Copyright 1996-2000, Critical Mass, Inc. All rights reserved.
See file COPYRIGHT-CMASS for details.
UNSAFE MODULE String16;
IMPORT Word;
TYPE Ptr = UNTRACED REF WIDECHAR;
PROCEDURE Equal (a, b: ADDRESS; len: CARDINAL): BOOLEAN =
VAR pa := LOOPHOLE (a, Ptr); pb := LOOPHOLE (b, Ptr);
BEGIN
IF (len = 0) THEN RETURN TRUE; END;
IF (a = NIL) OR (b = NIL) THEN RETURN FALSE; END;
WHILE (len > 0) AND (pa^ = pb^) DO
DEC (len); INC (pa, ADRSIZE (pa^)); INC (pb, ADRSIZE (pb^));
END;
RETURN (len = 0);
END Equal;
PROCEDURE Compare (a: ADDRESS; len_a: CARDINAL;
b: ADDRESS; len_b: CARDINAL): [-1..1] =
CONST Map = ARRAY BOOLEAN OF [-1..+1] { +1, -1 };
VAR
pa := LOOPHOLE (a, Ptr);
pb := LOOPHOLE (b, Ptr);
len := MIN (len_a, len_b);
BEGIN
WHILE (len > 0) AND (pa^ = pb^) DO
DEC (len); INC (pa, ADRSIZE (pa^)); INC (pb, ADRSIZE (pb^));
END;
IF (len # 0) THEN RETURN Map [pa^ < pb^];
ELSIF (len_a # len_b) THEN RETURN Map [len_a < len_b];
ELSE RETURN 0;
END;
END Compare;
PROCEDURE Hash (a: ADDRESS; len: CARDINAL; initial: INTEGER): INTEGER =
VAR p := LOOPHOLE (a, Ptr); result := initial;
BEGIN
IF (p = NIL) THEN RETURN result; END;
WHILE (len > 0) DO
result := Word.Xor (Word.LeftRotate (result, 13), ORD (p^));
INC (p, ADRSIZE (p^)); DEC (len);
END;
RETURN result;
END Hash;
PROCEDURE FindChar (a: ADDRESS; len: CARDINAL; c: WIDECHAR): INTEGER =
VAR p := LOOPHOLE (a, Ptr); cnt := len;
BEGIN
IF (p = NIL) THEN RETURN -1; END;
WHILE (cnt > 0) DO
IF (p^ = c) THEN RETURN len - cnt; END;
INC (p, ADRSIZE (p^)); DEC (cnt);
END;
RETURN -1;
END FindChar;
PROCEDURE FindCharR (a: ADDRESS; len: CARDINAL; c: WIDECHAR): INTEGER =
VAR p := LOOPHOLE (a + len * ADRSIZE (WIDECHAR), Ptr);
BEGIN
IF (p = NIL) THEN RETURN -1; END;
WHILE (len > 0) DO
DEC (p, ADRSIZE (p^)); DEC (len);
IF (p^ = c) THEN RETURN len; END;
END;
RETURN -1;
END FindCharR;
PROCEDURE ArrayStart (READONLY a: ARRAY OF WIDECHAR): ADDRESS =
BEGIN
IF NUMBER (a) < 1 THEN RETURN NIL; END;
RETURN ADR (a[0]);
END ArrayStart;
BEGIN
END String16.