mirror of
https://github.com/RevCurtisP/C02.git
synced 2024-11-25 21:33:44 +00:00
221 lines
8.7 KiB
Plaintext
221 lines
8.7 KiB
Plaintext
; C02 library string.h02 assembly language subroutines
|
|
; Requires external routines SETSRC and SETDST
|
|
; Requires the following RAM locations be defined
|
|
; external zero page byte pairs SRCPTR and DSTPTR
|
|
; and external bytes TEMP0 and TEMP1
|
|
|
|
SUBROUTINE STRING
|
|
|
|
;strapd(c, s) - Append charecter c to string s
|
|
;Args: A = Character to be appended
|
|
; X,Y = Pointer to string
|
|
;Affects N,Z
|
|
;Returns A,Y = New String Length
|
|
STRAPD: STA TEMP0 ;Save Character to Append
|
|
JSR STRLEN ;Get Length of String
|
|
BMI .RETFLS ;Return 255 if > 127
|
|
LDA TEMP0 ;Restore Character to Append
|
|
.APDLOP STA (SRCPTR),Y ;Store at End of String
|
|
BEQ .LENEND ;Exit if NUL
|
|
INY ;Increment Past New Character
|
|
LDA #0 ;Set Character to NUL
|
|
BEQ .APDLOP ;and Append to String
|
|
|
|
;strppd(c, s) - Prepend Charecter to String
|
|
;Args: A = Character to be appended
|
|
; X,Y = Pointer to string
|
|
;Sets: N,Z
|
|
;Returns A = Insterted Character
|
|
STRPPD: STA TEMP0 ;Save Character to Append
|
|
JSR STRLEN ;Get Length of String
|
|
BMI .RETFLS ;Return 255 if > 127
|
|
INY ;Bump up string length
|
|
TYA ;Push string length onto stack
|
|
PHA
|
|
.PPDLOP DEY ;Copy Preceding Chacter
|
|
LDA (SRCPTR),Y
|
|
INY ;into Currebt Position
|
|
STA (SRCPTR),Y
|
|
DEY ;Move to Preceding Position
|
|
BNE .PPDLOP ;and Loop
|
|
LDA TEMP0 ;Retrieve Character
|
|
STA (SRCPTR),Y ;and Store in Position 0
|
|
PLA ;Retrieve new string length
|
|
BEQ .RETORA ;Set Flags and Return`
|
|
|
|
;strcmp(&s) - Compare String (to Destination String)
|
|
;Requires: DSTPTR - Pointer to destination string
|
|
;Args: X,Y = Pointer to source string
|
|
;Sets: SRCPTR = Pointer to string
|
|
;Affects N,Z
|
|
;Returns A=$01 and C=1 if Destination > Source
|
|
; A=$00 and Z=1, C=1 if Destination = Source
|
|
; A=$FF and C=0 if Destination < Source
|
|
; Y=Position of first character that differs
|
|
STRCMP: JSR SETSRC ;Initialize Source String
|
|
.CMPLOP LDA (DSTPTR),Y ;Load Destination Character
|
|
CMP (SRCPTR),Y ;Compare Against Source Character
|
|
BNE .CMPEND ;If Equal
|
|
ORA (SRCPTR),Y ; OR with Source Character
|
|
BEQ .RETURN ; If Both are 0, Return 0
|
|
INY ; Increment Offset
|
|
BPL .CMPLOP ; and Loop if < 128
|
|
.CMPEND BCC .RETFLS ;If Source < Destination, Return $FF & Carry Clear
|
|
LDA #$01 ;Else Return 1 and Carry Set
|
|
.RETURN RTS
|
|
|
|
;strchr(c, &s) - Find First Occurance of Character in String
|
|
;Args: A = Character to look for
|
|
; X,Y = Pointer to string to search in
|
|
;Sets: SRCPTR = Pointer to string
|
|
; TEMP3 = Character being searched for
|
|
;Affects: N,Z
