refactor(parser): split expression and control flow parsing

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

1 files changed, 0 insertions, 484 deletions

diff --git a/lib/Parser/Parser.cc b/lib/Parser/Parser.cc
index db2790b..3e8a096 100644
--- a/lib/Parser/Parser.cc
+++ b/lib/Parser/Parser.cc
@@ -28,258 +28,10 @@ Parser::Parser(Lexer &L) : Lex(L) {
     BinopPrecedence[tok_mod] = 40;
 }
 
-int Parser::GetTokPrecedence() {
-    if (BinopPrecedence.find(CurTok) == BinopPrecedence.end()) return -1;
-    int TokPrec = BinopPrecedence[CurTok];
-    if (TokPrec <= 0) return -1;
-    return TokPrec;
-}
-
 int Parser::getNextToken() {
     return CurTok = Lex.gettok();
 }
 
-std::unique_ptr<ExprAST> Parser::ParseNumberExpr() {
-    if (CurTok == tok_number_real) {
-        auto Result = std::make_unique<RealExprAST>(Lex.RealVal);
-        getNextToken();
-        return Result;
-    }
-    auto Result = std::make_unique<IntegerExprAST>(Lex.NumVal);
-    getNextToken();
-    return Result;
-}
-
-std::unique_ptr<ExprAST> Parser::ParseIdentifierExpr() {
-    std::string IdName = Lex.IdentifierStr;
-    int Line = Lex.getLine();
-    getNextToken();
-
-    if (CurTok == '(') {
-        getNextToken();
-        auto Args = ParseExprList(')', true);
-        if (!Args) return nullptr;
-        if (CurTok == '[' || CurTok == '.' || CurTok == '^') {
-            fprintf(stderr, "error: record/array/pointer access on a function result is not supported at line %d\n",
-                    Lex.getLine());
-            return nullptr;
-        }
-        return std::make_unique<CallExprAST>(IdName, std::move(*Args), Line);
-    }
-
-    std::vector<DesignatorAccess> Accesses;
-    if (!ParseDesignatorSuffix(Accesses)) return nullptr;
-
-    // Degrade rule: shapes that existed before designators keep their nodes.
-    if (Accesses.empty())
-        return std::make_unique<VariableExprAST>(IdName);
-    if (Accesses.size() == 1 && Accesses[0].Kind == AccessKind::Index)
-        return std::make_unique<ArrayAccessExprAST>(IdName, std::move(Accesses[0].Indices), Line);
-    return std::make_unique<DesignatorExprAST>(IdName, std::move(Accesses), Line);
-}
-
-// Postfix accessor chain after an identifier: '[' exprs ']' | '.' IDENT | '^'
-bool Parser::ParseDesignatorSuffix(std::vector<DesignatorAccess> &Out) {
-    while (true) {
-        if (CurTok == '[') {
-            getNextToken();
-            auto Indices = ParseExprList(']', false);
-            if (!Indices) return false;
-            DesignatorAccess A;
-            A.Kind = AccessKind::Index;
-            A.Indices = std::move(*Indices);
-            Out.push_back(std::move(A));
-        } else if (CurTok == '.') {
-            getNextToken();
-            if (CurTok != tok_identifier) {
-                fprintf(stderr, "error: Expected field name after '.' at line %d\n", Lex.getLine());
-                return false;
-            }
-            DesignatorAccess A;
-            A.Kind = AccessKind::Field;
-            A.FieldName = Lex.IdentifierStr;
-            Out.push_back(std::move(A));
-            getNextToken();
-        } else if (CurTok == '^') {
-            getNextToken();
-            DesignatorAccess A;
-            A.Kind = AccessKind::Deref;
-            Out.push_back(std::move(A));
-        } else {
-            return true;
-        }
-    }
-}
-
-std::string Parser::ParseTypeName(bool AllowVoid) {
-    switch (CurTok) {
-    case tok_c_int: getNextToken(); return "C_INT";
-    case tok_c_char: getNextToken(); return "C_CHAR";
-    case tok_c_string: getNextToken(); return "C_STRING";
-    case tok_c_double: getNextToken(); return "C_DOUBLE";
-    default: break;
-    }
-    if (CurTok == tok_integer_kw) {
-        getNextToken();
-        return "INTEGER";
-    }
-    if (CurTok == tok_real_kw) {
-        getNextToken();
-        return "REAL";
-    }
-    if (CurTok == tok_boolean_kw) {
-        getNextToken();
-        return "BOOLEAN";
-    }
-    if (CurTok == tok_string_kw) {
-        getNextToken();
-        return "STRING";
-    }
