From e3ed34c205ee2581f496439af92ca2918f681bb2 Mon Sep 17 00:00:00 2001
From: Pasha Bibko <156938226+PashaBibko@users.noreply.github.com>
Date: Mon, 4 Aug 2025 16:07:35 +0100
Subject: [PATCH] Added ParseFunctionCall

---
 ast/inc/NodeTypes.h   |  2 +-
 ast/src/NodeTypes.cpp |  4 ++--
 parser/src/Parser.cpp | 43 ++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/ast/inc/NodeTypes.h b/ast/inc/NodeTypes.h
index af24b92..5a8bd31 100644
--- a/ast/inc/NodeTypes.h
+++ b/ast/inc/NodeTypes.h
@@ -10,7 +10,7 @@ namespace LXC::AST
     class FunctionCall final : public NodeValue
     {
         public:
-            FunctionCall(Identifier& functionName, ValueList& arguments);
+            FunctionCall(const Identifier& functionName, ValueList& arguments);
     
         private:
             // The name of the function //
diff --git a/ast/src/NodeTypes.cpp b/ast/src/NodeTypes.cpp
index 952bf55..d847a3e 100644
--- a/ast/src/NodeTypes.cpp
+++ b/ast/src/NodeTypes.cpp
@@ -4,8 +4,8 @@
 
 namespace LXC::AST
 {
-    FunctionCall::FunctionCall (Identifier& functionName, ValueList& arguments)
-        : NodeValue(NodeType::FunctionCall), m_FuncName(std::move(functionName)), m_Arguments(std::move(arguments))
+    FunctionCall::FunctionCall (const Identifier& functionName, ValueList& arguments)
+        : NodeValue(NodeType::FunctionCall), m_FuncName(functionName), m_Arguments(std::move(arguments))
     {}
 
     IntLiteral::IntLiteral(const std::string_view& value)
diff --git a/parser/src/Parser.cpp b/parser/src/Parser.cpp
index eee7b0b..e8b96bd 100644
--- a/parser/src/Parser.cpp
+++ b/parser/src/Parser.cpp
@@ -10,6 +10,13 @@ namespace LXC::Internal
     {
         return Util::ReturnVal<AST::NodePtr, Parser::ParserError>(std::make_unique<NodeType>(std::forward<Args>(args)...));
     }
+
+    template<typename NodeType, typename... Args>
+        requires std::is_base_of_v<AST::NodeValue, NodeType> && std::is_constructible_v<NodeType, Args...>
+    static const inline Util::ReturnVal<AST::NodeValuePtr, Parser::ParserError> CreateNodeV(Args&&... args)
+    {
+        return Util::ReturnVal<AST::NodeValuePtr, Parser::ParserError>(std::make_unique<NodeType>(std::forward<Args>(args)...));
+    }
 }
 
 namespace LXC::Parser
@@ -73,7 +80,7 @@ namespace LXC::Parser
             const size_t length;
     };
 
-    static Util::ReturnVal<AST::NodePtr, ParserError> ParsePrimary(ParserContext& ctx)
+    static Util::ReturnVal<AST::NodeValuePtr, ParserError> ParsePrimary(ParserContext& ctx)
     {
         // Gets the current token and returns if out of bounds //
         const Lexer::Token* current = ctx.At();
@@ -85,10 +92,12 @@ namespace LXC::Parser
         {
             // Fowards to the ParseIdentifier and returns the result/error //
             case Lexer::Token::Identifier:
+                ctx.Advance();
                 return Internal::CreateNode<AST::VarAccess>(current->Str());
 
             // Returns an integer literal node //
             case Lexer::Token::NumLiteral:
+                ctx.Advance();
                 return Internal::CreateNode<AST::IntLiteral>(current->Str());
 
             default:
@@ -97,6 +106,38 @@ namespace LXC::Parser
         }
     }
 
+    static Util::ReturnVal<AST::NodeValuePtr, ParserError> ParseFunctionCall(ParserContext& ctx)
+    {
+        // Checks if the upcoming pattern matches a function signature: [Identifier(function name), OpenBracket(Start of params)] //
+        if (!ctx.Expect(std::array{ Lexer::Token::Identifier, Lexer::Token::OpenParen }))
+        {
+            // Captures the function name and advances over it and the start paren //
+            const Lexer::Token* functionNameToken = ctx.At();
+            ctx.Advance(2);
+
+            // Captures the arguments of the function call //
+            AST::ValueList arguments;
+            const Lexer::Token* current = ctx.At();
+            while (current != nullptr)
+            {
+                // End of the function call //
+                if (current->type == Lexer::Token::CloseParen)
+                    return Internal::CreateNodeV<AST::FunctionCall>(functionNameToken->Str(), arguments);
+
+                // Checks for seperating comma //
+                if (!ctx.Expect(std::array{ Lexer::Token::Comma }))
+                    return Util::FunctionFail<ParserError>(); // <- TODO: Make an actual error
+                ctx.Advance();
+
+                // Adds the current argument to the ValueList //
+                arguments.push_back(ParsePrimary(ctx));
+            }
+        }
+
+        // Else fowards to the next function in the call stack //
+        return ParsePrimary(ctx);
+    }
+
     static Util::ReturnVal<AST::NodePtr, ParserError> ParseOperation(ParserContext& ctx)
     {}