|
|
;Returns: A = Position in string, C=1 if found
|
|
; A = $FF, C=0 if not found
|
|
; Y = Position of last character scanned
|
|
STRCHR: JSR SETSRC ;Initialize Source String
|
|
STRCHA: STA TEMP3 ;Save Search Character (alternate entry point)
|
|
.CHRLOP LDA (SRCPTR),Y ;Get Next Character
|
|
BEQ .CLCFLS ;If NUL, Return $FF and Carry Clear
|
|
CMP TEMP3 ;Compare Character
|
|
BEQ .LENEND ;If Found, Return Index
|
|
INY ;Increment Counter and Loop if < 128
|
|
BPL .CHRLOP ;Else Return $FF and Carry Clear
|
|
.CLCFLS CLC ;Clear Carry
|
|
.RETFLS LDA #$FF ;Load -1 into Accumulater
|
|
RTS ;and Return
|
|
|
|
;strapd(c, &s) - Append Character to String
|
|
;Args: A = Character to Append
|
|
; X,Y = Pointer to String
|
|
;Sets: SRCPTR, SRCPTR+1 - Pointer to String
|
|
;strlen(&s) - Return Length of String
|
|
;Args: X,Y - Pointer to string
|
|
;Sets: SRCPTR = Pointer to source string
|
|
;Returns: A,Y = Length of string
|
|
; N,Z based on A
|
|
STRLEN: JSR SETSRC ;Initialize Source String
|
|
.LENLOP LDA (SRCPTR),Y ;Get Next Character
|
|
BEQ .LENEND ;If <> NUL
|
|
INY ; Increment Index
|
|
BPL .LENLOP ; and Loop if < 128
|
|
.LENEND TYA ;Transfer Index to Accumulator
|
|
.RETORA ORA #0 ;Set N and Z flags
|
|
RTS ;and Return
|
|
|
|
;strcpb(&s) - Copy String to System Buffer
|
|
STRCPB: JSR SETSRC ;Set Source Pointer to String Address
|
|
JSR SETDSB ;Set Destination Pointer to System Buffer
|
|
BVC STRCPA ;Execute String Copy
|
|
|
|
;strcat(&s) Concatenate String (to Destination String)
|
|
;Requires: DSTPTR - Pointer to destination string
|
|
;Args: X,Y = Pointer to source string
|
|
;Sets: SRCPTR = Pointer to source string
|
|
; TEMP3 = Length of source prior to concatenation
|
|
;Affects: C,N,Z
|
|
;Returns: A,Y = Total length of concatenated string
|
|
STRCAT: JSR SETSRC ;Initialize Source String
|
|
.CATLOP LDA (DSTPTR),Y ;Find end of Destination String
|
|
BEQ .CATEND ;
|
|
INY ;
|
|
BPL .CATLOP ;
|
|
.CATEND STY TEMP3 ;Subtract Destination String Length
|
|
LDA SRCPTR ; from Source String Pointer
|
|
SEC
|
|
SBC TEMP3
|
|
STA SRCPTR
|
|
LDA SRCPTR+1
|
|
SBC #$00
|
|
STA SRCPTR+1
|
|
JMP .CPYLOP ;Execute String Copy
|
|
|
|
;strcpy(&s) - Copy String (to Destination String)
|
|
;Requires: DSTPTR - Pointer to destination string
|
|
;Args: X,Y = Pointer to source string
|
|
;Sets: SRCPTR = Pointer to source string
|
|
;Affects: N,Z
|
|
;Returns: A,Y = Number of characters copied
|
|
STRCPA: LDY #0 ;Alternate entry point
|
|
BEQ .CPYLOP ;for when Source already set
|
|
STRCPY: JSR SETSRC ;Initialize Source String
|
|
.CPYLOP LDA (SRCPTR),Y ;Get Character from Source String
|
|
STA (DSTPTR),Y ;Copy to Destination String
|
|
BEQ .CPYEND ;If <> NUL
|
|
INY ; Increment Index
|
|
BPL .CPYLOP ; and Loop if < 128
|
|
