MODULE Builtins; (** AUTHOR "fof"; PURPOSE "Built-in functions for the Active Oberon Compiler"; *)
IMPORT SYSTEM;

VAR
	kernelModule-: ARRAY 32 OF ADDRESS;
	modules-: LONGINT;

PROCEDURE InsertModule*(a: ADDRESS): BOOLEAN;
BEGIN
	kernelModule[modules] := a;
	INC(modules);
	RETURN TRUE
END InsertModule;

(* compare strings,
	returns 0 if strings are equal,
	returns +1 if left is lexicographic greater than right,
	returns -1 if left is lexicographics smaller than right
	traps if src or destination is not 0X terminated and comparison is not finished
*)
PROCEDURE CompareString*(CONST left,right: ARRAY OF CHAR): SHORTINT;
VAR i: LONGINT; res: SHORTINT; l,r: CHAR;
BEGIN
	i := 0; res := 0;
	LOOP
		l := left[i]; 		(* index check included *)
		r := right[i];		(* index check included *)
		IF (res = 0) THEN
			IF (l > r) THEN
				res := 1; EXIT
			ELSIF (l<r) THEN
				res := -1; EXIT
			ELSIF l=0X THEN
				EXIT
			END;
		END;
		INC(i);
	END;
	RETURN res
END CompareString;

(* copy string from src to dest, emits trap if not 0X terminated or destination too short *)
PROCEDURE CopyString*(VAR dest: ARRAY OF CHAR; CONST src: ARRAY OF CHAR);
VAR i: LONGINT; ch :CHAR; l1,l2: LONGINT;
BEGIN
	(*
	i := 0;
	REPEAT
		ch := src[i];		(* index check included *)
		dest[i] := ch;	(* index check included *)
		INC(i);
	UNTIL ch=0X;
	*)

	(*! currently implemented: old PACO semantics *)
	l1 := LEN(dest);
	l2 := LEN(src);
	IF l2 < l1 THEN l1 := l2 END;
	SYSTEM.MOVE(ADDRESSOF(src[0]),ADDRESSOF(dest[0]),l1);
	dest[l1-1] := 0X;
END CopyString;

BEGIN
	(*! assumed that modules = 0, implicit call of InsertModule *)
END Builtins.