feat(overload): support default return types

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 6 insertions, 0 deletions

diff --git a/include/cps/FunctionAST.h b/include/cps/FunctionAST.h
index 9188015..5280d58 100644
--- a/include/cps/FunctionAST.h
+++ b/include/cps/FunctionAST.h
@@ -35,6 +35,7 @@ class PrototypeAST {
     std::string OwnerClass;
     bool IsPublic;
     bool IsVariadic = false;
+    bool IsDefaultReturn = false;
     int Operator = 0;
 
 public:
@@ -49,6 +50,8 @@ public:
     const std::vector<ParamDecl> &getParams() const { return Params; }
     const std::string &getReturnType() const { return ReturnType; }
     bool isOverload() const { return IsOverload; }
+    bool isDefaultReturn() const { return IsDefaultReturn; }
+    void setDefaultReturn(bool V) { IsDefaultReturn = V; }
     int getOperator() const { return Operator; }
     void setOperator(int Op) { Operator = Op; }
     bool isExternal() const { return IsExternal; }
diff --git a/include/cps/FunctionGen.h b/include/cps/FunctionGen.h
index c3c530b..5e895fe 100644
--- a/include/cps/FunctionGen.h
+++ b/include/cps/FunctionGen.h
@@ -42,6 +42,7 @@ struct FuncSig {
     std::string ParamKey;
     std::string ReturnKey;
     bool IsOverload = false;
+    bool IsDefaultReturn = false;
     const PrototypeAST *Prototype = nullptr;
     std::string ReturnTypeName;
     std::vector<ParamSig> Params;
@@ -122,6 +123,7 @@ public:
     void setVisibility(std::function<bool(size_t)> Predicate) { Visible = std::move(Predicate); }
     std::vector<const FuncSig *> getOverloads(const std::string &Name, bool AllUnits = false) const;
     static bool isReservedRuntimeName(const std::string &Name);
+    static const FuncSig *selectDefaultReturn(const std::vector<const FuncSig *> &Candidates);
     bool hasFunction(const std::string &Name) const { return !getOverloads(Name).empty(); }
     const FuncSig *getSignatureByLink(const std::string &Name) const;
 
diff --git a/include/cps/Lexer.h b/include/cps/Lexer.h
index 3d057a3..1268582 100644
--- a/include/cps/Lexer.h
+++ b/include/cps/Lexer.h
@@ -79,6 +79,7 @@ enum Token {
     tok_call = -406,
     tok_byref = -407,
     tok_byval = -408,
+    tok_default = -409,
 
     tok_openfile = -500,
     tok_readfile = -501,