.CPYEND TYA ;Transfer Index to Accumulator
|
|
RTS ;and Return
|
|
|
|
;strcut(n, &s) - Copy from Position n to End of Source (into Destination)
|
|
;Requires: DSTPTR - Pointer to destination string
|
|
;Args: A = Starting position in start string
|
|
; X,Y = Pointer to source string
|
|
;Sets: SRCPTR = Pointer to specified position in source string
|
|
;Affects: N,Z
|
|
;Returns: A,Y = Length of copied string
|
|
STRCUT: JSR SETSRC ;Initialize Source String
|
|
CLC
|
|
ADC SRCPTR ;Move Source Pointer
|
|
STA SRCPTR ; to Specified Position in String
|
|
BCC .CPYLOP
|
|
INC SRCPTR+1
|
|
JMP .CPYLOP ;and Jump Into String Copy Loop
|
|
|
|
;strstr(&s) - Search for String (in Destination String)
|
|
;Requires: DSTPTR - Pointer to destination string
|
|
;Args: X,Y = Pointer to search string
|
|
;Sets: DSTPTR = Pointer to position in source string
|
|
; End of string if not found
|
|
; SRCPTR = Pointer to source string
|
|
; TEMP3 = Last position checked in destination string
|
|
;Affects: N,Z
|
|
;Returns: A = Position, C=1 if found
|
|
; A = $FF, C=0 if not found
|
|
; Y = Last position checked in source string
|
|
STRSTR: JSR SETSRC ;Initialize Source String
|
|
STY TEMP3 ;Initialize Position
|
|
.STRLOP LDY #$00; ;Initialize Compare Offset
|
|
LDA (DSTPTR),Y ;Get Start Character in Destination
|
|
BEQ .CLCFLS ;If NUL return $FF and Carry Clear
|
|
JSR .CMPLOP ;Jump into Compare Loop
|
|
BEQ .STREND ;If Not Equal
|
|
BMI .STRNXT ; If Source is Greater
|
|
LDA (SRCPTR),Y ; If at End of Source String
|
|
BEQ .STREND ; Return Current Position
|
|
.STRNXT INC TEMP3 ; Else Increment Position
|
|
BMI .CLCFLS ; If > 127 return $FF and Carry Clear
|
|
INC DSTPTR ; Increment Source Pointer
|
|
BNE .STRLOP
|
|
INC DSTPTR+1 ; If not End of Memory
|
|
BNE .STRLOP ; Loop
|
|
BEQ .CLCFLS ; Else return $FF and Carry Clear
|
|
.STREND SEC ;Else Set Carry
|
|
LDA TEMP3 ; Load Position
|
|
RTS ; and Return
|
|
|
|
;strrch(c, &s) - Find Last Occurance Character in String
|
|
;Args: A = Character to look for
|
|
; X,Y = Pointer to string to search in
|
|
;Sets: SRCPTR = Pointer to string
|
|
; TEMP3 = Character being searched for
|
|
;Affects: Y,C,N,Z
|
|
;Returns: A,X = Position of last occurance in string
|
|
; $FF if not found
|
|
; Y = Length of String
|
|
STRRCH: JSR SETSRC ;Initialize Source String
|
|
STA TEMP3; ;Save Search Character (alternate entry point)
|
|
LDX #$FF ;Initialize Position
|
|
.RCHLOP LDA (SRCPTR),Y ;Get Next Character
|
|
BEQ .RCHEND ;If NUL, Exit with Position
|
|
CMP TEMP3 ;Compare Character
|
|
BNE .RCHNXT ;If Found
|
|
TYA ; Store Counter
|
|
TAX
|
|
.RCHNXT INY ;Increment Counter
|
|
BPL .RCHLOP ; and Loop if < 128
|
|
.RCHEND TXA ;Copy Position to Accumulater
|
|
RTS ; and Return
|
|
|
|
ENDSUBROUTINE
|
|
|