lib/expr: fix unary minus

For some reason, I've mistakenly disabled tests in test_expr without noticing
and I also broke "-123" parsing. Fixed.

apps/basic/main.asm

@@ -224,7 +224,6 @@ basPRINT:
 	ex	de, hl
 	call	parseExpr
 	jr	nz, .parseError
-	push	ix \ pop de
 	ld	hl, SCRATCHPAD
 	call	fmtDecimalS
 	call	printstr
@@ -254,7 +253,6 @@ basGOTO:
 	ex	de, hl
 	call	parseExpr
 	ret	nz
-	push	ix \ pop de
 	call	bufFind
 	jr	nz, .notFound
 	push	ix \ pop de
@@ -317,7 +315,7 @@ basINPUT:
 	call	rdSep
 	call	stdioReadLine
 	call	parseExpr
-	ld	(VAR_TBL), ix
+	ld	(VAR_TBL), de
 	call	printcrlf
 	cp	a		; ensure Z
 	ret

apps/basic/parse.asm

@@ -42,7 +42,6 @@ parseTruth:
 .simple:
 	call	parseExpr
 	jr	nz, .end
-	push	ix \ pop de
 	ld	a, d
 	or	e
 	jr	.success
@@ -132,12 +131,12 @@ parseTruth:
 ; place their corresponding values in HL and DE.
 .parseLeftRight:
 	; let's start with HL
+	push	de		; --> lvl 1
 	call	parseExpr
+	pop	hl		; <-- lvl 1, orig DE
 	ret	nz
-	push	ix		; --> lvl 1. save (HL) value in stack.
-	ex	de, hl
-	call	parseExpr
-	ret	nz
-	push	ix \ pop de
-	pop	hl		; <-- lvl 1. restore.
+	push	de		; --> lvl 1. save HL value in stack.
+	; Now, for DE. (DE) is now in HL
+	call	parseExpr	; DE in place
+	pop	hl		; <-- lvl 1. restore saved HL
 	ret

apps/basic/tok.asm

@@ -85,11 +85,13 @@ rdWord:
 ; Read word from HL in SCRATCHPAD and then intepret that word as an expression.
 ; Put the result in IX.
 ; Z for success.
+; TODO: put result in DE
 rdExpr:
 	ld	de, SCRATCHPAD
 	call	rdWord
 	push	hl
 	ex	de, hl
 	call	parseExpr
+	push	de \ pop ix
 	pop	hl
 	ret

apps/basic/var.asm

@@ -52,10 +52,9 @@ varTryAssign:
 	call	rdWord
 	ex	de, hl
 	; Now, evaluate that expression now in (HL)
-	call	parseExpr	; --> number in IX
+	call	parseExpr	; --> number in DE
 	jr	nz, .exprErr
 	pop	af	; <-- lvl 4
-	push	ix \ pop de	; send number to DE
 	call	varAssign
 	xor	a	; ensure Z
 .end:

apps/lib/expr.asm

@@ -11,19 +11,18 @@
 ;
 ; *** Code ***
 ;
-; Parse expression in string at (HL) and returns the result in IX.
+
+; Parse expression in string at (HL) and returns the result in DE.
 ; **This routine mutates (HL).**
 ; We expect (HL) to be disposable: we mutate it to avoid having to make a copy.
 ; Sets Z on success, unset on error.
-; TODO: the IX output register is a bit awkward. Nearly everywhere, I need
-;       to push \ pop that thing. See if we could return the result in DE
-;       instead.
 parseExpr:
-	push	de
+	push	ix
 	push	hl
 	call	_parseExpr
+	push	ix \ pop de
 	pop	hl
-	pop	de
+	pop	ix
 	ret
 
