updated todo

nac3core/src/inference.rs

@@ -0,0 +1,591 @@
+use super::typedef::{Type::*, *};
+use std::collections::HashMap;
+use std::rc::Rc;
+
+fn find_subst(
+    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 {
+                a = t.clone();
+            }
+        }
+    }
+
+    let mut substituted = false;
+    if let TypeVariable(id) = b.as_ref() {
+        if let Some(c) = sub.get(&id) {
+            b = c.clone();
+            substituted = true;
+        }
+    }
+
+    match (a.as_ref(), b.as_ref()) {
+        (BotType, _) => Ok(()),
+        (TypeVariable(id_a), TypeVariable(id_b)) => {
+            if substituted {
+                return if id_a == id_b {
+                    Ok(())
+                } else {
+                    Err("different variables".to_string())
+                };
+            }
+            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.len() > 0 {
+                        return Err("different domain".to_string());
+                    }
+                }
+            }
+            sub.insert(*id_b, a.clone().into());
+            Ok(())
+        }
+        (TypeVariable(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("different domain".to_string())
+            }
+        }
+        (_, TypeVariable(id_b)) => {
+            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("different domain".to_string())
+            }
+        }
+        (_, VirtualClassType(id_b)) => {
+            let mut parents;
+            match a.as_ref() {
+                ClassType(id_a) => {
+                    parents = [*id_a].to_vec();
+                }
+                VirtualClassType(id_a) => {
+                    parents = [*id_a].to_vec();
+                }
+                _ => {
+                    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(parents.remove(0));
+                parents.extend_from_slice(&c.parents);
+            }
+            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("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())?;
+                }
+                Ok(())
+            }
+        }
+        (_, _) => {
+            if a == b {
+                Ok(())
+            } else {
+                Err("not equal".to_string())
+            }
+        }
+    }
+}
+
+fn resolve_call_rec(
+    ctx: &GlobalContext,
+    valuation: &Option<(VariableId, Rc<Type>)>,
+    obj: Option<Rc<Type>>,
+    func: &str,
+    args: &[Rc<Type>],
+) -> Result<Option<Rc<Type>>, String> {
+    let mut subst = obj
+        .as_ref()
+        .map(|v| v.get_subst(ctx))
+        .unwrap_or(HashMap::new());
+
+    let fun = match &obj {
+        Some(obj) => {
+            let base = match obj.as_ref() {
+                TypeVariable(id) => {
+                    let v = ctx.get_variable(*id);
+                    if v.bound.len() == 0 {
+                        return Err("unbounded type var".to_string());
+                    }
+                    let results: Result<Vec<_>, String> = v
+                        .bound
+                        .iter()
+                        .map(|ins| {
+                            resolve_call_rec(
+                                ctx,
+                                &Some((*id, ins.clone())),
+                                Some(ins.clone()),
+                                func,
+                                args.clone(),
+                            )
+                        })
+                        .collect();
+                    let results = results?;
+                    if results.iter().all(|v| v == &results[0]) {
+                        return Ok(results[0].clone());
+                    }
+                    let mut results = results.iter().zip(v.bound.iter()).map(|(r, ins)| {
+                        r.as_ref()
+                            .map(|v| v.inv_subst(&[(ins.clone(), obj.clone().into())]))
+                    });
+                    let first = results.next().unwrap();
+                    if results.all(|v| v == first) {
+                        return Ok(first);
+                    } else {
+                        return Err("divergent type after substitution".to_string());
+                    }
+                }
+                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(func),
+    }
+    .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())?;
+    }
+    let result = fun.result.as_ref().map(|v| v.subst(&subst));
+    Ok(result.map(|result| {