-    if (CurTok == tok_char_kw) {
-        getNextToken();
-        return "CHAR";
-    }
-    if (CurTok == tok_identifier) {
-        std::string TypeName = Lex.IdentifierStr;
-        if (!AllowVoid && TypeName == "VOID") {
-            fprintf(stderr, "error: VOID is not allowed here\n");
-            return "";
-        }
-        getNextToken();
-        return TypeName;
-    }
-
-    fprintf(stderr, "error: Unknown type name\n");
-    return "";
-}
-
-std::unique_ptr<ExprAST> Parser::ParseParenExpr() {
-    getNextToken();
-    bool IsType = CurTok == tok_integer_kw || CurTok == tok_real_kw ||
-        CurTok == tok_boolean_kw || CurTok == tok_string_kw || CurTok == tok_char_kw ||
-        CurTok == tok_c_int || CurTok == tok_c_char || CurTok == tok_c_string ||
-        CurTok == tok_c_double ||
-        (CurTok == tok_identifier && TypeNames.count(Lex.IdentifierStr));
-    if (IsType) {
-        std::string TypeName = ParseTypeName();
-        if (TypeName.empty()) return nullptr;
-        if (CurTok != ')') {
-            fprintf(stderr, "error: Expected ')' after cast type at line %d\n", Lex.getLine());
-            return nullptr;
-        }
-        getNextToken();
-        auto Operand = ParseUnary();
-        if (!Operand) return nullptr;
-        return std::make_unique<CastExprAST>(TypeName, std::move(Operand));
-    }
-    auto V = ParseExpression();
-    if (!V) return nullptr;
-    if (CurTok != ')') {
-        fprintf(stderr, "error: expected ')'\n");
-        return nullptr;
-    }
-    getNextToken();
-    return V;
-}
-
-std::unique_ptr<ExprAST> Parser::ParsePrimary() {
-    switch (CurTok) {
-    case tok_identifier: return ParseIdentifierExpr();
-    case tok_number_int: return ParseNumberExpr();
-    case tok_number_real: return ParseNumberExpr();
-    case tok_string_literal: {
-        auto Res = std::make_unique<StringExprAST>(Lex.StringVal);
-        getNextToken();
-        return Res;
-    }
-    case tok_char_literal: {
-        auto Res = std::make_unique<CharExprAST>(Lex.CharVal);
-        getNextToken();
-        return Res;
-    }
-    case tok_true: {
-        getNextToken();
-        return std::make_unique<BooleanExprAST>(true);
-    }
-    case tok_false: {
-        getNextToken();
-        return std::make_unique<BooleanExprAST>(false);
-    }
-    case '(':            return ParseParenExpr();
-    default:
-        fprintf(stderr, "error: unknown token '%c' (%d) at line %d when expecting an expression\n",
-                (char)CurTok, CurTok, Lex.getLine());
-        return nullptr;
-    }
-}
-
-std::unique_ptr<ExprAST> Parser::ParseUnary() {
-    if (CurTok == tok_not) {
-        getNextToken();
-        auto Operand = ParseUnary();
-        if (!Operand) return nullptr;
-        return std::make_unique<UnaryExprAST>(tok_not, std::move(Operand));
-    }
-
-    // ^<designator> — address-of; the operand must be an lvalue shape.
-    if (CurTok == '^') {
-        int Line = Lex.getLine();
-        getNextToken();
-        if (CurTok != tok_identifier) {
-            fprintf(stderr, "error: '^' (address-of) requires a variable, array element or record field at line %d\n",
-                    Line);
-            return nullptr;
-        }
-        std::string BaseName = Lex.IdentifierStr;
-        getNextToken();
-        if (CurTok == '(') {
-            fprintf(stderr, "error: cannot take the address of a function result at line %d\n", Line);
-            return nullptr;
-        }
-        std::vector<DesignatorAccess> Accesses;
-        if (!ParseDesignatorSuffix(Accesses)) return nullptr;
-        auto Target = std::make_unique<DesignatorExprAST>(BaseName, std::move(Accesses), Line);
-        return std::make_unique<AddrOfExprAST>(std::move(Target));
-    }
-
-    if (CurTok == '-') {
-        getNextToken();
-        auto Operand = ParseUnary();
-        if (!Operand) return nullptr;
-        return std::make_unique<UnaryExprAST>('-', std::move(Operand));
-    }
-
-    return ParsePrimary();
-}
-
-std::unique_ptr<ExprAST> Parser::ParseBinOpRHS(int ExprPrec, std::unique_ptr<ExprAST> LHS) {