 _parseExpr:
@@ -97,25 +96,29 @@ _findAndSplit:
 ; parse expression on the left (HL) and the right (DE) and put the results in
 ; HL (left) and DE (right)
 _resolveLeftAndRight:
-	; special case: is (HL) zero? If yes, it means that our left operand
-	; is empty. consider it as 0
-	ld	ix, 0		; pre-set to 0
 	ld	a, (hl)
 	or	a
-	jr	z, .skip
+	jr	z, .noleft
 	; Parse left operand in (HL)
+	push	de		; --> lvl 1
 	call	parseExpr
+	pop	hl		; <-- lvl 1, orig DE
 	ret	nz		; return immediately if error
-.skip:
+.parseright:
 	; Now we have parsed everything to the left and we have its result in
-	; IX. What we need to do now is the same thing on (DE) and then apply
-	; the + operator. Let's save IX somewhere and parse this.
-	ex	de, hl	; right expr now in HL
-	push	ix	; --> lvl 1
-	call	parseExpr
-	pop	hl	; <-- lvl 1. left
-	push	ix \ pop de	; right
+	; DE. What we need to do now is the same thing on (DE) and then apply
+	; the + operator. Let's save DE somewhere and parse this.
+	push	de	; --> lvl 1
+	; right expr in (HL)
+	call	parseExpr	; DE is set
+	pop	hl	; <-- lvl 1. left value
 	ret		; Z is parseExpr's result
+.noleft:
+	; special case: is (HL) zero? If yes, it means that our left operand
+	; is empty. consider it as 0
+	ex	de, hl	; (DE) goes in (HL) for .parseright
+	ld	de, 0
+	jr	.parseright
 
 ; Routines in here all have the same signature: they take two numbers, DE (left)
 ; and IX (right), apply the operator and put the resulting number in DE.

apps/zasm/avr.asm

@@ -643,14 +643,15 @@ _readK8:
 	jr	_readExpr
 
 _readDouble:
-	push	ix
+	push	de
 	call	parseExpr
 	jr	nz, .end
-	push	ix \ pop bc
+	ld	b, d
+	ld	c, e
 	; BC is already set. For good measure, let's set A to BC's MSB
 	ld	a, b
 .end:
-	pop	ix
+	pop	de
 	ret
 
 _readk7:
@@ -663,13 +664,12 @@ _readk7:
 	; truncation checks might falsely fail.
 	call	zasmIsFirstPass
 	jr	z, .end
-	; IX contains an absolute value. Turn this into a -64/+63 relative
+	; DE contains an absolute value. Turn this into a -64/+63 relative
 	; value by subtracting PC from it. However, before we do that, let's
 	; add 0x7f to it, which we'll remove later. This will simplify bounds
 	; checks. (we use 7f instead of 3f because we deal in bytes here, not
 	; in words)
-	push	ix \ pop hl
-	ld	de, 0x7f
+	ld	hl, 0x7f
 	add	hl, de		; Carry cleared
 	ex	de, hl
 	call	zasmGetPC	; --> HL
@@ -706,6 +706,7 @@ _readR4:
 ; read a rXX argument and return register number in A.
 ; Set Z for success.
 _readR5:
+	push	de
 	push	ix
 	ld	a, (hl)
 	call	upcase
@@ -714,43 +715,44 @@ _readR5:
 	inc	hl
 	call	parseDecimal
 	jr	nz, .end
+	push	ix \ pop de
 	ld	a, 31
-	call	_IX2A
+	call	_DE2A
 .end:
 	pop	ix
+	pop	de
 	ret
 
-; Put IX's LSB into A and, additionally, ensure that the new value is <=
+; Put DE's LSB into A and, additionally, ensure that the new value is <=
 ; than what was previously in A.
 ; Z for success.
-_IX2A:
-	push	ix \ pop hl
-	cp	l
-	jp	c, unsetZ	; A < L
-	ld	a, h
+_DE2A:
+	cp	e
+	jp	c, unsetZ	; A < E
+	ld	a, d
 	or	a
 	ret	nz		; should be zero
-	ld	a, l
+	ld	a, e
 	; Z set from "or a"
 	ret
 
 ; Read expr and return success only if result in under number given in A
 ; Z for success
 _readExpr:
-	push	ix
+	push	de
 	push	bc
 	ld	b, a
 	call	parseExpr
 	jr	nz, .end
 	ld	a, b
-	call	_IX2A
+	call	_DE2A
 	jr	nz, .end
 	or	c
 	ld	c, a
 	cp	a		; ensure Z
 .end:
 	pop	bc
-	pop	ix
+	pop	de
 	ret
 
