
-                get_expr_unknowns(defined, unknowns, &v.node)
-            }
-        }
-        ExpressionType::Attribute { value, .. } => {
-            get_expr_unknowns(defined, unknowns, &value.node);
-        }
-        ExpressionType::Call { function, args, .. } => {
-            get_expr_unknowns(defined, unknowns, &function.node);
-            for v in args.iter() {
-                get_expr_unknowns(defined, unknowns, &v.node)
-            }
-        }
-        ExpressionType::List { elements } => {
-            for v in elements.iter() {
-                get_expr_unknowns(defined, unknowns, &v.node)
-            }
-        }
-        ExpressionType::Tuple { elements } => {
-            for v in elements.iter() {
-                get_expr_unknowns(defined, unknowns, &v.node)
-            }
-        }
-        ExpressionType::Comprehension { kind, generators } => {
-            if generators.len() != 1 {
-                unimplemented!()
-            }
-            let g = &generators[0];
-            get_expr_unknowns(defined, unknowns, &g.iter.node);
-            let mut scoped = defined.clone();
-            get_expr_unknowns(defined, &mut scoped, &g.target.node);
-            for if_expr in g.ifs.iter() {
-                get_expr_unknowns(&mut scoped, unknowns, &if_expr.node);
-            }
-            match kind.as_ref() {
-                ComprehensionKind::List { element } => {
-                    get_expr_unknowns(&mut scoped, unknowns, &element.node);
-                }
-                _ => unimplemented!(),
-            }
-        }
-        ExpressionType::Slice { elements } => {
-            for v in elements.iter() {
-                get_expr_unknowns(defined, unknowns, &v.node);
-            }
-        }
-        ExpressionType::Identifier { name } => {
-            if !defined.contains(&name.as_str()) && !unknowns.contains(&name.as_str()) {
-                unknowns.push(name);
-            }
-        }
-        ExpressionType::IfExpression { test, body, orelse } => {
-            get_expr_unknowns(defined, unknowns, &test.node);
-            get_expr_unknowns(defined, unknowns, &body.node);
-            get_expr_unknowns(defined, unknowns, &orelse.node);
-        }
-        _ => (),
-    };
-}
-
-struct ExprPattern<'a>(&'a ExpressionType, Vec<usize>, bool);
-
-impl<'a> ExprPattern<'a> {
-    fn new(expr: &'a ExpressionType) -> ExprPattern {
-        let mut pattern = ExprPattern(expr, Vec::new(), true);
-        pattern.find_leaf();
-        pattern
-    }
-
-    fn pointed(&mut self) -> &'a ExpressionType {
-        let mut current = self.0;
-        for v in self.1.iter() {
-            if let ExpressionType::Tuple { elements } = current {
-                current = &elements[*v].node
-            } else {
-                unreachable!()
-            }
-        }
-        current
-    }
-
-    fn find_leaf(&mut self) {
-        let mut current = self.pointed();
-        while let ExpressionType::Tuple { elements } = current {
-            if elements.is_empty() {
-                break;
-            }
-            current = &elements[0].node;
-            self.1.push(0);
-        }
-    }
-
-    fn inc(&mut self) -> bool {
-        loop {
-            if self.1.is_empty() {
-                return false;
-            }
-            let ind = self.1.pop().unwrap() + 1;
-            let parent = self.pointed();
-            if let ExpressionType::Tuple { elements } = parent {
-                if ind < elements.len() {
-                    self.1.push(ind);
-                    self.find_leaf();
-                    return true;
-                }
-            } else {
-                unreachable!()
-            }
-        }
-    }
-}
-
-impl<'a> Iterator for ExprPattern<'a> {
-    type Item = &'a ExpressionType;
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.2 {
-            self.2 = false;
-            Some(self.pointed())
-        } else if self.inc() {
-            Some(self.pointed())
-        } else {
-            None
-        }
-    }
-}
-
-fn get_stmt_unknowns<'a>(
-    defined: &mut Vec<&'a str>,
-    unknowns: &mut Vec<&'a str>,
-    stmts: &'a [Statement],
-) {
-    for stmt in stmts.iter() {
-        match &stmt.node {
-            StatementType::Return { value } => {
-                if let Some(value) = value {
