\ SEARCH.SEQ    String search routine.                  by Roger Bird

comment:

  This file may be removed, but it is used by WORDS.SEQ, and ENVIRON.SEQ,
which is itself used by EXEC.SEQ.

  The String manipulation primitives include string comparison and
searching. The string search implemented is used in the editor
to find the desired string.  The only unusual thing about it is
the presence of a variable called CAPS, which determines
whether or not to ignore the case of the subject and pattern
strings.  If case is ignored then A-Z = a-z.  The default is
ignore case.

        Much thanks to Roger Bird for this improved impilmentation
        of SEARCH, it is about 20 % faster than my previous improved
        version, and is 10 times faster in the case where the string
        being searched for starts with a space. It is also 140 bytes
        smaller than the old implimentation.

comment;

hex
CODE SEARCH     ( sadr slen dadr dcnt -- offset found? )
  pop cx   pop di
  pop bx   pop ax   push di
  push es   mov es, sseg   push si   push bp   mov si, ax
  dec bx
  mov dx, bx    cmp caps # 0
  0= if    mov bp, # 0
     else  mov bp, # $2020
     then
  begin
      cmp bx, cx
  <= while
      begin
          mov al, 0 [si+bx]   mov ah, es: 0 [di+bx]
          or ax, bp   cmp ah, al
      0= while  dec bx  0< if     pop bp   pop si   pop es
                                  pop dx   sub di, dx
                                  push di  mov ax, # $FFFF   1push
                          then
      repeat
      inc di   dec cx   mov bx, dx
  repeat
  pop bp      pop si       pop es
  pop dx      sub di, dx   push di
  sub ax, ax  1push
  end-code

decimal

comment:

: DELETE   ( buffer size count -- )
   OVER MIN >R  R@ - ( left over )  DUP 0>
   IF  2DUP SWAP DUP R@ + -ROT SWAP CMOVE  THEN  + R> BLANK ;

: INSERT   ( string length buffer size -- )
   ROT OVER MIN >R  R@ - ( left over )
   OVER DUP R@ +  ROT CMOVE>   R> CMOVE  ;

: REPLACE   ( string length buffer size -- )  ROT MIN CMOVE ;

comment;