 ; Parse one of the following: X, Y, Z, X+, Y+, Z+, -X, -Y, -Z.

apps/zasm/directive.asm

@@ -40,6 +40,7 @@ dirHandlers:
 	.dw	handleBIN
 
 handleDB:
+	push	de
 	push	hl
 .loop:
 	call	readWord
@@ -49,18 +50,19 @@ handleDB:
 	jr	z, .stringLiteral
 	call	parseExpr
 	jr	nz, .badarg
-	push	ix \ pop hl
-	ld	a, h
+	ld	a, d
 	or	a		; cp 0
 	jr	nz, .overflow	; not zero? overflow
-	ld	a, l
+	ld	a, e
 	call	ioPutB
 	jr	nz, .ioError
 .stopStrLit:
 	call	readComma
 	jr	z, .loop
 	cp	a		; ensure Z
+.end:
 	pop	hl
+	pop	de
 	ret
 .ioError:
 	ld	a, SHELL_ERR_IO_ERROR
@@ -74,9 +76,8 @@ handleDB:
 .overflow:
 	ld	a, ERR_OVFL
 .error:
-	call	unsetZ
-	pop	hl
-	ret
+	or	a		; unset Z
+	jr	.end
 
 .stringLiteral:
 	ld	a, (hl)
@@ -89,6 +90,7 @@ handleDB:
 	jr	.stringLiteral
 
 handleDW:
+	push	de
 	push	hl
 .loop:
 	call	readWord
@@ -96,17 +98,18 @@ handleDW:
 	ld	hl, scratchpad
 	call	parseExpr
 	jr	nz, .badarg
-	push	ix \ pop hl
-	ld	a, l
+	ld	a, e
 	call	ioPutB
 	jr	nz, .ioError
-	ld	a, h
+	ld	a, d
 	call	ioPutB
 	jr	nz, .ioError
 	call	readComma
 	jr	z, .loop
 	cp	a		; ensure Z
+.end:
 	pop	hl
+	pop	de
 	ret
 .ioError:
 	ld	a, SHELL_ERR_IO_ERROR
@@ -117,9 +120,8 @@ handleDW:
 .badarg:
 	ld	a, ERR_BAD_ARG
 .error:
-	call	unsetZ
-	pop	hl
-	ret
+	or	a		; unset Z
+	jr	.end
 
 handleEQU:
 	call	zasmIsLocalPass	; Are we in local pass? Then ignore all .equ.
@@ -149,7 +151,6 @@ handleEQU:
 	call	parseExpr
 	jr	nz, .badarg
 	ld	hl, DIREC_SCRATCHPAD
-	push	ix \ pop de
 	; Save value in "@" special variable
 	ld	(DIREC_LASTVAL), de
 	call	symRegisterConst	; A and Z set
@@ -179,14 +180,17 @@ handleEQU:
 	jp	readWord
 
 handleORG:
+	push	de
 	call	readWord
 	jr	nz, .badfmt
 	call	parseExpr
 	jr	nz, .badarg
-	push	ix \ pop hl
+	ex	de, hl
 	ld	(DIREC_LASTVAL), hl
 	call	zasmSetOrg
 	cp	a		; ensure Z
+.end:
+	pop	de
 	ret
 .badfmt:
 	ld	a, ERR_BAD_FMT
@@ -194,31 +198,28 @@ handleORG:
 .badarg:
 	ld	a, ERR_BAD_ARG
 .error:
-	call	unsetZ
-	ret
+	or	a		; unset Z
+	jr	.end
 
 handleFIL:
 	call	readWord
 	jr	nz, .badfmt
 	call	parseExpr
 	jr	nz, .badarg
-	push	bc	; --> lvl 1
-	push	ix \ pop bc
-	ld	a, b
+	ld	a, d
 	cp	0xd0
 	jr	nc, .overflow
 .loop:
-	ld	a, b
-	or	c
+	ld	a, d
+	or	e
 	jr	z, .loopend
 	xor	a
 	call	ioPutB
 	jr	nz, .ioError
-	dec	bc
+	dec	de
 	jr	.loop
 .loopend:
 	cp	a	; ensure Z
-	pop	bc	; <-- lvl 1
 	ret
 .ioError:
 	ld	a, SHELL_ERR_IO_ERROR
@@ -230,11 +231,11 @@ handleFIL:
 	ld	a, ERR_BAD_ARG
 	jp	unsetZ
 .overflow:
-	pop	bc	; <-- lvl 1
 	ld	a, ERR_OVFL
 	jp	unsetZ
 
