From 60f1e4519eb9ac4b96271267d7f7bcfc554b6b9f Mon Sep 17 00:00:00 2001
From: Sam Vervaeck <samvv@pm.me>
Date: Mon, 19 Feb 2024 14:17:12 +0100
Subject: [PATCH] Fix #54: BindPattern is not bound during inference inside a
 match-expression

---
 bootstrap/cxx/include/bolt/CST.hpp | 11 +++++++++++
 bootstrap/cxx/src/CST.cc           |  6 ++++++
 bootstrap/cxx/src/Checker.cc       |  4 ++--
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/bootstrap/cxx/include/bolt/CST.hpp b/bootstrap/cxx/include/bolt/CST.hpp
index ad0c0e02d..06feeae6e 100644
--- a/bootstrap/cxx/include/bolt/CST.hpp
+++ b/bootstrap/cxx/include/bolt/CST.hpp
@@ -1637,6 +1637,9 @@ namespace bolt {
   };
 
   class MatchCase : public Node { 
+
+    Scope* TheScope = nullptr;
+
   public:
 
     InferContext* Ctx;
@@ -1657,6 +1660,14 @@ namespace bolt {
     Token* getFirstToken() const override;
     Token* getLastToken() const override;
 
+    inline Scope* getScope() override {
+      if (TheScope == nullptr) {
+        TheScope = new Scope(this);
+      }
+      return TheScope;
+    }
+
+
   };
 
   class MatchExpression : public Expression {
diff --git a/bootstrap/cxx/src/CST.cc b/bootstrap/cxx/src/CST.cc
index ffaa0f5cb..82643d7b9 100644
--- a/bootstrap/cxx/src/CST.cc
+++ b/bootstrap/cxx/src/CST.cc
@@ -78,6 +78,12 @@ namespace bolt {
         }
         break;
       }
+      case NodeKind::MatchCase:
+      {
+        auto Case = static_cast<MatchCase*>(X);
+        visitPattern(Case->Pattern, Case);
+        break;
+      }
       case NodeKind::LetDeclaration:
       {
         auto Decl = static_cast<LetDeclaration*>(X);
diff --git a/bootstrap/cxx/src/Checker.cc b/bootstrap/cxx/src/Checker.cc
index eee54574c..a0ef8e2c2 100644
--- a/bootstrap/cxx/src/Checker.cc
+++ b/bootstrap/cxx/src/Checker.cc
@@ -508,6 +508,7 @@ namespace bolt {
 
       auto Instance = static_cast<InstanceDeclaration*>(Let->Parent);
       auto Class = cast<ClassDeclaration>(Instance->getScope()->lookup({ {}, getCanonicalText(Instance->Name) }, SymbolKind::Class));
+      // TODO check if `Class` is nullptr
       auto SigLet = cast<LetDeclaration>(Class->getScope()->lookupDirect({ {}, Let->getNameAsString() }, SymbolKind::Var));
 
       auto Params = addClassVars(Class, false);
@@ -1297,7 +1298,7 @@ namespace bolt {
         auto Y = static_cast<ReferenceExpression*>(N);
         auto Def = Y->getScope()->lookup(Y->getSymbolPath());
         // Name lookup failures will be reported directly in inferExpression().
-        if (Def == nullptr || Def->getKind() == NodeKind::SourceFile) {
+        if (Def == nullptr || Def->getKind() != NodeKind::LetDeclaration) {
           return;
         }
         // This case ensures that a deeply nested structure that references a
@@ -1307,7 +1308,6 @@ namespace bolt {
           RefGraph.addEdge(Stack.top(), Def->Parent);
           return;
         }
-        ZEN_ASSERT(Def->getKind() == NodeKind::LetDeclaration);
         if (!Stack.empty()) {
           RefGraph.addEdge(Def, Stack.top());
         }