+        if let SelfType = result {
+            obj.unwrap()
+        } else {
+            result.into()
+        }
+    }))
+}
+
+pub fn resolve_call(
+    ctx: &GlobalContext,
+    obj: Option<Rc<Type>>,
+    func: &str,
+    args: &[Rc<Type>],
+) -> Result<Option<Rc<Type>>, String> {
+    resolve_call_rec(ctx, &None, obj, func, args)
+}
+
+#[cfg(test)]
+mod tests {
+    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![
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
+        });
+
+        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![
+                PrimitiveType(BOOL_TYPE).into(),
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
+        });
+
+        assert_eq!(
+            resolve_call(&ctx, None, "float", &[TypeVariable(v2).into()]),
+            Err("different domain".to_string())
+        );
+    }
+
+    #[test]
+    fn test_methods() {
+        let mut ctx = basic_ctx();
+
+        let v0 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V0",
+            bound: vec![],
+        })));
+        let v1 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V1",
+            bound: vec![
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
+        })));
+        let v2 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V2",
+            bound: vec![
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
+        })));
+        let v3 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V3",
+            bound: vec![
+                PrimitiveType(BOOL_TYPE).into(),
+                PrimitiveType(INT32_TYPE).into(),
+                PrimitiveType(FLOAT_TYPE).into(),
+            ],
+        })));
+
+        let int32 = Rc::new(PrimitiveType(INT32_TYPE));
+        let int64 = Rc::new(PrimitiveType(INT64_TYPE));
+
+        // simple cases
+        assert_eq!(
+            resolve_call(&ctx, Some(int32.clone()), "__add__", &[int32.clone()]),
+            Ok(Some(int32.clone()))
+        );
+
+        assert_ne!(
+            resolve_call(&ctx, Some(int32.clone()), "__add__", &[int32.clone()]),
+            Ok(Some(int64.clone()))
+        );
+
+        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_eq!(
+            resolve_call(&ctx, Some(v0.clone()), "__add__", &[v2.clone()]),
+            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("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 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V0",
+            bound: vec![],
+        })));
+        let v1 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V1",
+            bound: vec![],
+        })));
+        let v2 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V2",
+            bound: vec![],
+        })));
+        let v3 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V3",
+            bound: vec![],
+        })));
+
+        ctx.add_fn(
+            "foo",
+            FnDef {
+                args: vec![v0.clone(), v0.clone(), v1.clone()],
+                result: Some(v0.clone()),
+            },
+        );
+
+        ctx.add_fn(
+            "foo1",
+            FnDef {
+                args: vec![
+                    ParametricType(TUPLE_TYPE, vec![v0.clone(), v0.clone(), v1.clone()]).into(),
+                ],
+                result: Some(v0.clone()),
+            },
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[v2.clone(), v2.clone(), v2.clone()]),
+            Ok(Some(v2.clone()))
+        );
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[v2.clone(), v2.clone(), v3.clone()]),
+            Ok(Some(v2.clone()))
+        );
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[v2.clone(), v3.clone(), v3.clone()]),
+            Err("different variables".to_string())
+        );
+
+        assert_eq!(
+            resolve_call(
+                &ctx,
+                None,
+                "foo1",
+                &[ParametricType(TUPLE_TYPE, vec![v2.clone(), v2.clone(), v2.clone()]).into()]
+            ),
+            Ok(Some(v2.clone()))
+        );
+        assert_eq!(
+            resolve_call(
+                &ctx,
+                None,
+                "foo1",
+                &[ParametricType(TUPLE_TYPE, vec![v2.clone(), v2.clone(), v3.clone()]).into()]
+            ),
+            Ok(Some(v2.clone()))
+        );
+        assert_eq!(
+            resolve_call(
+                &ctx,
+                None,
+                "foo1",
+                &[ParametricType(TUPLE_TYPE, vec![v2.clone(), v3.clone(), v3.clone()]).into()]