 handleOUT:
+	push	de
 	push	hl
 	; Read our expression
 	call	readWord
@@ -244,10 +245,9 @@ handleOUT:
 	ld	hl, scratchpad
 	call	parseExpr
 	jr	nz, .badarg
-	push	ix \ pop hl
-	ld	a, h
+	ld	a, d
 	out	(ZASM_DEBUG_PORT), a
-	ld	a, l
+	ld	a, e
 	out	(ZASM_DEBUG_PORT), a
 	jr	.end
 .badfmt:
@@ -256,9 +256,10 @@ handleOUT:
 .badarg:
 	ld	a, ERR_BAD_ARG
 .error:
-	call	unsetZ
+	or	a		; unset Z
 .end:
 	pop	hl
+	pop	de
 	ret
 
 handleINC:

apps/zasm/instr.asm

@@ -146,7 +146,7 @@ parseIXY:
 ; any argspec (A == 0 means arg is empty). A return value of 0xff means an
 ; error.
 ;
-; If the parsed argument is a number constant, 'N' is returned and IX contains
+; If the parsed argument is a number constant, 'N' is returned and DE contains
 ; the value of that constant.
 parseArg:
 	call	strlen
@@ -154,13 +154,8 @@ parseArg:
 	ret	z		; empty string? A already has our result: 0
 
 	push	bc
-	push	de
 	push	hl
 
-	; We always initialize IX to zero so that non-numerical args end up with
-	; a clean zero.
-	ld	ix, 0
-
 	ld	de, argspecTbl
 	; DE now points the the "argspec char" part of the entry, but what
 	; we're comparing in the loop is the string next to it. Let's offset
@@ -181,7 +176,7 @@ parseArg:
 	; (HL) has no parens
 	call	.maybeParseExpr
 	jr	nz, .nomatch
-	; We have a proper number in no parens. Number in IX.
+	; We have a proper number in no parens. Number in DE.
 	ld	a, 'N'
 	jr	.end
 .withParens:
@@ -208,23 +203,20 @@ parseArg:
 .parseNumberInParens:
 	call	.maybeParseExpr
 	jr	nz, .nomatch
-	; We have a proper number in parens. Number in IX
-	; is '-' in B? if yes, we need to negate the low part of IX
+	; We have a proper number in parens. Number in DE
+	; is '-' in B? if yes, we need to negate the low part of DE
 	ld	a, b
 	cp	'-'
-	jr	nz, .dontNegateIX
-	; we need to negate the low part of IX
+	jr	nz, .dontNegateDE
+	; we need to negate the low part of DE
 	; TODO: when parsing routines properly support unary negative numbers,
 	; We could replace this complicated scheme below with a nice hack where
 	; we start parsing our displacement number at the '+' and '-' char.
 
-	; HL isn't needed anymore and can be destroyed.
-	push	ix \ pop hl
-	ld	a, l
+	ld	a, e
 	neg
-	ld	l, a
-	push	hl \ pop ix
-.dontNegateIX:
+	ld	e, a
+.dontNegateDE:
 	ld	a, c	; M, x, or y
 	jr	.end
 .nomatch:
@@ -235,9 +227,13 @@ parseArg:
 	; found the matching argspec row. Our result is one byte left of DE.
 	dec	de
 	ld	a, (de)
+
+	; When we have non-numerical args, we set DE to zero to have a clean
+	; result.
+	ld	de, 0
+
 .end:
 	pop	hl
-	pop	de
 	pop	bc
 	ret
 
@@ -247,6 +243,7 @@ parseArg:
 	; harmless, but in some cases it causes false failures. For example,
 	; a "-" operator can cause is to falsely overflow and generate
 	; truncation error.
+	ld	de, 0			; in first pass, return a clean zero
 	call	zasmIsFirstPass
 	ret	z
 	jp	parseExpr
@@ -817,27 +814,18 @@ spitUpcode:
 	ld	(INS_UPCODE+2), a
 	ret
 