-    while (true) {
-        int TokPrec = GetTokPrecedence();
-        if (TokPrec < ExprPrec) return LHS;
-
-        int BinOp = CurTok;
-        int Line = Lex.getLine();
-        getNextToken();
-
-        auto RHS = ParseUnary();
-        if (!RHS) return nullptr;
-
-        int NextPrec = GetTokPrecedence();
-        if (TokPrec < NextPrec) {
-            RHS = ParseBinOpRHS(TokPrec + 1, std::move(RHS));
-            if (!RHS) return nullptr;
-        }
-
-        LHS = std::make_unique<BinaryExprAST>(BinOp, std::move(LHS), std::move(RHS), Line);
-    }
-}
-
-std::unique_ptr<ExprAST> Parser::ParseExpression() {
-    auto LHS = ParseUnary();
-    if (!LHS) return nullptr;
-    return ParseBinOpRHS(0, std::move(LHS));
-}
-
 std::vector<std::unique_ptr<StmtAST>> Parser::Parse() {
     return ParseBlock({});
 }
@@ -327,242 +79,6 @@ std::vector<std::unique_ptr<StmtAST>> Parser::ParseBlock(std::initializer_list<i
     return Body;
 }
 
-std::optional<std::vector<std::unique_ptr<ExprAST>>> Parser::ParseExprList(char CloseDelim, bool AllowEmpty) {
-    std::vector<std::unique_ptr<ExprAST>> Elems;
-    if (AllowEmpty && CurTok == CloseDelim) {
-        getNextToken();
-        return Elems;
-    }
-
-    while (true) {
-        auto E = ParseExpression();
-        if (!E) return std::nullopt;
-        Elems.push_back(std::move(E));
-
-        if (CurTok == CloseDelim) break;
-        if (CurTok != ',') {
-            fprintf(stderr, "error: Expected ',' or '%c' at line %d\n", CloseDelim, Lex.getLine());
-            return std::nullopt;
-        }
-        getNextToken();
-    }
-    getNextToken();
-    return Elems;
-}
-
-std::unique_ptr<StmtAST> Parser::ParseDeclare() {
-    getNextToken();
-    if (CurTok != tok_identifier) {
-        fprintf(stderr, "error: Expected identifier after DECLARE at line %d\n", Lex.getLine());
-        return nullptr;
-    }
-    std::string Name = Lex.IdentifierStr;
-    getNextToken();
-
-    if (CurTok != tok_colon) {
-        fprintf(stderr, "error: Expected ':' after variable name '%s' at line %d\n", Name.c_str(), Lex.getLine());
-        return nullptr;
-    }
-    getNextToken();
-    
-    if (CurTok == tok_array) {
-        getNextToken(); 
-        if (CurTok != '[') {
-            fprintf(stderr, "error: Expected '[' after ARRAY\n");
-            return nullptr;
-        }
-        getNextToken();
-        
-        std::vector<std::pair<std::unique_ptr<ExprAST>, std::unique_ptr<ExprAST>>> Bounds;
-        
-        while (true) {
-            auto Lower = ParseExpression();
-            if (!Lower) return nullptr;
-            
-            if (CurTok != tok_colon) {
-                fprintf(stderr, "error: Expected ':' in array range (e.g. 1:10)\n");
-                return nullptr;
-            }
-            getNextToken();
-            
-            auto Upper = ParseExpression();
-            if (!Upper) return nullptr;
-            
-            Bounds.push_back({std::move(Lower), std::move(Upper)});
-            
-            if (CurTok == ']') break;
-            if (CurTok == ',') {
-                getNextToken();
-                continue;
-            }
-            fprintf(stderr, "error: Expected ',' or ']' in array dims\n");
-            return nullptr;
-        }
-        getNextToken();
-        
-        if (CurTok != tok_of) {
-            fprintf(stderr, "error: Expected OF after array dims\n");
-            return nullptr;
-        }
-        getNextToken();
-
-        std::string TypeStr = ParseTypeName(false);
-        if (TypeStr.empty()) {
-            return nullptr;
-        }
-        
-        return std::make_unique<ArrayDeclareStmtAST>(Name, std::move(Bounds), TypeStr);
-    } 
-    else {
-        std::string TypeStr = ParseTypeName(false);
-        if (TypeStr.empty()) {
-            return nullptr;
-        }
-        return std::make_unique<DeclareStmtAST>(Name, TypeStr);
-    }
-}
-
-std::unique_ptr<StmtAST> Parser::ParseTryStmt() {
-    getNextToken();
-    auto Body = ParseBlock({tok_catch, tok_endtry});
-    if (CurTok != tok_catch) {