+            ),
+            Err("different variables".to_string())
+        );
+    }
+
+    #[test]
+    fn test_class_generics() {
+        let mut ctx = basic_ctx();
+
+        let list = ctx.get_parametric_mut(LIST_TYPE);
+        let t = Rc::new(TypeVariable(list.params[0]));
+        list.base.methods.insert(
+            "head",
+            FnDef {
+                args: vec![],
+                result: Some(t.clone()),
+            },
+        );
+        list.base.methods.insert(
+            "append",
+            FnDef {
+                args: vec![t.clone()],
+                result: None,
+            },
+        );
+
+        let v0 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V0",
+            bound: vec![],
+        })));
+        let v1 = Rc::new(TypeVariable(ctx.add_variable(VarDef {
+            name: "V1",
+            bound: vec![],
+        })));
+
+        assert_eq!(
+            resolve_call(
+                &ctx,
+                Some(ParametricType(LIST_TYPE, vec![v0.clone()]).into()),
+                "head",
+                &[]
+            ),
+            Ok(Some(v0.clone()))
+        );
+        assert_eq!(
+            resolve_call(
+                &ctx,
+                Some(ParametricType(LIST_TYPE, vec![v0.clone()]).into()),
+                "append",
+                &[v0.clone()]
+            ),
+            Ok(None)
+        );
+        assert_eq!(
+            resolve_call(
+                &ctx,
+                Some(ParametricType(LIST_TYPE, vec![v0.clone()]).into()),
+                "append",
+                &[v1.clone()]
+            ),
+            Err("different variables".to_string())
+        );
+    }
+
+    #[test]
+    fn test_virtual_class() {
+        let mut ctx = basic_ctx();
+
+        let foo = ctx.add_class(ClassDef {
+            base: TypeDef {
+                name: "Foo",
+                methods: HashMap::new(),
+                fields: HashMap::new(),
+            },
+            parents: vec![],
+        });
+
+        let foo1 = ctx.add_class(ClassDef {
+            base: TypeDef {
+                name: "Foo1",
+                methods: HashMap::new(),
+                fields: HashMap::new(),
+            },
+            parents: vec![foo],
+        });
+
+        let foo2 = ctx.add_class(ClassDef {
+            base: TypeDef {
+                name: "Foo2",
+                methods: HashMap::new(),
+                fields: HashMap::new(),
+            },
+            parents: vec![foo1],
+        });
+
+        let bar = ctx.add_class(ClassDef {
+            base: TypeDef {
+                name: "bar",
+                methods: HashMap::new(),
+                fields: HashMap::new(),
+            },
+            parents: vec![],
+        });
+
+        ctx.add_fn(
+            "foo",
+            FnDef {
+                args: vec![VirtualClassType(foo).into()],
+                result: None,
+            },
+        );
+        ctx.add_fn(
+            "foo1",
+            FnDef {
+                args: vec![VirtualClassType(foo1).into()],
+                result: None,
+            },
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[ClassType(foo).into()]),
+            Ok(None)
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[ClassType(foo1).into()]),
+            Ok(None)
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[ClassType(foo2).into()]),
+            Ok(None)
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[ClassType(bar).into()]),
+            Err("not subtype".to_string())
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo1", &[ClassType(foo1).into()]),
+            Ok(None)
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo1", &[ClassType(foo2).into()]),
+            Ok(None)
+        );
+
+        assert_eq!(
+            resolve_call(&ctx, None, "foo1", &[ClassType(foo).into()]),
+            Err("not subtype".to_string())
+        );
+
+        // virtual class substitution
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[VirtualClassType(foo).into()]),
+            Ok(None)
+        );
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[VirtualClassType(foo1).into()]),
+            Ok(None)
+        );
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[VirtualClassType(foo2).into()]),
+            Ok(None)
+        );
+        assert_eq!(
+            resolve_call(&ctx, None, "foo", &[VirtualClassType(bar).into()]),
+            Err("not subtype".to_string())
+        );
+    }
+}

