emailler/ip65/parser.s
2018-02-23 16:36:05 +01:00

102 lines
2.2 KiB
ArmAsm

; text file parsing routines
; first call parser_init
; then call parser_skip_next
.export parser_init
.export parser_skip_next
.include "zeropage.inc"
.include "../inc/common.inc"
target_string = ptr1
search_string = ptr2
.bss
temp_ptr: .res 2
.data
get_next_byte:
current_string_ptr=get_next_byte+1
lda $ffff
inc current_string_ptr
bne :+
inc current_string_ptr+1
: pha
pla ; reload A so flags are set correctly
rts
.code
; set up a string for parsing
; inputs: AX = pointer to (null terminated) string to be parsed
; outputs: none
parser_init:
stax current_string_ptr
clc
rts
; advance pointer along till just past the next occurance of specified string
; inputs: AX= pointer to (null terminated) string to search for
; outputs: sec if search string not found
; if clc, AX = pointer to first byte after string specified
; if sec (i.e. no match found), pointer stays in same place
parser_skip_next:
stax search_string
ldax current_string_ptr
stax temp_ptr
@check_string:
ldy #0
ldax current_string_ptr
stax target_string
@check_next_char:
lda (search_string),y
beq @matched
cmp (target_string),y
bne @not_matched
iny
bne @check_next_char
@matched:
; now skip 'y' bytes
@skip_byte:
jsr get_next_byte
dey
bne @skip_byte
ldax current_string_ptr
clc
rts
@not_matched:
jsr get_next_byte
bne @check_string
ldax temp_ptr
stax current_string_ptr
sec
rts
; -- LICENSE FOR parser.s --
; The contents of this file are subject to the Mozilla Public License
; Version 1.1 (the "License"); you may not use this file except in
; compliance with the License. You may obtain a copy of the License at
; http://www.mozilla.org/MPL/
;
; Software distributed under the License is distributed on an "AS IS"
; basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
; License for the specific language governing rights and limitations
; under the License.
;
; The Original Code is ip65.
;
; The Initial Developer of the Original Code is Jonno Downes,
; jonno@jamtronix.com.
; Portions created by the Initial Developer are Copyright (C) 2009
; Jonno Downes. All Rights Reserved.
; -- LICENSE END --