-; Parse argument in (HL) and place it in (DE)
-; DE is not preserved
+; Parse argument in (HL) and place it in (IX)
 ; Sets Z on success, reset on error.
 processArg:
 	call	parseArg
 	cp	0xff
 	jr	z, .error
-	ld	(de), a
-	; When A is a number, IX is set with the value of that number. Because
+	ld	(ix), a
+	; When A is a number, DE is set with the value of that number. Because
 	; We don't use the space allocated to store those numbers in any other
-	; occasion, we store IX there unconditonally, LSB first.
-	inc	de
-	ex	(sp), ix	; (SP) is kept in IX and will be restored
-	ex	(sp), hl	; old HL is on (SP)
-	ld	a, l
-	ld	(de), a
-	inc	de
-	ld	a, h
-	ld	(de), a
-	ex	(sp), hl	; restore old HL from (SP)
-	ex	(sp), ix	; restore old (SP) from IX
+	; occasion, we store DE there unconditonally, LSB first.
+	ld	(ix+1), e
+	ld	(ix+2), d
 	cp	a		; ensure Z
 	ret
 .error:
@@ -860,14 +848,14 @@ parseInstruction:
 	ld	(INS_CURARG2), a
 	call	readWord
 	jr	nz, .nomorearg
-	ld	de, INS_CURARG1
+	ld	ix, INS_CURARG1
 	call	processArg
 	jr	nz, .end	; A is set to error, Z is unset
 	call	readComma
 	jr	nz, .nomorearg
 	call	readWord
 	jr	nz, .badfmt
-	ld	de, INS_CURARG2
+	ld	ix, INS_CURARG2
 	call	processArg
 	jr	nz, .end	; A is set to error, Z is unset
 .nomorearg:

tools/emul/runbin/runbin.c

@@ -6,9 +6,15 @@
  * until it halts. The return code is the value of the register A at halt time.
  */
 
+static void iowr_stderr(uint8_t val)
+{
+    fputc(val, stderr);
+}
+
 int main()
 {
     Machine *m = emul_init();
+    m->iowr[0] = iowr_stderr;
     // read stdin in mem
     int i = 0;
     int c = getchar();
@@ -22,6 +28,7 @@ int main()
         return 1;
     }
     emul_loop();
+    if (m->cpu.R1.wr.HL)
     return m->cpu.R1.br.A;
 }
 

tools/tests/unit/common.asm

@@ -0,0 +1,62 @@
+; *** requirements ***
+; ascii.h
+; core
+; stdio
+; lib/ari
+; lib/fmt
+
+testNum:	.db 1
+
+STDIO_PUTC:
+	out	(0), a
+	cp	a
+	ret
+
+STDIO_GETC:
+	jp	unsetZ
+
+assertZ:
+	ret	z
+	ld	hl, .msg
+	call	printstr
+	jp	fail
+.msg:
+	.db	"Z not set", CR, LF, 0
+
+assertNZ:
+	ret	nz
+	ld	hl, .msg
+	call	printstr
+	jp	fail
+.msg:
+	.db	"Z set", CR, LF, 0
+
+; Assert that HL == DE
+assertEQW:
+	ld	a, h
+	cp	d
+	jr	nz, .fail
+	ld	a, l
+	cp	e
+	ret	z
+.fail:
+	call	printHexPair
+	call	printcrlf
+	ex	de, hl
+	call	printHexPair
+	call	printcrlf
+	ld	hl, .msg
+	call	printstr
+	jp	fail
+.msg:
+	.db	"HL != DE", CR, LF, 0
+
+nexttest:
+	ld	a, (testNum)
+	inc	a
+	ld	(testNum), a
+	ret
+
+fail:
+	ld	a, (testNum)
+	halt

tools/tests/unit/runtests.sh

@@ -11,7 +11,7 @@ APPS="${BASE}/apps"
 
 chk() {
     echo "Running test $1"
-    if ! ${ZASM} "${KERNEL}" "${APPS}" < $1 | ${RUNBIN}; then
+    if ! ${ZASM} "${KERNEL}" "${APPS}" common.asm < $1 | ${RUNBIN}; then
         echo "failed with code ${PIPESTATUS[1]}"
         exit 1
     fi
@@ -22,7 +22,7 @@ if [ ! -z $1 ]; then
     exit 0
 fi
 
