function call implementation

nac3core/src/typecheck/symbol_resolver.rs

@@ -1,5 +1,6 @@
 use super::typedef::Type;
 use super::location::Location;
+use rustpython_parser::ast::Expr;
 
 pub enum SymbolType {
     TypeName(Type),
@@ -16,7 +17,8 @@ pub enum SymbolValue<'a> {
 }
 
 pub trait SymbolResolver {
-    fn get_symbol_type(&mut self, str: &str) -> Option<SymbolType>;
+    fn get_symbol_type(&mut self, str: &str) -> Option<Type>;
+    fn parse_type_name(&mut self, expr: &Expr<()>) -> Option<Type>;
     fn get_symbol_value(&mut self, str: &str) -> Option<SymbolValue>;
     fn get_symbol_location(&mut self, str: &str) -> Option<Location>;
     // handle function call etc.

nac3core/src/typecheck/type_inferencer.rs

@@ -5,7 +5,7 @@ use std::iter::once;
 use std::rc::Rc;
 
 use super::magic_methods::*;
-use super::symbol_resolver::{SymbolResolver, SymbolType};
+use super::symbol_resolver::SymbolResolver;
 use super::typedef::{Call, FunSignature, FuncArg, Type, TypeEnum, Unifier};
 use itertools::izip;
 use rustpython_parser::ast::{
@@ -44,7 +44,7 @@ impl<'a> fold::Fold<()> for Inferencer<'a> {
                 func,
                 args,
                 keywords,
-            } => unimplemented!(),
+            } => self.fold_call(node.location, *func, args, keywords)?,
             ast::ExprKind::Lambda { args, body } => {
                 self.fold_lambda(node.location, *args, *body)?
             }
@@ -71,14 +71,15 @@ impl<'a> fold::Fold<()> for Inferencer<'a> {
                 ops,
                 comparators,
             } => Some(self.infer_compare(left, ops, comparators)?),
-            ast::ExprKind::Call { .. } => expr.custom,
             ast::ExprKind::Subscript { value, slice, .. } => {
                 Some(self.infer_subscript(value.as_ref(), slice.as_ref())?)
             }
             ast::ExprKind::IfExp { test, body, orelse } => {
                 Some(self.infer_if_expr(test, body.as_ref(), orelse.as_ref())?)
             }
-            ast::ExprKind::ListComp { .. } | ast::ExprKind::Lambda { .. } => expr.custom, // already computed
+            ast::ExprKind::ListComp { .. }
+            | ast::ExprKind::Lambda { .. }
+            | ast::ExprKind::Call { .. } => expr.custom, // already computed
             ast::ExprKind::Slice { .. } => None, // we don't need it for slice
             _ => return Err("not supported yet".into()),
         };
@@ -243,21 +244,127 @@ impl<'a> Inferencer<'a> {
         })
     }
 
+    fn fold_call(
+        &mut self,
+        location: Location,
+        func: ast::Expr<()>,
+        mut args: Vec<ast::Expr<()>>,
+        keywords: Vec<Located<ast::KeywordData>>,
+    ) -> Result<ast::Expr<Option<Type>>, String> {
+        let func = if let Located {
+            location: func_location,
+            custom,
+            node: ExprKind::Name { id, ctx },
+        } = func
+        {
+            // handle special functions that cannot be typed in the usual way...
+            if id == "virtual" {
+                if args.is_empty() || args.len() > 2 || !keywords.is_empty() {
+                    return Err("`virtual` can only accept 1/2 positional arguments.".to_string());
+                }
+                let arg0 = self.fold_expr(args.remove(0))?;
+                let ty = if let Some(arg) = args.pop() {
+                    self.resolver
+                        .parse_type_name(&arg)
+                        .ok_or_else(|| "error parsing type".to_string())?
+                } else {
+                    self.unifier.get_fresh_var().0
+                };
+                let custom = Some(self.unifier.add_ty(TypeEnum::TVirtual { ty }));
+                return Ok(Located {
+                    location,
+                    custom,
+                    node: ExprKind::Call {
+                        func: Box::new(Located {
+                            custom: None,
+                            location: func.location,
+                            node: ExprKind::Name { id, ctx },
+                        }),
+                        args: vec![arg0],
+                        keywords: vec![],
+                    },
+                });
+            }
+            // int64 is special because its argument can be a constant larger than int32
+            if id == "int64" && args.len() == 1 {
+                if let ExprKind::Constant {
+                    value: ast::Constant::Int(val),
+                    ..
+                } = &args[0].node
+                {
+                    let int64: Result<i64, _> = val.try_into();
+                    let custom;
+                    if int64.is_ok() {
+                        custom = Some(self.primitives.int64);
+                    } else {
+                        return Err("Integer out of bound".into());
+                    }
+                    return Ok(Located {
+                        location,
+                        custom,
+                        node: ExprKind::Call {
+                            func: Box::new(Located {
+                                custom: None,
+                                location: func.location,
+                                node: ExprKind::Name { id, ctx },
+                            }),
+                            args: vec![self.fold_expr(args.pop().unwrap())?],
+                            keywords: vec![],
+                        },
+                    });
+                }
+            }
+            Located {
+                location: func_location,
+                custom,
+                node: ExprKind::Name { id, ctx },
+            }
+        } else {
+            func
+        };
+        let func = Box::new(self.fold_expr(func)?);
+        let args = args
+            .into_iter()
+            .map(|v| self.fold_expr(v))
+            .collect::<Result<Vec<_>, _>>()?;
+        let keywords = keywords
+            .into_iter()
+            .map(|v| fold::fold_keyword(self, v))
+            .collect::<Result<Vec<_>, _>>()?;
+        let ret = self.unifier.get_fresh_var().0;
+        let call = Rc::new(Call {
+            posargs: args.iter().map(|v| v.custom.unwrap()).collect(),
+            kwargs: keywords
+                .iter()
+                .map(|v| (v.node.arg.as_ref().unwrap().clone(), v.custom.unwrap()))
+                .collect(),
+            fun: RefCell::new(None),
+            ret,
+        });
+        self.calls.push(call.clone());
+        let call = self.unifier.add_ty(TypeEnum::TCall { calls: vec![call] });
+        self.unifier.unify(func.custom.unwrap(), call)?;
+
+        Ok(Located {
+            location,
+            custom: Some(ret),
+            node: ExprKind::Call {
+                func,
+                args,
+                keywords,
+            },
+        })
+    }
+
     fn infer_identifier(&mut self, id: &str) -> InferenceResult {
         if let Some(ty) = self.variable_mapping.get(id) {
             Ok(*ty)
         } else {
-            match self.resolver.get_symbol_type(id) {
-                Some(SymbolType::TypeName(_)) => {
-                    Err("Expected expression instead of type".to_string())
-                }
-                Some(SymbolType::Identifier(ty)) => Ok(ty),
-                None => {
-                    let ty = self.unifier.get_fresh_var().0;
-                    self.variable_mapping.insert(id.to_string(), ty);
-                    Ok(ty)
-                }
-            }
+            Ok(self.resolver.get_symbol_type(id).unwrap_or_else(|| {
+                let ty = self.unifier.get_fresh_var().0;
+                self.variable_mapping.insert(id.to_string(), ty);
+                ty
+            }))
         }
     }
 
@@ -268,7 +375,7 @@ impl<'a> Inferencer<'a> {
                 let int32: Result<i32, _> = val.try_into();
                 // int64 would be handled separately in functions
                 if int32.is_ok() {
-                    Ok(self.primitives.int64)
+                    Ok(self.primitives.int32)
                 } else {
                     Err("Integer out of bound".into())
                 }