Apple-2-SW
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prodos-path
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shave bytes, dedupe

This commit is contained in:
Joshua Bell 2019-01-09 17:17:16 -08:00
parent 7747cd27cc
commit 0d6f42d22f
1 changed files with 20 additions and 25 deletions
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@ -129,7 +129,13 @@ CASE_MASK = $DF
.res $2100 - *, 0
.proc handler
ptr := $06
ptr := $06 ; pointer into VPATH
tptr := $08 ; pointer into TOKEN_NAME_TABLE
lda VPATH1
sta ptr
lda VPATH1+1
sta ptr+1
;; Check for this command, character by character.
page_num9 := *+2 ; address needing updating
@ -189,20 +195,20 @@ check_if_token:
;; Check if it's a BASIC token. Based on the AppleSoft BASIC source.
;; Point ptr at TOKEN_NAME_TABLE less one page (will advance below)
;; Point tptr at TOKEN_NAME_TABLE less one page (will advance below)
lda #<(TOKEN_NAME_TABLE-$100)
sta ptr
sta tptr
lda #>(TOKEN_NAME_TABLE-$100)
sta ptr+1
sta tptr+1
;; These are immediately incremented
dex
ldy #$FF ; (ptr),y offset TOKEN_NAME_TABLE
ldy #$FF ; (tptr),y offset TOKEN_NAME_TABLE
;; Match loop
mloop: iny ; Advance through token table
bne :+
inc ptr+1
inc tptr+1
: inx
;; Check for match
@ -213,7 +219,7 @@ next_char:
;; NOTE: Does not skip over spaces, unlike BASIC tokenizer
sec ; Compare by subtraction..
sbc (ptr),Y
sbc (tptr),Y
beq mloop
cmp #$80 ; If only difference was the high bit
beq not_ours ; then it's end-of-token -- and a match!
@ -222,13 +228,13 @@ next_char:
next_token:
page_num12 := *+2 ; address needing updating
jsr skip_leading_spaces
sloop: lda (ptr),y ; Scan table looking for a high bit set
sloop: lda (tptr),y ; Scan table looking for a high bit set
iny
bne :+
inc ptr+1
inc tptr+1
: asl
bcc sloop ; High bit clear, keep looking
lda (ptr),y ; End of table?
lda (tptr),y ; End of table?
bne next_char ; Nope, check for a match
beq maybe_invoke
@ -241,21 +247,15 @@ not_ours:
;;; ============================================================
maybe_invoke:
lda VPATH1
sta ptr
lda VPATH1+1
sta ptr+1
;; Compose path
ldx #0
page_num14 := *+2 ; address needing updating
ldx path_buffer
ldy #1
page_num11 := *+2 ; address needing updating
: lda path_buffer+1,x
inx
: lda path_buffer,y
sta (ptr),y
iny
page_num14 := *+2 ; address needing updating
cpx path_buffer
dex
bne :-
lda #'/'
@ -405,11 +405,6 @@ done: clc
;;; --------------------------------------------------
;; Set path
set_path:
lda VPATH1
sta ptr
lda VPATH1+1
sta ptr+1
ldy #0
lda (ptr),y
tay