-        fprintf(stderr, "error: Expected CATCH in TRY at line %d\n", Lex.getLine());
-        return nullptr;
-    }
-    getNextToken();
-    auto CatchBody = ParseBlock({tok_endtry, tok_catch});
-    if (CurTok != tok_endtry) {
-        fprintf(stderr, "error: Expected ENDTRY after CATCH at line %d\n", Lex.getLine());
-        return nullptr;
-    }
-    getNextToken();
-    return std::make_unique<TryStmtAST>(std::move(Body), std::move(CatchBody));
-}
-
-std::unique_ptr<StmtAST> Parser::ParseIfStmt() {
-    getNextToken();
-    auto Cond = ParseExpression();
-    if (!Cond) return nullptr;
-
-    if (CurTok != tok_then) {
-        fprintf(stderr, "error: expected THEN\n");
-        return nullptr;
-    }
-    getNextToken();
-
-    std::vector<std::unique_ptr<StmtAST>> ThenStmts = ParseBlock({tok_else, tok_endif});
-
-    std::vector<std::unique_ptr<StmtAST>> ElseStmts;
-    if (CurTok == tok_else) {
-        getNextToken();
-        ElseStmts = ParseBlock({tok_endif});
-    }
-
-    if (CurTok != tok_endif) {
-        fprintf(stderr, "error: expected ENDIF\n");
-        return nullptr;
-    }
-    getNextToken();
-
-    return std::make_unique<IfStmtAST>(std::move(Cond), std::move(ThenStmts), std::move(ElseStmts));
-}
-
-std::unique_ptr<StmtAST> Parser::ParseWhileStmt() {
-    getNextToken();
-    auto Cond = ParseExpression();
-    if (!Cond) return nullptr;
-
-    if (CurTok != tok_do) {
-        fprintf(stderr, "error: expected DO after WHILE condition\n");
-        return nullptr;
-    }
-    getNextToken();
-
-    std::vector<std::unique_ptr<StmtAST>> Body = ParseBlock({tok_endwhile});
-
-    if (CurTok != tok_endwhile) {
-        fprintf(stderr, "error: expected ENDWHILE\n");
-        return nullptr;
-    }
-    getNextToken();
-
-    return std::make_unique<WhileStmtAST>(std::move(Cond), std::move(Body));
-}
-
-std::unique_ptr<StmtAST> Parser::ParseRepeatStmt() {
-    getNextToken();
-
-    std::vector<std::unique_ptr<StmtAST>> Body = ParseBlock({tok_until});
-
-    if (CurTok != tok_until) {
-        fprintf(stderr, "error: expected UNTIL\n");
-        return nullptr;
-    }
-    getNextToken();
-
-    auto Cond = ParseExpression();
-    if (!Cond) return nullptr;
-
-    return std::make_unique<RepeatStmtAST>(std::move(Body), std::move(Cond));
-}
-
-std::unique_ptr<StmtAST> Parser::ParseForStmt() {
-    getNextToken();
-    if (CurTok != tok_identifier) {
-        fprintf(stderr, "error: expected identifier after FOR\n");
-        return nullptr;
-    }
-    std::string VarName = Lex.IdentifierStr;
-    getNextToken();
-
-    if (CurTok != tok_assign) {
-        fprintf(stderr, "error: expected '<-' in FOR loop\n");
-        return nullptr;
-    }
-    getNextToken();
-
-    auto Start = ParseExpression();
-    if (!Start) return nullptr;
-
-    if (CurTok != tok_to) {
-        fprintf(stderr, "error: expected TO in FOR loop\n");
-        return nullptr;
-    }
-    getNextToken();
-
-    auto End = ParseExpression();
-    if (!End) return nullptr;
-
-    std::unique_ptr<ExprAST> Step = nullptr;
-    if (CurTok == tok_step) {
-        getNextToken();
-        Step = ParseExpression();
-        if (!Step) return nullptr;
-    }
-
-    std::vector<std::unique_ptr<StmtAST>> Body = ParseBlock({tok_next});
-
-    if (CurTok != tok_next) {
-        fprintf(stderr, "error: expected NEXT\n");
-        return nullptr;
-    }
-    getNextToken();
-    
-    if (CurTok != tok_identifier) {
-        fprintf(stderr, "error: expected identifier after NEXT (e.g., NEXT %s)\n", VarName.c_str());
-        return nullptr;
-    }
-
-    if (Lex.IdentifierStr != VarName) {
-        fprintf(stderr, "error: NEXT identifier '%s' does not match FOR variable '%s'\n",
-                Lex.IdentifierStr.c_str(), VarName.c_str());
-        return nullptr;
-    }
-    getNextToken();
-
-    return std::make_unique<ForStmtAST>(VarName, std::move(Start), std::move(End), std::move(Step), std::move(Body));
-}
-
 std::unique_ptr<StmtAST> Parser::ParseStatement() {
     auto Stmt = ParseStatementImpl();
     if (!Stmt) ++NumErrors;