1 files changed, 139 insertions, 0 deletions
diff --git a/lib/Parser/ParserFunction.cc b/lib/Parser/ParserFunction.cc
new file mode 100644
index 0000000..d689aa6
--- /dev/null
+++ b/lib/Parser/ParserFunction.cc
@@ -0,0 +1,139 @@
+#include "cps/Parser.h"
+#include "cps/FunctionAST.h"
+#include <tuple>
+
+using namespace cps;
+
+std::vector<std::tuple<std::string, std::string, bool>> Parser::ParsePrototypeArgs() {
+    std::vector<std::tuple<std::string, std::string, bool>> Args;
+    if (CurTok != '(') return Args;
+    getNextToken();
+
+    while (CurTok != ')') {
+        if (CurTok == -1000 || CurTok == -1001) getNextToken();
+
+        bool IsRef = false;
+        if (CurTok == tok_byref) {
+            IsRef = true;
+            getNextToken();
+        } else if (CurTok == tok_byval) {
+            IsRef = false;
+            getNextToken();
+        }
+
+        if (CurTok != tok_identifier) {
+            fprintf(stderr, "Error: Expected argument name\n");
+            return Args;
+        }
+        std::string Name = Lex.IdentifierStr;
+        getNextToken();
+
+        if (CurTok != tok_colon) {
+            fprintf(stderr, "Error: Expected ':' after argument name\n");
+            return Args;
+        }
+        getNextToken();
+
+        std::string Type = "INTEGER";
+        if (CurTok == tok_integer_kw) {
+            getNextToken();
+        } else if (CurTok == tok_identifier) {
+            Type = Lex.IdentifierStr; 
+            getNextToken();
+        } else {
+             fprintf(stderr, "Error: Expected type (e.g. INTEGER) for argument '%s'\n", Name.c_str());
+             return Args;
+        }
+
+        Args.emplace_back(Name, Type, IsRef);
+
+        if (CurTok == ')') break;
+        if (CurTok != ',') {
+            fprintf(stderr, "Error: Expected ',' or ')'\n");
+            return Args;
+        }
+        getNextToken();
+    }
+    getNextToken();
+    return Args;
+}
+
+
+std::unique_ptr<StmtAST> Parser::ParseFunction() {
+    getNextToken();
+    std::string Name = Lex.IdentifierStr;
+    getNextToken();
+
+    auto Args = ParsePrototypeArgs();
+
+    std::string RetType = "INTEGER";
+    if (CurTok == tok_returns) { 
+        getNextToken();
+        getNextToken();
+    }
+
+    auto Proto = std::make_unique<PrototypeAST>(Name, std::move(Args), RetType);
+
+    std::vector<std::unique_ptr<StmtAST>> Body;
+    while (CurTok != tok_endfunction && CurTok != tok_eof) {
+        auto Stmt = ParseStatement();
+        if (Stmt) Body.push_back(std::move(Stmt));
+        else if (CurTok != tok_eof && CurTok != tok_endfunction) getNextToken();
+    }
+    getNextToken();
+
+    return std::make_unique<FunctionDefAST>(std::move(Proto), std::move(Body));
+}
+
+std::unique_ptr<StmtAST> Parser::ParseProcedure() {
+    getNextToken();
+    std::string Name = Lex.IdentifierStr;
+    getNextToken();
+
+    auto Args = ParsePrototypeArgs();
+    auto Proto = std::make_unique<PrototypeAST>(Name, std::move(Args), "VOID");
+
+    std::vector<std::unique_ptr<StmtAST>> Body;
+    while (CurTok != tok_endprocedure && CurTok != tok_eof) {
+        auto Stmt = ParseStatement();
+        if (Stmt) Body.push_back(std::move(Stmt));
+        else if (CurTok != tok_eof && CurTok != tok_endprocedure) getNextToken();
+    }
+    getNextToken();
+
+    return std::make_unique<FunctionDefAST>(std::move(Proto), std::move(Body));
+}
+
+std::unique_ptr<StmtAST> Parser::ParseCallStmt() {
+    getNextToken();
+    std::string Callee = Lex.IdentifierStr;
+    getNextToken();
+
+    std::vector<std::unique_ptr<ExprAST>> Args;
+    if (CurTok == '(') {
+        getNextToken();
+        while (CurTok != ')') {
+            auto Arg = ParseExpression();
+            if (Arg) Args.push_back(std::move(Arg));
+            
+            if (CurTok == ')') break;
+            if (CurTok != ',') {
+                fprintf(stderr, "Error: Expected ',' or ')' in call\n");
+                return nullptr;
+            }
+            getNextToken();
+        }
+        getNextToken();
+    }
+    
+    return std::make_unique<CallStmtAST>(Callee, std::move(Args));
+}
+
+std::unique_ptr<StmtAST> Parser::ParseReturnStmt() {
+    getNextToken();
+    std::unique_ptr<ExprAST> Expr = nullptr;
+    if (CurTok != tok_endif && CurTok != tok_else && CurTok != tok_endfunction && CurTok != tok_endprocedure) {
+        Expr = ParseExpression();
+    }
+    return std::make_unique<ReturnStmtAST>(std::move(Expr));
+}