String matching: Difference between revisions

=={{header|Z80 Assembly}}==

{{trans|MIPS Assembly}}

<lang z80>InString:

;input: hl = pointer to string 1

; de = pointer to string 2

; assumes len(hl) <= len(de)

; output in BC

;clobbers: ix

push de

pop ix ;back up de into ix

ld bc,0 ;our return value

InString_again:

ld a,(hl)

or a

ret z

ld a,(de)

or a

ret z

cp (hl)

jr nz,InString_noMatch

inc de

jr InString_overhead

InString_noMatch:

push ix

pop de

inc bc

InString_overhead:

inc hl

jr InString_again</lang>

{{out}}

<lang z80>org &1000

ld hl,TestString

ld de,Test1 ;recompiled with each test string and tested it

call InString

ld a,c

call ShowHex

ret

TestString:

db "abcdefg",0

Test1:

db "abc",0 ;returns 0

Test2:

db "def",0 ;returns 3

Test3:

db "efg",0 ;returns 4

Test4:

db "z",0 ;returns 7</lang>