collapseos/apps/zasm/tok.asm
Virgil Dupras f9ae5ca46b zasm: simplify readWord calling
It always reads in the scratchpad with the same max size. No need for
DE-dancing anymore.
2019-05-01 14:19:43 -04:00

36 lines
687 B
NASM

; *** Requirements ***
; JUMP_UPCASE
; *** Consts ***
TOK_INSTR .equ 0x01
TOK_DIRECTIVE .equ 0x02
TOK_BAD .equ 0xff
; *** Code ***
; Parse line in (HL) and read the next token in BC. The token is written on
; two bytes (B and C). B is a token type (TOK_* constants) and C is an ID
; specific to that token type.
; Advance HL to after the read word.
; If no token matches, TOK_BAD is written to B
tokenize:
call toWord
call readWord
push hl ; Save advanced HL for later
ld hl, scratchpad
call getInstID
jr z, .instr
call getDirectiveID
jr z, .direc
; no match
ld b, TOK_BAD
jr .end
.instr:
ld b, TOK_INSTR
jr .end
.direc:
ld b, TOK_DIRECTIVE
.end:
ld c, a
pop hl
ret