From 8f2936bafdfa022bddbe9b588a05c4f1592c3bd0 Mon Sep 17 00:00:00 2001
From: Shunsuke Shibayama <sbym1346@gmail.com>
Date: Fri, 15 Nov 2024 00:59:55 +0900
Subject: [PATCH] fix: intersection type bug

---
 crates/erg_compiler/context/compare.rs             |  2 +-
 crates/erg_compiler/context/generalize.rs          | 14 --------------
 crates/erg_compiler/context/hint.rs                |  9 +++++++++
 .../erg_compiler/context/initialize/const_func.rs  |  7 +++++--
 4 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/crates/erg_compiler/context/compare.rs b/crates/erg_compiler/context/compare.rs
index a6b0ce947..1a73a3e51 100644
--- a/crates/erg_compiler/context/compare.rs
+++ b/crates/erg_compiler/context/compare.rs
@@ -877,7 +877,7 @@ impl Context {
                 }
                 if l.len() == r.len() {
                     let mut r = r.clone();
-                    for _ in 1..l.len() {
+                    for _ in 0..r.len() {
                         if l.iter().zip(&r).all(|(l, r)| self.supertype_of(l, r)) {
                             return true;
                         }
diff --git a/crates/erg_compiler/context/generalize.rs b/crates/erg_compiler/context/generalize.rs
index 76284ced4..f764d28e8 100644
--- a/crates/erg_compiler/context/generalize.rs
+++ b/crates/erg_compiler/context/generalize.rs
@@ -1401,27 +1401,13 @@ impl Context {
     /// This is needed because the trait implementation spec can contain projection types.
     /// e.g. `Tuple(Ts) <: Container(Ts.union())`
     fn poly_class_trait_impl_exists(&self, class: &Type, trait_: &Type) -> bool {
-        let class_hash = get_hash(&class);
-        let trait_hash = get_hash(&trait_);
         for imp in self.get_trait_impls(trait_).into_iter() {
             let _sub_subs = Substituter::substitute_typarams(self, &imp.sub_type, class).ok();
             let _sup_subs = Substituter::substitute_typarams(self, &imp.sup_trait, trait_).ok();
             if self.supertype_of(&imp.sub_type, class) && self.supertype_of(&imp.sup_trait, trait_)
             {
-                if class_hash != get_hash(&class) {
-                    class.undo();
-                }
-                if trait_hash != get_hash(&trait_) {
-                    trait_.undo();
-                }
                 return true;
             }
-            if class_hash != get_hash(&class) {
-                class.undo();
-            }
-            if trait_hash != get_hash(&trait_) {
-                trait_.undo();
-            }
         }
         false
     }
diff --git a/crates/erg_compiler/context/hint.rs b/crates/erg_compiler/context/hint.rs
index a45a7b098..c429ead44 100644
--- a/crates/erg_compiler/context/hint.rs
+++ b/crates/erg_compiler/context/hint.rs
@@ -44,6 +44,9 @@ impl Context {
         expected: &Type,
         found: &Type,
     ) -> Option<String> {
+        if self.cfg.fast_error_report {
+            return None;
+        }
         if &callee_t.qual_name()[..] == "List" && attr == Some("__getitem__") && nth == 1 {
             let len = &callee_t.typarams().get(1).cloned()?;
             let (_, _, pred) = found.clone().deconstruct_refinement().ok()?;
@@ -73,6 +76,9 @@ impl Context {
         expected: &Type,
         found: &Type,
     ) -> Option<String> {
+        if self.cfg.fast_error_report {
+            return None;
+        }
         let expected = if let Some(fv) = expected.as_free() {
             if fv.is_linked() {
                 fv.crack().clone()
@@ -284,6 +290,9 @@ impl Context {
     }
 
     pub(crate) fn get_no_candidate_hint(&self, proj: &Type) -> Option<String> {
+        if self.cfg.fast_error_report {
+            return None;
+        }
         match proj {
             Type::Proj { lhs, rhs: _ } => {
                 if let Some(fv) = lhs.as_free() {
diff --git a/crates/erg_compiler/context/initialize/const_func.rs b/crates/erg_compiler/context/initialize/const_func.rs
index 60881fd79..30d66589d 100644
--- a/crates/erg_compiler/context/initialize/const_func.rs
+++ b/crates/erg_compiler/context/initialize/const_func.rs
@@ -243,9 +243,12 @@ pub(crate) fn sub_vdict_get<'d>(
         if key == k {
             return Some(v);
         }
-        match (ctx.convert_value_into_type(key.clone()), ctx.convert_value_into_type(k.clone())) {
+        match (
+            ctx.convert_value_into_type(key.clone()),
+            ctx.convert_value_into_type(k.clone()),
+        ) {
             (Ok(idx), Ok(kt))
-                if ctx.subtype_of(&idx.lower_bounded(), &kt.lower_bounded()) /*|| dict.len() == 1*/ =>
+                if dict.len() == 1 || ctx.subtype_of(&idx.lower_bounded(), &kt.lower_bounded()) =>
             {
                 matches.push((idx, kt, v));
             }