nac3core/src/lib.rs

@@ -2,6 +2,12 @@ extern crate num_bigint;
 extern crate inkwell;
 extern crate rustpython_parser;
 
+pub mod expression;
+pub mod inference;
+mod operators;
+pub mod primitives;
+pub mod typedef;
+
 use std::error::Error;
 use std::fmt;
 use std::path::Path;

nac3core/src/operators.rs

@@ -0,0 +1,58 @@
+use rustpython_parser::ast::{Comparison, Operator, UnaryOperator};
+
+pub fn binop_name(op: &Operator) -> &'static str {
+    match op {
+        Operator::Add => "__add__",
+        Operator::Sub => "__sub__",
+        Operator::Div => "__truediv__",
+        Operator::Mod => "__mod__",
+        Operator::Mult => "__mul__",
+        Operator::Pow => "__pow__",
+        Operator::BitOr => "__or__",
+        Operator::BitXor => "__xor__",
+        Operator::BitAnd => "__and__",
+        Operator::LShift => "__lshift__",
+        Operator::RShift => "__rshift__",
+        Operator::FloorDiv => "__floordiv__",
+        Operator::MatMult => "__matmul__",
+    }
+}
+
+pub fn binop_assign_name(op: &Operator) -> &'static str {
+    match op {
+        Operator::Add => "__iadd__",
+        Operator::Sub => "__isub__",
+        Operator::Div => "__itruediv__",
+        Operator::Mod => "__imod__",
+        Operator::Mult => "__imul__",
+        Operator::Pow => "__ipow__",
+        Operator::BitOr => "__ior__",
+        Operator::BitXor => "__ixor__",
+        Operator::BitAnd => "__iand__",
+        Operator::LShift => "__ilshift__",
+        Operator::RShift => "__irshift__",
+        Operator::FloorDiv => "__ifloordiv__",
+        Operator::MatMult => "__imatmul__",
+    }
+}
+
+pub fn unaryop_name(op: &UnaryOperator) -> &'static str {
+    match op {
+        UnaryOperator::Pos => "__pos__",
+        UnaryOperator::Neg => "__neg__",
+        UnaryOperator::Not => "__not__",
+        UnaryOperator::Inv => "__inv__",
+    }
+}
+
+pub fn comparison_name(op: &Comparison) -> Option<&'static str> {
+    match op {
+        Comparison::Less => Some("__lt__"),
+        Comparison::LessOrEqual => Some("__le__"),
+        Comparison::Greater => Some("__gt__"),
+        Comparison::GreaterOrEqual => Some("__ge__"),
+        Comparison::Equal => Some("__eq__"),
+        Comparison::NotEqual => Some("__ne__"),
+        _ => None,
+    }
+}