-                    get_expr_unknowns(defined, unknowns, &value.node);
-                }
-            }
-            StatementType::Assign { targets, value } => {
-                get_expr_unknowns(defined, unknowns, &value.node);
-                for target in targets.iter() {
-                    for node in ExprPattern::new(&target.node).into_iter() {
-                        if let ExpressionType::Identifier { name } = node {
-                            let name = name.as_str();
-                            if !defined.contains(&name) {
-                                defined.push(name);
-                            }
-                        } else {
-                            get_expr_unknowns(defined, unknowns, node);
-                        }
-                    }
-                }
-            }
-            StatementType::AugAssign { target, value, .. } => {
-                get_expr_unknowns(defined, unknowns, &target.node);
-                get_expr_unknowns(defined, unknowns, &value.node);
-            }
-            StatementType::AnnAssign { target, value, .. } => {
-                get_expr_unknowns(defined, unknowns, &target.node);
-                if let Some(value) = value {
-                    get_expr_unknowns(defined, unknowns, &value.node);
-                }
-            }
-            StatementType::Expression { expression } => {
-                get_expr_unknowns(defined, unknowns, &expression.node);
-            }
-            StatementType::Global { names } => {
-                for name in names.iter() {
-                    let name = name.as_str();
-                    if !unknowns.contains(&name) {
-                        unknowns.push(name);
-                    }
-                }
-            }
-            StatementType::If { test, body, orelse }
-            | StatementType::While { test, body, orelse } => {
-                get_expr_unknowns(defined, unknowns, &test.node);
-                // we are not very strict at this point...
-                // some identifiers not treated as unknowns may not be resolved
-                // but should be checked during type inference
-                get_stmt_unknowns(defined, unknowns, body.as_slice());
-                if let Some(orelse) = orelse {
-                    get_stmt_unknowns(defined, unknowns, orelse.as_slice());
-                }
-            }
-            StatementType::For { is_async, target, iter, body, orelse } => {
-                if *is_async {
-                    unimplemented!()
-                }
-                get_expr_unknowns(defined, unknowns, &iter.node);
-                for node in ExprPattern::new(&target.node).into_iter() {
-                    if let ExpressionType::Identifier { name } = node {
-                        let name = name.as_str();
-                        if !defined.contains(&name) {
-                            defined.push(name);
-                        }
-                    } else {
-                        get_expr_unknowns(defined, unknowns, node);
-                    }
-                }
-                get_stmt_unknowns(defined, unknowns, body.as_slice());
-                if let Some(orelse) = orelse {
-                    get_stmt_unknowns(defined, unknowns, orelse.as_slice());
-                }
-            }
-            _ => (),
-        }
-    }
-}
-
-pub fn resolve_signatures<'a>(ctx: &mut TopLevelContext<'a>, stmts: &'a [Statement]) {
-    for stmt in stmts.iter() {
-        match &stmt.node {
-            StatementType::ClassDef {
-                name, bases, body, ..
-            } => {
-                let mut parents = Vec::new();
-                for base in bases.iter() {
-                    let name = name_from_expr(&base.node);
-                    let c = ctx.get_type(name).unwrap();
-                    let id = if let TypeEnum::ClassType(id) = c.as_ref() {
-                        *id
-                    } else {
-                        unreachable!()
-                    };
-                    parents.push(id);
-                }
-
-                let mut fields = HashMap::new();
-                let mut functions = HashMap::new();
-
-                for stmt in body.iter() {
-                    match &stmt.node {
-                        StatementType::AnnAssign {
-                            target, annotation, ..