-for fn in *.asm; do
+for fn in test_*.asm; do
     chk "${fn}"
 done
 

tools/tests/unit/test_basic_parse.asm

@@ -1,5 +1,6 @@
 jp	test
 
+.inc "ascii.h"
 .inc "core.asm"
 .inc "str.asm"
 .inc "lib/util.asm"
@@ -8,6 +9,9 @@ jp	test
 .equ	EXPR_PARSE	parseLiteral
 .inc "lib/expr.asm"
 .inc "basic/parse.asm"
+.inc "lib/fmt.asm"
+.inc "stdio.asm"
+.inc "common.asm"
 
 test:
 	ld	sp, 0xffff
@@ -55,21 +59,21 @@ testParseThruth:
 
 .true:
 	call	parseTruth
-	jp	nz, fail
+	call	assertZ
 	or	a
-	jp	z, fail
+	call	assertNZ
 	jp	nexttest
 
 .false:
 	call	parseTruth
-	jp	nz, fail
+	call	assertZ
 	or	a
-	jp	nz, fail
+	call	assertZ
 	jp	nexttest
 
 .error:
 	call	parseTruth
-	jp	z, fail
+	call	assertNZ
 	jp	nexttest
 
 .t1:	.db	"42", 0
@@ -88,17 +92,4 @@ testParseThruth:
 .f6:	.db	"2<=1", 0
 .e1:	.db	"foo", 0
 
-testNum:	.db 1
-
-nexttest:
-	ld	a, (testNum)
-	inc	a
-	ld	(testNum), a
-	ret
-
-fail:
-	ld	a, (testNum)
-	halt
-
-; used as RAM
-sandbox:
+STDIO_RAMSTART:

tools/tests/unit/test_core.asm

@@ -5,8 +5,14 @@
 
 jp	test
 
+.inc "ascii.h"
+.inc "core.asm"
+.inc "lib/ari.asm"
+.inc "lib/fmt.asm"
+.inc "stdio.asm"
+.inc "common.asm"
+
 dummyLabel:
-testNum:	.db 1
 
 .equ	dummyLabel	0x42
 
@@ -37,37 +43,25 @@ test:
 	call	nexttest
 
 	; Test that .equ can override label
-	ld	a, 0x42
+	ld	de, 0x42
 	ld	hl, dummyLabel
-	cp	l
-	jp	nz, fail
+	call	assertEQW
 	call	nexttest
 
 	; test that "@" is updated by a .org directive
 	ld	hl, AFTER_ORG
 	ld	de, 0x1234
-	or	a	; clear carry
-	sbc	hl, de
-	jp	nz, fail
+	call	assertEQW
 	call	nexttest
 
 	; test that AND affects the Z flag
 	ld	a, 0x69
 	and	0x80
-	jp	nz, fail
+	call	assertZ
 	call	nexttest
 
 	; success
 	xor	a
 	halt
 
-nexttest:
-	ld	a, (testNum)
-	inc	a
-	ld	(testNum), a
-	ret
-
-fail:
-	ld	a, (testNum)
-	halt
-
+STDIO_RAMSTART:

tools/tests/unit/test_expr.asm

@@ -9,10 +9,12 @@
 
 jp	test
 
+.inc "ascii.h"
 .inc "core.asm"
 .inc "str.asm"
 .inc "lib/util.asm"
 .inc "lib/ari.asm"
+.inc "lib/fmt.asm"
 .inc "zasm/util.asm"
 .inc "zasm/const.asm"
 .inc "lib/parse.asm"
@@ -21,6 +23,9 @@ jp	test
 .inc "zasm/symbol.asm"
 .equ	EXPR_PARSE	parseNumberOrSymbol
 .inc "lib/expr.asm"
+.equ	STDIO_RAMSTART	SYM_RAMEND
+.inc "stdio.asm"
+.inc "common.asm"
 
