MODULE PL0;

FROM	InOut	IMPORT	Read, ReadString,
						Write, WriteString, WriteLn,
						OpenInput, CloseInput,
						Done;

FROM	SyntaxAnalysis	IMPORT	parse, SyntaxError;
FROM	Synthesis		IMPORT	traverse, SemanticError;
FROM	Generator		IMPORT	CodeStore;
FROM	Interpreter		IMPORT	Interpret;
FROM	InternalTree	IMPORT	blckPtr;

IMPORT STextIO,FIO;
FROM Strings IMPORT Length;

VAR 
	InputFileName 	: ARRAY[0..40] OF CHAR;
    TREE 			: blckPtr;
    c 				: CHAR;
	DEBUG 			: BOOLEAN;
	jamais			: CARDINAL;

	PROCEDURE ReadLn(VAR c: CHAR);
		VAR lc : CHAR;
	BEGIN
		REPEAT
			Read(c)
		UNTIL c > ' ';
		REPEAT
			Read(lc)
		UNTIL (lc = 12C) OR (lc = 15C)
	END ReadLn;

	PROCEDURE ApendExtension;
		VAR i : CARDINAL;
	BEGIN
		i := 0;
		LOOP
			IF InputFileName[i] = 0C THEN
			InputFileName[i] := '.'; 
			INC(i);
			InputFileName[i] := 'p'; 
			INC(i);
			InputFileName[i] := 'l'; 
			INC(i);
			InputFileName[i] := '0'; 
			INC(i);
			InputFileName[i] := 0C;
			EXIT
			END;
			IF (InputFileName[i] = '.') OR (i = 40) THEN EXIT END;
			INC(i)
		END
	END ApendExtension;

BEGIN
	DEBUG := TRUE;
	STextIO.WriteString("PL0 Compiler/Interpreter"); 
	WriteLn;
	STextIO.WriteString("First implementation by : "); 
	WriteLn;
	STextIO.WriteString("First Working Version : Eric Streit <eric@yojik.eu> 18/05/2026"); 
	WriteLn;
	LOOP
		InputFileName := "";
		Done := FALSE;
		STextIO.WriteLn;
		STextIO.WriteString("Entrez le nom de fichier PL0 > ");
		OpenInput("pl0");
		IF DEBUG THEN
			STextIO.WriteString("***");
			IF Done THEN 
				WriteString("TRUE");
			END;
			STextIO.WriteString("***");
			STextIO.WriteLn;
		END;
		IF Done THEN
			STextIO.WriteLn;
			STextIO.WriteString("Syntactic Analyser"); 
			STextIO.WriteLn;
			TREE := parse();
			CloseInput;		(* read again from standard input *)
			IF NOT SyntaxError THEN
				STextIO.WriteLn;
				STextIO.WriteString("Semantic Analysis und Code Generation"); 
				STextIO.WriteLn;
				traverse(TREE);
				IF NOT SemanticError THEN
					REPEAT
						STextIO.WriteLn;
						STextIO.WriteString("Programm translation and run (y/n) ?");
						STextIO.ReadChar(c);
						IF c = "y" THEN
							STextIO.WriteLn;
							Interpret(CodeStore)
						ELSE
							HALT
						END
					UNTIL c = 'n'
				END
			END
		ELSE
			Write("'");
			WriteString(InputFileName); WriteString("' not found");
			WriteLn
		END;
	END; (* loop *)
	
END PL0.