-                        } => {
-                            let name = name_from_expr(&target.node);
-                            let ty = type_from_expr(ctx, &annotation.node).unwrap();
-                            fields.insert(name, ty);
-                        }
-                        StatementType::FunctionDef { name, .. } => {
-                            functions.insert(
-                                &name[..],
-                                resolve_function(ctx, &stmt.node, true).unwrap(),
-                            );
-                        }
-                        _ => unimplemented!(),
-                    }
-                }
-
-                let class = ctx.get_type(name).unwrap();
-                let class = if let TypeEnum::ClassType(id) = class.as_ref() {
-                    ctx.get_class_def_mut(*id)
-                } else {
-                    unreachable!()
-                };
-                class.parents.extend_from_slice(&parents);
-                class.base.fields.clone_from(&fields);
-                class.base.methods.clone_from(&functions);
-            }
-            StatementType::FunctionDef { name, .. } => {
-                ctx.add_fn(&name[..], resolve_function(ctx, &stmt.node, false).unwrap());
-            }
-            _ => unimplemented!(),
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use indoc::indoc;
-    use rustpython_parser::parser::{parse_program, parse_statement};
-
-    #[test]
-    fn test_get_classes() {
-        let ast = parse_program(indoc! {"
-            class Foo:
-                a: int32
-                b: Test
-
-                def test(self, a: int32) -> Test2:
-                    return self.b
-
-            class Bar(Foo, 'FooBar'):
-                def test2(self, a: list[Foo]) -> Test2:
-                    return self.b
-
-                def test3(self, a: list[FooBar2]) -> Test2:
-                    return self.b
-        " })
-        .unwrap();
-        let (mut classes, mut unknowns) = get_typenames(&ast.statements);
-        let classes_count = classes.len();
-        let unknowns_count = unknowns.len();
-        classes.sort();
-        unknowns.sort();
-        assert_eq!(classes.len(), classes_count);
-        assert_eq!(unknowns.len(), unknowns_count);
-        assert_eq!(&classes, &["Bar", "Foo"]);
-        assert_eq!(&unknowns, &["FooBar", "FooBar2", "Test", "Test2"]);
-    }
-
-    #[test]
-    fn test_assignment() {
-        let ast = parse_statement(indoc! {"
-            ((a, b), c[i]) = core.foo(x, get_y())
-        " })
-        .unwrap();
-        let mut defined = Vec::new();
-        let mut unknowns = Vec::new();
-        get_stmt_unknowns(&mut defined, &mut unknowns, ast.as_slice());
-        defined.sort();
-        unknowns.sort();
-        assert_eq!(defined.as_slice(), &["a", "b"]);
-        assert_eq!(unknowns.as_slice(), &["c", "core", "get_y", "i", "x"]);
-    }
-}

nac3core/src/type_check/statement_check.rs

@@ -1,572 +0,0 @@
-use super::context::InferenceContext;
-use super::expression_inference::{infer_expr, infer_simple_binding};
-use super::inference_core::resolve_call;
-use super::magic_methods::binop_assign_name;
-use super::primitives::*;
-use super::typedef::{Type, TypeEnum::*};
-use rustpython_parser::ast::*;
-
-pub fn check_stmts<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    stmts: &'b [Statement],
-) -> Result<bool, String> {
-    for stmt in stmts.iter() {
-        match &stmt.node {
-            StatementType::Assign { targets, value } => {
-                check_assign(ctx, targets.as_slice(), &value)?;
-            }
-            StatementType::AugAssign { target, op, value } => {
-                check_aug_assign(ctx, &target, op, &value)?;
-            }
-            StatementType::If { test, body, orelse } => {
-                if check_if(ctx, test, body.as_slice(), orelse)? {
-                    return Ok(true);
-                }
-            }
-            StatementType::While { test, body, orelse } => {
-                check_while_stmt(ctx, test, body.as_slice(), orelse)?;
-            }
-            StatementType::For {
-                is_async,
-                target,
-                iter,
-                body,
-                orelse,
-            } => {
-                if *is_async {
-                    return Err("async for is not supported".to_string());
-                }
-                check_for_stmt(ctx, target, iter, body.as_slice(), orelse)?;
-            }
-            StatementType::Return { value } => {
-                let result = ctx.get_result();
-                let t = if let Some(value) = value {
-                    infer_expr(ctx, value)?
