From 5ed2b450d39bc416dd65198fd30e8afa1f66c677 Mon Sep 17 00:00:00 2001
From: pca006132 <john.lck40@gmail.com>
Date: Wed, 22 Sep 2021 15:43:44 +0800
Subject: [PATCH] nac3core/typecheck: no type variable for monomorphic
 functions

---
 nac3core/src/typecheck/type_inferencer/mod.rs | 52 ++++++++++++++++---
 1 file changed, 46 insertions(+), 6 deletions(-)

diff --git a/nac3core/src/typecheck/type_inferencer/mod.rs b/nac3core/src/typecheck/type_inferencer/mod.rs
index 8c1f68be9..f6a61293b 100644
--- a/nac3core/src/typecheck/type_inferencer/mod.rs
+++ b/nac3core/src/typecheck/type_inferencer/mod.rs
@@ -238,8 +238,32 @@ impl<'a> Inferencer<'a> {
         method: String,
         obj: Type,
         params: Vec<Type>,
-        ret: Type,
+        ret: Option<Type>,
     ) -> InferenceResult {
+        if let TypeEnum::TObj { params: class_params, fields, .. } = &*self.unifier.get_ty(obj) {
+            if class_params.borrow().is_empty() {
+                if let Some(ty) = fields.borrow().get(&method) {
+                    if let TypeEnum::TFunc(sign) = &*self.unifier.get_ty(*ty) {
+                        let sign = sign.borrow();
+                        if sign.vars.is_empty() {
+                            let call = self.unifier.add_call(Call {
+                                posargs: params,
+                                kwargs: HashMap::new(),
+                                fun: RefCell::new(Some(*ty)),
+                                ret: sign.ret,
+                            });
+                            if let Some(ret) = ret {
+                                self.unifier.unify(sign.ret, ret).unwrap();
+                            }
+                            self.calls.insert(location.into(), call);
+                            return Ok(sign.ret)
+                        }
+                    }
+                }
+            }
+        }
+        let ret = ret.unwrap_or_else(|| self.unifier.get_fresh_var().0);
+
         let call = self.unifier.add_call(Call {
             posargs: params,
             kwargs: HashMap::new(),
@@ -460,6 +484,24 @@ impl<'a> Inferencer<'a> {
             .into_iter()
             .map(|v| fold::fold_keyword(self, v))
             .collect::<Result<Vec<_>, _>>()?;
+
+        if let TypeEnum::TFunc(sign) = &*self.unifier.get_ty(func.custom.unwrap()) {
+            let sign = sign.borrow();
+            if sign.vars.is_empty() {
+                let call = self.unifier.add_call(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(func.custom),
+                    ret: sign.ret,
+                });
+                self.calls.insert(location.into(), call);
+                return Ok(Located { location, custom: Some(sign.ret), node: ExprKind::Call { func, args, keywords } })
+            }
+        }
+
         let ret = self.unifier.get_fresh_var().0;
         let call = self.unifier.add_call(Call {
             posargs: args.iter().map(|v| v.custom.unwrap()).collect(),
@@ -553,13 +595,12 @@ impl<'a> Inferencer<'a> {
         right: &ast::Expr<Option<Type>>,
     ) -> InferenceResult {
         let method = binop_name(op);
-        let ret = self.unifier.get_fresh_var().0;
         self.build_method_call(
             location,
             method.to_string(),
             left.custom.unwrap(),
             vec![right.custom.unwrap()],
-            ret,
+            None,
         )
     }
 
@@ -569,13 +610,12 @@ impl<'a> Inferencer<'a> {
         operand: &ast::Expr<Option<Type>>,
     ) -> InferenceResult {
         let method = unaryop_name(op);
-        let ret = self.unifier.get_fresh_var().0;
         self.build_method_call(
             operand.location,
             method.to_string(),
             operand.custom.unwrap(),
             vec![],
-            ret,
+            None,
         )
     }
 
@@ -594,7 +634,7 @@ impl<'a> Inferencer<'a> {
                 method,
                 a.custom.unwrap(),
                 vec![b.custom.unwrap()],
-                boolean,
+                Some(boolean),
             )?;
         }
         Ok(boolean)