IMPLEMENTATION MODULE M2Strings;
(*
 *  REPERTOIRE
 *  Release 1.6
 *  By Charles Bradford and Cole Brecheen
 *  (c) Copyright 1985-1992 PMI
 *  Green Bay, Wisconsin
 *  All rights reserved
 *  (414) 468-6040
 *
 *  $Header:   D:/logfiles/mods/m2string.mov   1.5   10 Mar 1991 15:29:14   coleb  $
 *
 *)


IMPORT LowLevel;
IMPORT SYSTEM;
IMPORT PosUtils;

VAR
  Initialized : BOOLEAN;

  PROCEDURE Init();
    BEGIN
      IF Initialized THEN
        RETURN;
      ELSE
        Initialized := TRUE;
      END;
      LowLevel.Init();
      PosUtils.Init();
    END Init;


  PROCEDURE Assign(VAR source : ARRAY OF CHAR; VAR dest : ARRAY OF CHAR);
    VAR
      size1, size2 : CARDINAL;
    BEGIN
      size1 := HIGH(source)+1;
      size2 := HIGH(dest)+1;
      IF size1>=size2 THEN
        LowLevel.Move(SYSTEM.ADR(source), SYSTEM.ADR(dest), size2);
      ELSE
        LowLevel.Move(SYSTEM.ADR(source), SYSTEM.ADR(dest), size1);
        dest[size1] := 0C;
      END;
    END Assign;


  PROCEDURE Insert(substr : ARRAY OF CHAR; VAR str : ARRAY OF CHAR;
      inx : CARDINAL);
    VAR
      room, lngth1, size2 : CARDINAL;
    BEGIN
      lngth1 := Length(substr);
      IF (lngth1=0) OR (inx>HIGH(str)) THEN
        RETURN;
      END;
      size2 := HIGH(str)+1;
      room := size2-inx;
      LowLevel.ShiftArrayRight(SYSTEM.ADR(str[inx]), room, lngth1);
      IF lngth1>room THEN
        LowLevel.Move(SYSTEM.ADR(substr), SYSTEM.ADR(str[inx]), room);
      ELSE
        LowLevel.Move(SYSTEM.ADR(substr), SYSTEM.ADR(str[inx]), lngth1);
      END;
    END Insert;


  PROCEDURE Delete(VAR str : ARRAY OF CHAR; inx : CARDINAL; len :
      CARDINAL);
    VAR
      room, lngth : CARDINAL;
    BEGIN
      lngth := Length(str);
      IF (len=0) OR (inx>=lngth) THEN
        RETURN;
      END;
      room := lngth-inx;
      IF len>room THEN
        len := room;
      END;
      IF room>1 THEN
        LowLevel.ShiftArrayLeft(SYSTEM.ADR(str[inx]), room, len);
      END;
      str[lngth-len] := 0C;
    END Delete;


  PROCEDURE Pos(substr, str : ARRAY OF CHAR) : CARDINAL;
    BEGIN
      RETURN PosUtils.Pos(substr,str);
    END Pos;


  PROCEDURE Copy(str : ARRAY OF CHAR; inx : CARDINAL; len : CARDINAL;
    VAR result : ARRAY OF CHAR);
    VAR
      lngth1, size2, room : CARDINAL;
    BEGIN
      lngth1 := Length(str);
      size2 := HIGH(result)+1;
      result[0] := 0C;
        (*This sets result to null in case we return from the
          procedure in the next statement.*)
      IF (len=0) OR (inx>=lngth1) THEN
        RETURN;
      END;
      room := lngth1-inx;
      IF len>room THEN
        len := room;
      END;
      IF len>=size2 THEN
        LowLevel.Move(SYSTEM.ADR(str[inx]), SYSTEM.ADR(result), size2);
      ELSE
        LowLevel.Move(SYSTEM.ADR(str[inx]), SYSTEM.ADR(result), len);
        result[len] := 0C;
      END;
    END Copy;


  PROCEDURE Concat(s1, s2 : ARRAY OF CHAR; VAR result : ARRAY OF CHAR);
    BEGIN
      Assign(s2, result);
      Insert(s1, result, 0);
    END Concat;


  PROCEDURE Length(VAR str : ARRAY OF CHAR) : CARDINAL;
    VAR
      StrSize, skipped : INTEGER;
    BEGIN
      StrSize := INTEGER(HIGH(str)+1);
      skipped := LowLevel.ScanEQ(StrSize,0C,SYSTEM.ADR(str));
      RETURN CARDINAL(skipped);
    END Length;


  PROCEDURE CompareStr(s1, s2 : ARRAY OF CHAR) : INTEGER;
    VAR
      TmpAdr1, TmpAdr2 : LowLevel.Address8086;
      len1, len2, CompLen, cnt : CARDINAL;
      result: INTEGER;
    BEGIN
      result := 0;
      TmpAdr1.a := SYSTEM.ADR(s1);
      TmpAdr2.a := SYSTEM.ADR(s2);
      len1 := Length(s1);
      len2 := Length(s2);
      IF (HIGH(s1)+1) < len1 THEN len1 := HIGH(s1)+1 END;
      IF (HIGH(s2)+1) < len2 THEN len2 := HIGH(s2)+1 END;
      CompLen := len1;
      IF CompLen > len2 THEN
        CompLen := len2;
      END;
      cnt := 0;
      WHILE (cnt < CompLen) AND (result = 0) DO
        IF TmpAdr1.b^ # TmpAdr2.b^ THEN
          IF TmpAdr1.b^ > TmpAdr2.b^ THEN
            result := 1;
            RETURN result;
          ELSE
            result := -1;
            RETURN result;
          END;
        ELSE
          INC(cnt);
          INC(TmpAdr1.off);
          INC(TmpAdr2.off);
        END;
      END;
      IF len1 = len2 THEN
        result := 0;
      ELSIF len1 > len2 THEN
        result := 1;
      ELSE
        result := -1;
      END;
      RETURN result;
    END CompareStr;


BEGIN
  Initialized := FALSE;
  Init();
END M2Strings.