nac3core/src/primitives.rs

@@ -0,0 +1,181 @@
+use super::typedef::{Type::*, *};
+use std::collections::HashMap;
+use std::rc::Rc;
+
+pub const TUPLE_TYPE: ParamId = ParamId(0);
+pub const LIST_TYPE: ParamId = ParamId(1);
+
+pub const BOOL_TYPE: PrimitiveId = PrimitiveId(0);
+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: &Rc<Type>) {
+    let result = Some(ty.clone());
+    let fun = FnDef {
+        args: vec![ty.clone()],
+        result: result.clone(),
+    };
+    def.methods.insert("__add__", fun.clone());
+    def.methods.insert("__sub__", fun.clone());
+    def.methods.insert("__mul__", fun.clone());
+    def.methods.insert("__neg__", FnDef {
+        args: vec![],
+        result
+    });
+    def.methods.insert(
+        "__truediv__",
+        FnDef {
+            args: vec![ty.clone()],
+            result: Some(PrimitiveType(FLOAT_TYPE).into()),
+        },
+    );
+    def.methods.insert("__floordiv__", fun.clone());
+    def.methods.insert("__mod__", fun.clone());
+    def.methods.insert("__pow__", fun.clone());
+}
+
+fn impl_bits(def: &mut TypeDef, ty: &Rc<Type>) {
+    let result = Some(ty.clone());
+    let fun = FnDef {
+        args: vec![PrimitiveType(INT32_TYPE).into()],
+        result,
+    };
+
+    def.methods.insert("__lshift__", fun.clone());
+    def.methods.insert("__rshift__", fun.clone());
+    def.methods.insert(
+        "__xor__",
+        FnDef {
+            args: vec![ty.clone()],
+            result: Some(ty.clone()),
+        },
+    );
+}
+
+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.clone());
+}
+
+fn impl_order(def: &mut TypeDef, ty: &Rc<Type>) {
+    let fun = FnDef {
+        args: vec![ty.clone()],
+        result: Some(PrimitiveType(BOOL_TYPE).into()),
+    };
+
+    def.methods.insert("__lt__", fun.clone());
+    def.methods.insert("__gt__", fun.clone());
+    def.methods.insert("__le__", fun.clone());
+    def.methods.insert("__ge__", fun.clone());
+}
+
+pub fn basic_ctx() -> GlobalContext<'static> {
+    let primitives = [
+        TypeDef {
+            name: "bool",
+            fields: HashMap::new(),
+            methods: HashMap::new(),
+        },
+        TypeDef {
+            name: "int32",
+            fields: HashMap::new(),
+            methods: HashMap::new(),
+        },
+        TypeDef {
+            name: "int64",
+            fields: HashMap::new(),
+            methods: HashMap::new(),
+        },
+        TypeDef {
+            name: "float",
+            fields: HashMap::new(),
+            methods: HashMap::new(),
+        },
+    ]
+    .to_vec();
+    let mut ctx = GlobalContext::new(primitives);
+
+    let b_def = ctx.get_primitive_mut(BOOL_TYPE);
+    let b = PrimitiveType(BOOL_TYPE).into();
+    impl_eq(b_def, &b);
+    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_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_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);
+
+    let t = ctx.add_variable_private(VarDef {
+        name: "T",
+        bound: vec![],
+    });
+
+    ctx.add_parametric(ParametricDef {
+        base: TypeDef {
+            name: "tuple",
+            fields: HashMap::new(),
+            methods: HashMap::new(),
+        },
+        // we have nothing for tuple, so no param def
+        params: vec![],
+    });
+
+    ctx.add_parametric(ParametricDef {
+        base: TypeDef {
+            name: "list",
+            fields: HashMap::new(),
+            methods: HashMap::new(),
+        },
+        params: vec![t],
+    });
+
+    let i = ctx.add_variable_private(VarDef {
+        name: "I",
+        bound: vec![
+            PrimitiveType(INT32_TYPE).into(),
+            PrimitiveType(INT64_TYPE).into(),
+            PrimitiveType(FLOAT_TYPE).into(),
+        ],
+    });
+    let args = vec![TypeVariable(i).into()];
+    ctx.add_fn(
+        "int32",
+        FnDef {
+            args: args.clone(),
+            result: Some(PrimitiveType(INT32_TYPE).into()),
+        },
+    );
+    ctx.add_fn(
+        "int64",
+        FnDef {
+            args: args.clone(),
+            result: Some(PrimitiveType(INT64_TYPE).into()),
+        },
+    );
+    ctx.add_fn(
+        "float",
+        FnDef {
+            args: args.clone(),
+            result: Some(PrimitiveType(FLOAT_TYPE).into()),
+        },
+    );
+
+    ctx
+}

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,
+        }
+    }
+}

todo.txt

@@ -0,0 +1,28 @@
+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
+
+GlobalContext:
+- Separate from typedefs
+- Interact with python intepreter to get data
+- Primitive Type Instance List
+- Symbol Table (readable, ever defined)
+- TypeVar definition stack
+- Provide subst, inv_subst, blablabla
+- Cache type var method lookup (dropped when related assumptions are changed)
+- Responsible for printing the error (lookup module/type info, handle line number offset)
+
+Name Resolution:
+- Get class/methods, track module via `inspect.getmodule`
+- GlobalContext store function/class - module association, perform name
+  resolution in the module when identifier is unbounded, and check its type
+