-                } else {
-                    None
-                };
-                return if t == result {
-                    Ok(true)
-                } else {
-                    Err("return type mismatch".to_string())
-                };
-            }
-            StatementType::Continue | StatementType::Break => {
-                continue;
-            }
-            _ => return Err("not supported".to_string()),
-        }
-    }
-    Ok(false)
-}
-
-fn get_target_type<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    target: &'b Expression,
-) -> Result<Type, String> {
-    match &target.node {
-        ExpressionType::Subscript { a, b } => {
-            let int32 = ctx.get_primitive(INT32_TYPE);
-            if infer_expr(ctx, &a)? == Some(int32) {
-                let b = get_target_type(ctx, &b)?;
-                if let ParametricType(LIST_TYPE, t) = b.as_ref() {
-                    Ok(t[0].clone())
-                } else {
-                    Err("subscript is only supported for list".to_string())
-                }
-            } else {
-                Err("subscript must be int32".to_string())
-            }
-        }
-        ExpressionType::Attribute { value, name } => {
-            let t = get_target_type(ctx, &value)?;
-            let base = t.get_base(ctx).ok_or_else(|| "no attributes".to_string())?;
-            Ok(base
-                .fields
-                .get(name.as_str())
-                .ok_or_else(|| "no such attribute")?
-                .clone())
-        }
-        ExpressionType::Identifier { name } => Ok(ctx.resolve(name.as_str())?),
-        _ => Err("not supported".to_string()),
-    }
-}
-
-fn check_stmt_binding<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    target: &'b Expression,
-    ty: Type,
-) -> Result<(), String> {
-    match &target.node {
-        ExpressionType::Identifier { name } => {
-            if name.as_str() == "_" {
-                Ok(())
-            } else {
-                match ctx.resolve(name.as_str()) {
-                    Ok(t) if t == ty => Ok(()),
-                    Err(_) => {
-                        ctx.assign(name.as_str(), ty).unwrap();
-                        Ok(())
-                    }
-                    _ => Err("conflicting type".into()),
-                }
-            }
-        }
-        ExpressionType::Tuple { elements } => {
-            if let ParametricType(TUPLE_TYPE, ls) = ty.as_ref() {
-                if ls.len() != elements.len() {
-                    return Err("incorrect pattern length".into());
-                }
-                for (x, y) in elements.iter().zip(ls.iter()) {
-                    check_stmt_binding(ctx, x, y.clone())?;
-                }
-                Ok(())
-            } else {
-                Err("pattern matching supports tuple only".into())
-            }
-        }
-        _ => {
-            let t = get_target_type(ctx, target)?;
-            if ty == t {
-                Ok(())
-            } else {
-                Err("type mismatch".into())
-            }
-        }
-    }
-}
-
-fn check_assign<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    targets: &'b [Expression],
-    value: &'b Expression,
-) -> Result<(), String> {
-    let ty = infer_expr(ctx, value)?.ok_or_else(|| "no value".to_string())?;
-    for t in targets.iter() {
-        check_stmt_binding(ctx, t, ty.clone())?;
-    }
-    Ok(())
-}
-
-fn check_aug_assign<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    target: &'b Expression,
-    op: &'b Operator,
-    value: &'b Expression,
-) -> Result<(), String> {
-    let left = infer_expr(ctx, target)?.ok_or_else(|| "no value".to_string())?;
-    let right = infer_expr(ctx, value)?.ok_or_else(|| "no value".to_string())?;
-    let fun = binop_assign_name(op);
-    resolve_call(ctx, Some(left), fun, &[right])?;
-    Ok(())
-}
-
-fn check_if<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    test: &'b Expression,
-    body: &'b [Statement],
-    orelse: &'b Option<Suite>,
-) -> Result<bool, String> {
-    let boolean = ctx.get_primitive(BOOL_TYPE);
-    let t = infer_expr(ctx, test)?;
-    if t == Some(boolean) {
-        let (names, result) = ctx.with_scope(|ctx| check_stmts(ctx, body));
-        let returned = result?;
-        if let Some(orelse) = orelse {
-            let (names2, result) = ctx.with_scope(|ctx| check_stmts(ctx, orelse.as_slice()));
-            let returned = returned && result?;
-            for (name, ty) in names.iter() {
-                for (name2, ty2) in names2.iter() {
-                    if *name == *name2 && ty == ty2 {
-                        ctx.assign(name, ty.clone()).unwrap();
-                    }
-                }
-            }
-            Ok(returned)
-        } else {
-            Ok(false)
-        }
-    } else {
-        Err("condition should be bool".to_string())
-    }
-}
-
-fn check_while_stmt<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    test: &'b Expression,
-    body: &'b [Statement],
-    orelse: &'b Option<Suite>,
-) -> Result<bool, String> {
-    let boolean = ctx.get_primitive(BOOL_TYPE);
-    let t = infer_expr(ctx, test)?;
-    if t == Some(boolean) {
-        // to check what variables are defined, we would have to do a graph analysis...
