zasm: make each token type parse the remaining of line directly

apps/zasm/instr.asm

@@ -415,14 +415,14 @@ matchArg:
 	dec	hl
 	ret
 
-; Compare primary row at (DE) with ID at (tokInstr+1). Sets Z flag if there's a
+; Compare primary row at (DE) with ID at (token+1). Sets Z flag if there's a
 ; match, reset if not.
 matchPrimaryRow:
 	push	hl
 	push	ix
 	ld	ixh, d
 	ld	ixl, e
-	ld	a, (tokInstr+1)
+	ld	a, (token+1)
 	cp	(ix)
 	jr	nz, .end
 	; name matches, let's see the rest
@@ -747,9 +747,23 @@ getUpcode:
 	pop	ix
 	ret
 
-; Parse tokenizes argument in (HL), parses it and place it in (DE)
+; Parse next argument in string (HL) and place it in (DE)
 ; Sets Z on success, reset on error.
 processArg:
+	push	de
+	call	toWord
+	xor	a
+	ld	de, scratchpad
+	ld	(de), a
+	ld	a, 8
+	call	readWord
+	pop	de
+	; Read word is in scratchpad, (DE) is back to initial value, HL is
+	; properly advanced. Now, let's push that HL value and replace it with
+	; (scratchpad) so that we can parse that arg.
+	push	hl
+	ld	hl, scratchpad
+
 	call	parseArg
 	cp	0xff
 	jr	z, .error
@@ -764,22 +778,21 @@ processArg:
 	ld	a, ixh
 	ld	(de), a
 	cp	a		; ensure Z is set
+	pop	hl
 	ret
 .error:
 	call	JUMP_UNSETZ
+	pop	hl
 	ret
 
-; Parse instruction specified in A (I_* const) with args in (tokArg1) and
-; (tokArg2) and write resulting opcode(s) in (curUpcode). Returns the number of
-; bytes written in A.
+; Parse instruction specified in A (I_* const) with args in (HL) and write
+; resulting opcode(s) in (curUpcode). Returns the number of bytes written in A.
 parseInstruction:
 	push	hl
 	push	de
-	ld	hl, tokArg1
 	ld	de, curArg1
 	call	processArg
 	jr	nz, .error
-	ld	hl, tokArg2
 	ld	de, curArg2
 	call	processArg
 	jr	nz, .error

apps/zasm/main.asm

@@ -33,21 +33,17 @@ parseLine:
 	call	gotoNextNotBlankLine
 	jr	nz, .error
 	push	de
-	ld	de, tokInstr
+	ld	de, token
 	call	tokenize
-	ld	a, (tokInstr)	; TOK_*
+	pop	de
+	ld	a, (token)	; TOK_*
 	cp	TOK_BAD
 	jr	z, .error
-	ld	de, tokArg1
-	call	tokenizeInstrArg
-	ld	de, tokArg2
-	call	tokenizeInstrArg
-	pop	de
 	cp	TOK_INSTR
 	jr	z, .instr
 	jr	.error		; directive not supported yet
 .instr:
-	ld	a, (tokInstr+1)	; I_*
+	ld	a, (token+1)	; I_*
 	call	parseInstruction
 	or	a	; is zero?
 	jr	z, .error
@@ -67,10 +63,8 @@ parseLine:
 
 ; *** Variables ***
 
-tokInstr:
+token:
 	.fill	5
-tokArg1:
-	.fill	9
-tokArg2:
-	.fill	9
 
+scratchpad:
+	.fill	0x20

apps/zasm/tok.asm

@@ -47,16 +47,6 @@ tokenize:
 	ld	(de), a
 	ret
 
-tokenizeInstrArg:
-	push	af
-	xor	a
-	ld	(de), a
-	call	toWord
-	ld	a, 8
-	call	readWord
-	pop	af
-	ret
-
 ; Sets Z is A is ';', CR, LF, or null.
 isLineEndOrComment:
 	cp	';'