 ; Pretend that we aren't in first pass
 zasmIsFirstPass:
@@ -29,8 +34,6 @@ zasmIsFirstPass:
 zasmGetPC:
 	ret
 
-testNum:	.db 1
-
 s1:		.db "2+2", 0
 s2:		.db "0x4001+0x22", 0
 s3:		.db "FOO+BAR", 0
@@ -44,29 +47,22 @@ sBAR:		.db "BAR", 0
 test:
 	ld	sp, 0xffff
 
+	; New-style tests
+	call	testParseExpr
+
 	; Old-style tests, not touching them now.
 	ld	hl, s1
 	call	parseExpr
-	jp	nz, fail
-	push	ix \ pop hl
-	ld	a, h
-	or	a
-	jp	nz, fail
-	ld	a, l
-	cp	4
-	jp	nz, fail
+	call	assertZ
+	ld	hl, 4
+	call	assertEQW
 	call	nexttest
 
 	ld	hl, s2
 	call	parseExpr
-	jp	nz, fail
-	push	ix \ pop hl
-	ld	a, h
-	cp	0x40
-	jp	nz, fail
-	ld	a, l
-	cp	0x23
-	jp	nz, fail
+	call	assertZ
+	ld	hl, 0x4023
+	call	assertEQW
 	call	nexttest
 
 	; before the next test, let's set up FOO and BAR symbols
@@ -82,54 +78,32 @@ test:
 
 	ld	hl, s3
 	call	parseExpr
-	jp	nz, fail
-	push	ix \ pop hl
-	ld	a, h
-	cp	0x40
-	jp	nz, fail
-	ld	a, l
-	cp	0x20
-	jp	nz, fail
+	call	assertZ
+	ld	hl, 0x4020
+	call	assertEQW
 	call	nexttest
 
 	ld	hl, s4
 	call	parseExpr
-	jp	nz, fail
-	push	ix \ pop hl
-	ld	a, h
-	or	a
-	jp	nz, fail
-	ld	a, l
-	cp	0x60
-	jp	nz, fail
+	call	assertZ
+	ld	hl, 0x60
+	call	assertEQW
 	call	nexttest
 
 	ld	hl, s5
 	call	parseExpr
-	jp	nz, fail
-	push	ix \ pop hl
-	ld	a, h
-	cp	0x3f
-	jp	nz, fail
-	ld	a, l
-	cp	0xfd
-	jp	nz, fail
+	call	assertZ
+	ld	hl, 0x3ffd
+	call	assertEQW
 	call	nexttest
 
 	ld	hl, s6
 	call	parseExpr
-	jp	nz, fail
-	push	ix \ pop hl
-	ld	a, h
-	cp	0x40
-	jp	nz, fail
-	ld	a, l
-	cp	0x80
-	jp	nz, fail
+	call	assertZ
+	ld	hl, 0x4080
+	call	assertEQW
 	call	nexttest
 
-	; New-style tests
-	call	testParseExpr
 	; success
 	xor	a
 	halt
@@ -151,20 +125,18 @@ testParseExpr:
 	call	.testEQ
 	ld	iy, .t8
 	call	.testEQ
+	ld	iy, .t9
+	call	.testEQ
 	ret
 
 .testEQ:
 	push	iy \ pop hl
 	inc	hl \ inc hl
 	call	parseExpr
-	jp	nz, fail
-	push	ix \ pop de
-	ld	a, e
-	cp	(iy)
-	jp	nz, fail
-	ld	a, d
-	cp	(iy+1)
-	jp	nz, fail
+	call	assertZ
+	ld	l, (iy)
+	ld	h, (iy+1)
+	call	assertEQW
 	jp	nexttest
 
 .t1:
@@ -191,13 +163,6 @@ testParseExpr:
 .t8:
 	.dw	0xffff
 	.db	"-1", 0
-
-nexttest:
-	ld	a, (testNum)
-	inc	a
-	ld	(testNum), a
-	ret
-
-fail:
-	ld	a, (testNum)
-	halt
+.t9:
+	.dw	10
+	.db	"2*3+4", 0