-        // not implemented now
-        let (_, result) = ctx.with_scope(|ctx| check_stmts(ctx, body));
-        result?;
-        if let Some(orelse) = orelse {
-            let (_, result) = ctx.with_scope(|ctx| check_stmts(ctx, orelse.as_slice()));
-            result?;
-        }
-        // to check whether the loop returned on every possible path, we need to analyse the graph,
-        // not implemented now
-        Ok(false)
-    } else {
-        Err("condition should be bool".to_string())
-    }
-}
-
-fn check_for_stmt<'b: 'a, 'a>(
-    ctx: &mut InferenceContext<'a>,
-    target: &'b Expression,
-    iter: &'b Expression,
-    body: &'b [Statement],
-    orelse: &'b Option<Suite>,
-) -> Result<bool, String> {
-    let ty = infer_expr(ctx, iter)?.ok_or_else(|| "no value".to_string())?;
-    if let ParametricType(LIST_TYPE, ls) = ty.as_ref() {
-        let (_, result) = ctx.with_scope(|ctx| {
-            infer_simple_binding(ctx, target, ls[0].clone())?;
-            check_stmts(ctx, body)
-        });
-        result?;
-        if let Some(orelse) = orelse {
-            let (_, result) = ctx.with_scope(|ctx| check_stmts(ctx, orelse.as_slice()));
-            result?;
-        }
-        // to check whether the loop returned on every possible path, we need to analyse the graph,
-        // not implemented now
-        Ok(false)
-    } else {
-        Err("only list can be iterated over".to_string())
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::{super::context::*, *};
-    use indoc::indoc;
-    use rustpython_parser::parser::parse_program;
-
-    fn get_inference_context(ctx: TopLevelContext) -> InferenceContext {
-        InferenceContext::new(ctx, Box::new(|_| Err("unbounded identifier".into())))
-    }
-
-    #[test]
-    fn test_assign() {
-        let ctx = basic_ctx();
-        let mut ctx = get_inference_context(ctx);
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = a * 2
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = b * 2
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("unbounded identifier".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-
-        let ast = parse_program(indoc! {"
-            b = a = 1
-            b = b * 2
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            b = a = 1
-            b = [a]
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("conflicting type".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-    }
-
-    #[test]
-    fn test_if() {
-        let ctx = basic_ctx();
-        let mut ctx = get_inference_context(ctx);
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = a * 2
-            if b > a:
-                c = 1
-            else:
-                c = 0
-            d = c
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = a * 2
-            if b > a:
-                c = 1
-            else:
-                d = 0
-            d = c
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("unbounded identifier".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = a * 2
-            if b > a:
-                c = 1
-            d = c
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("unbounded identifier".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = a * 2
-            if a:
-                b = 0
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("condition should be bool".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = a * 2
-            if b > a:
-                c = 1
-            c = [1]
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = a * 2
-            if b > a:
-                c = 1
-            else:
-                c = 0
-            c = [1]
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("conflicting type".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-    }
-
-    #[test]
-    fn test_while() {
-        let ctx = basic_ctx();
-        let mut ctx = get_inference_context(ctx);
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = 1
-            while a < 10:
-                a += 1
-                b *= a
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = 1
-            while a < 10:
-                a += 1
-                b *= a
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = 1
-            while a < 10:
-                a += 1
-                b *= a
-            else:
-                a += 1
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = 1
-            while a:
-                a += 1
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("condition should be bool".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-
-        let ast = parse_program(indoc! {"
-            a = 1
-            b = 1
-            while a < 10:
-                a += 1
-                c = a*2
-            else:
-                c = a*2
-            b = c
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("unbounded identifier".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-    }
-
-    #[test]
-    fn test_for() {
-        let ctx = basic_ctx();
-        let mut ctx = get_inference_context(ctx);
-
-        let ast = parse_program(indoc! {"
-            b = 1
-            for a in [0, 1, 2, 3, 4, 5]:
-                b *= a
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            b = 1
-            for a, a1 in [(0, 1), (2, 3), (4, 5)]:
-                b *= a
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-    }
-
-    #[test]
-    fn test_return() {
-        let ctx = basic_ctx();
-        let mut ctx = get_inference_context(ctx);
-
-        let ast = parse_program(indoc! {"
-            b = 1
-            return
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(true), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            b = 1
-            if b > 0:
-                return
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            b = 1
-            if b > 0:
-                return
-            else:
-                return
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(true), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        let ast = parse_program(indoc! {"
-            b = 1
-            while b > 0:
-                return
-            else:
-                return
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            // with sophisticated analysis, this one should be Ok(true)
-            // but with our simple implementation, this is Ok(false)
-            // as we don't analyse the control flow
-            assert_eq!(Ok(false), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        ctx.set_result(Some(ctx.get_primitive(INT32_TYPE)));
-        let ast = parse_program(indoc! {"
-            b = 1
-            return 1
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(Ok(true), check_stmts(ctx, ast.statements.as_slice()));
-        });
-
-        ctx.set_result(Some(ctx.get_primitive(INT32_TYPE)));
-        let ast = parse_program(indoc! {"
-            b = 1
-            return [1]
-        " })
-        .unwrap();
-        ctx.with_scope(|ctx| {
-            assert_eq!(
-                Err("return type mismatch".to_string()),
-                check_stmts(ctx, ast.statements.as_slice())
-            );
-        });
-    }
-}

nac3core/src/type_check/typedef.rs

@@ -1,60 +0,0 @@
-use std::collections::HashMap;
-use std::rc::Rc;
-
-#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
-pub struct PrimitiveId(pub(crate) usize);
-
-#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
-pub struct ClassId(pub(crate) usize);
-
-#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
-pub struct ParamId(pub(crate) usize);
-
-#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
-pub struct VariableId(pub(crate) usize);
-
-#[derive(PartialEq, Eq, Clone, Hash, Debug)]
-pub enum TypeEnum {
-    BotType,
-    SelfType,
-    PrimitiveType(PrimitiveId),
-    ClassType(ClassId),
-    VirtualClassType(ClassId),
-    ParametricType(ParamId, Vec<Rc<TypeEnum>>),
-    TypeVariable(VariableId),
-}
-
-pub type Type = Rc<TypeEnum>;
-
-#[derive(Clone)]
-pub struct FnDef {
-    // we assume methods first argument to be SelfType,
-    // so the first argument is not contained here
-    pub args: Vec<Type>,
-    pub result: Option<Type>,
-}
-
-#[derive(Clone)]
-pub struct TypeDef<'a> {
-    pub name: &'a str,
-    pub fields: HashMap<&'a str, Type>,
-    pub methods: HashMap<&'a str, FnDef>,
-}
-
-#[derive(Clone)]
-pub struct ClassDef<'a> {
-    pub base: TypeDef<'a>,
-    pub parents: Vec<ClassId>,
-}
-
-#[derive(Clone)]
-pub struct ParametricDef<'a> {
-    pub base: TypeDef<'a>,
-    pub params: Vec<VariableId>,
-}
-
-#[derive(Clone)]
-pub struct VarDef<'a> {
-    pub name: &'a str,
-    pub bound: Vec<Type>,
-}

nac3core/src/typedef.rs

@@ -0,0 +1,223 @@
+use std::collections::HashMap;
+use std::rc::Rc;
+
+#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
+pub struct PrimitiveId(pub(crate) usize);
+
+#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
+pub struct ClassId(pub(crate) usize);
+
+#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
+pub struct ParamId(pub(crate) usize);
+
+#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
+pub struct VariableId(pub(crate) usize);
+
+#[derive(PartialEq, Eq, Clone, Hash, Debug)]
+pub enum Type {
+    BotType,
+    SelfType,
+    PrimitiveType(PrimitiveId),
+    ClassType(ClassId),
+    VirtualClassType(ClassId),
+    ParametricType(ParamId, Vec<Rc<Type>>),
+    TypeVariable(VariableId),
+}
+
+#[derive(Clone)]
+pub struct FnDef {
+    // we assume methods first argument to be SelfType,
+    // so the first argument is not contained here
+    pub args: Vec<Rc<Type>>,
+    pub result: Option<Rc<Type>>,
+}
+
+#[derive(Clone)]
+pub struct TypeDef<'a> {
+    pub name: &'a str,
+    pub fields: HashMap<&'a str, Rc<Type>>,
+    pub methods: HashMap<&'a str, FnDef>,
+}
+
+#[derive(Clone)]
+pub struct ClassDef<'a> {
+    pub base: TypeDef<'a>,
+    pub parents: Vec<ClassId>,
+}
+
+#[derive(Clone)]
+pub struct ParametricDef<'a> {
+    pub base: TypeDef<'a>,
+    pub params: Vec<VariableId>,
+}
+
+#[derive(Clone)]
+pub struct VarDef<'a> {
+    pub name: &'a str,
+    pub bound: Vec<Rc<Type>>,
+}
+
+pub struct GlobalContext<'a> {
+    primitive_defs: Vec<TypeDef<'a>>,
+    class_defs: Vec<ClassDef<'a>>,
+    parametric_defs: Vec<ParametricDef<'a>>,
+    var_defs: Vec<VarDef<'a>>,
+    sym_table: HashMap<&'a str, Type>,
+    fn_table: HashMap<&'a str, FnDef>,
+}
+
+impl<'a> GlobalContext<'a> {
+    pub fn new(primitives: Vec<TypeDef<'a>>) -> GlobalContext {
+        let mut sym_table = HashMap::new();
+        for (i, t) in primitives.iter().enumerate() {
+            sym_table.insert(t.name, Type::PrimitiveType(PrimitiveId(i)));
+        }
+        return GlobalContext {
+            primitive_defs: primitives,
+            class_defs: Vec::new(),
+            parametric_defs: Vec::new(),
+            var_defs: Vec::new(),
+            fn_table: HashMap::new(),
+            sym_table,
+        };
+    }
+
+    pub fn add_class(&mut self, def: ClassDef<'a>) -> ClassId {
+        self.sym_table.insert(
+            def.base.name,
+            Type::ClassType(ClassId(self.class_defs.len())),
+        );
+        self.class_defs.push(def);
+        ClassId(self.class_defs.len() - 1)
+    }
+
+    pub fn add_parametric(&mut self, def: ParametricDef<'a>) -> ParamId {
+        let params = def
+            .params
+            .iter()
+            .map(|&v| Rc::new(Type::TypeVariable(v)))
+            .collect();
+        self.sym_table.insert(
+            def.base.name,
+            Type::ParametricType(ParamId(self.parametric_defs.len()), params),
+        );
+        self.parametric_defs.push(def);
+        ParamId(self.parametric_defs.len() - 1)
+    }
+
+    pub fn add_variable(&mut self, def: VarDef<'a>) -> VariableId {
+        self.sym_table.insert(
+            def.name,
+            Type::TypeVariable(VariableId(self.var_defs.len())),
+        );
+        self.add_variable_private(def)
+    }
+
+    pub fn add_variable_private(&mut self, def: VarDef<'a>) -> VariableId {
+        self.var_defs.push(def);
+        VariableId(self.var_defs.len() - 1)
+    }
+
+    pub fn add_fn(&mut self, name: &'a str, def: FnDef) {
+        self.fn_table.insert(name, def);
+    }
+
+    pub fn get_fn(&self, name: &str) -> Option<&FnDef> {
+        self.fn_table.get(name)
+    }
+
+    pub fn get_primitive_mut(&mut self, id: PrimitiveId) -> &mut TypeDef<'a> {
+        self.primitive_defs.get_mut(id.0).unwrap()
+    }
+
+    pub fn get_primitive(&self, id: PrimitiveId) -> &TypeDef {
+        self.primitive_defs.get(id.0).unwrap()
+    }
+
+    pub fn get_class_mut(&mut self, id: ClassId) -> &mut ClassDef<'a> {
+        self.class_defs.get_mut(id.0).unwrap()
+    }
+
+    pub fn get_class(&self, id: ClassId) -> &ClassDef {
+        self.class_defs.get(id.0).unwrap()
+    }
+
+    pub fn get_parametric_mut(&mut self, id: ParamId) -> &mut ParametricDef<'a> {
+        self.parametric_defs.get_mut(id.0).unwrap()
+    }
+
+    pub fn get_parametric(&self, id: ParamId) -> &ParametricDef {
+        self.parametric_defs.get(id.0).unwrap()
+    }
+
+    pub fn get_variable_mut(&mut self, id: VariableId) -> &mut VarDef<'a> {
+        self.var_defs.get_mut(id.0).unwrap()
+    }
+
+    pub fn get_variable(&self, id: VariableId) -> &VarDef {
+        self.var_defs.get(id.0).unwrap()
+    }
+
+    pub fn get_type(&self, name: &str) -> Option<Type> {
+        // TODO: change this to handle import
+        self.sym_table.get(name).map(|v| v.clone())
+    }
+}
+
+impl Type {
+    pub fn subst(&self, map: &HashMap<VariableId, Rc<Type>>) -> Type {
+        match self {
+            Type::TypeVariable(id) => map.get(id).map(|v| v.as_ref()).unwrap_or(self).clone(),
+            Type::ParametricType(id, params) => Type::ParametricType(
+                *id,
+                params
+                    .iter()
+                    .map(|v| v.as_ref().subst(map).into())
+                    .collect(),
+            ),
+            _ => self.clone(),
+        }
+    }
+
+    pub fn inv_subst(&self, map: &[(Rc<Type>, Rc<Type>)]) -> Rc<Type> {
+        for (from, to) in map.iter() {
+            if self == from.as_ref() {
+                return to.clone();
+            }
+        }
+        match self {
+            Type::ParametricType(id, params) => Type::ParametricType(
+                *id,
+                params
+                    .iter()
+                    .map(|v| v.as_ref().inv_subst(map).into())
+                    .collect(),
+            ),
+            _ => self.clone(),
+        }
+        .into()
+    }
+
+    pub fn get_subst(&self, ctx: &GlobalContext) -> HashMap<VariableId, Rc<Type>> {
+        match self {
+            Type::ParametricType(id, params) => {
+                let vars = &ctx.get_parametric(*id).params;
+                vars.iter()
+                    .zip(params)
+                    .map(|(v, p)| (*v, p.as_ref().clone().into()))
+                    .collect()
+            }
+            // if this proves to be slow, we can use option type
+            _ => HashMap::new(),
+        }
+    }
+
+    pub fn get_base<'b: 'a, 'a>(&'a self, ctx: &'b GlobalContext) -> Option<&'b TypeDef> {
+        match self {
+            Type::PrimitiveType(id) => Some(ctx.get_primitive(*id)),
+            Type::ClassType(id) | Type::VirtualClassType(id) => Some(&ctx.get_class(*id).base),
+            Type::ParametricType(id, _) => Some(&ctx.get_parametric(*id).base),
+            _ => None,
+        }
+    }
+}

shell.nix

@@ -4,6 +4,6 @@ in
   pkgs.stdenv.mkDerivation {
     name = "nac3-env";
     buildInputs = with pkgs; [
-      llvm_10 clang_10 cargo rustc libffi libxml2 clippy
+      llvm_10 clang_10 cargo rustc libffi libxml2
     ];
   }

todo.txt

@@ -1,34 +0,0 @@
-Errors:
-- Not supported
-- Only * is supported
-- Expected * in *, but got *
-- Divergent type in (construct), (location 1), (location 2)
-- Unknown field
-- Unbounded variable
-- Different variable
-- Different domain
-- * is not subclass of *
-- Type not equal
-- Incorrect number of parameters
-
-Symbol Resolution:
-- Add all files with annotated class/functions.
-- Find class references, load them all in TopLevelContext.
-- Find unbounded identifiers in the functions.
-    - If it is a function/class name, record its object ID.
-    - Otherwise, load its value. (check to see if specified with `global`)
-      (Function implemented in python, with rust binding to add value to global
-       variable dictionary)
-
-Global variable dictionary:
-- Primitives, including integers, floats, bools, etc.
-- Primitive lists.
-- Numpy multi-dimensional array, with value + dimension vectors.
-- Reference array, with integer index referring to other things.
-- Symbol table: python id -> reference id.
-
-TopLevelContext/InferenceContext:
-- Restrict visibility by user defined function.
-
-
-