6502-OS/util/string.s65

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;********************************************************************************
; @module string
; @type utility
; @details
; String utility
;********************************************************************************
.ifndef INCLUDE_STRING
INCLUDE_STRING = 1
.scope str
.code
.macro _StrfStoreArg arg
.if (.not .blank(arg))
.if .match(arg, x)
stx ARG4 + @N_ARGS
.elseif .match(arg, y)
sty ARG4 + @N_ARGS
.else
lda arg
sta ARG4 + @N_ARGS
.endif
@N_ARGS .set (@N_ARGS + 1)
.endif
.endmacro
;********************************************************************************
; @function Macro for passing arguments to strf
; @param fmt: Format string address
; @param out: Output string address
; @param x0-x9: Additional parameters
; @warning Addresses as additional paramteres must be passed like this `#<addr,#>addr`
; @modifies: A, X, Y
; @see strf
;********************************************************************************
.macro Strf fmt,out,x0,x1,x2,x3,x4,x5,x6,x7,x8,x9
@N_ARGS .set 0 ; @ so that it doesnt break cheap labels
lda #<fmt
sta ARG0
lda #>fmt
sta ARG1
lda #<out
sta ARG2
lda #>out
sta ARG3
_StrfStoreArg x0
_StrfStoreArg x1
_StrfStoreArg x2
_StrfStoreArg x3
_StrfStoreArg x4
_StrfStoreArg x5
_StrfStoreArg x6
_StrfStoreArg x7
jsr strf
.out .sprintf("info: Strf: called with %d arguments", @N_ARGS)
.endmacro
; TODO allocate zp memory
fmt_idx = $30
out_idx = $31
;********************************************************************************
; @function Format a string
; @details
; If there is no value to be read, the Pz will be set
; Formats:
; - x: unsigned hex integer (1 byte) -> 2 chars
; - X: unsigned hex integer (2 byte) -> 4 chars TODO
; - u: unsigned decimal integer (1 byte) TODO
; - U: unsigned decimal integer (2 bytes) TODO
; @param ARG0-1: Format string address
; @param ARG2-3: Output string address
; @param ARG4+: Additional parameters
; @returns
; @modifies: A, X, Y
;********************************************************************************
.proc strf
stz out_idx
stz fmt_idx
ldy #0 ; position in string
ldx #0 ; index of format args
@loop:
ldy fmt_idx
lda (ARG0),y
beq @null
cmp #'%'
beq @percent
@normal_char: ; store A in output string
ldy out_idx
sta (ARG2),y
inc fmt_idx
inc out_idx
beq @out_overflow
bra @loop
@percent: ; check for format in next position
iny
sty fmt_idx
lda (ARG0),y
beq @null
; formats
cmp #'x'
beq @format_hex1
bra @normal_char
@format_hex1: ; 1 byte hex -> 2 chars
lda ARG4,x
phx
jsr int8_to_hex_str
ldy out_idx
sta (ARG2),y ; most sig digit
iny
beq @out_overflow
txa
sta (ARG2),y ; least sig digit
iny
beq @out_overflow
sty out_idx
plx
inx ; 1 byte of args handeled
; bra @format_return
@format_return: ; increment fmt_idx to swallow the formating char
inc fmt_idx
bra @loop
@out_overflow: ; store 0 in last position
ldy #$ff
sty out_idx
@store_null:
lda #0
@null: ; store and return
ldy out_idx
sta (ARG2),y
@rts:
rts
.endproc
;********************************************************************************
; @function Convert a 1 byte number into two hex characters
; @param A: Number to convert
; @returns A: Most significant digit
; @returns X: Least significant digit
; @modifies A,X,Y
;********************************************************************************
.proc int8_to_hex_str
pha
and #%00001111
tay
ldx HEX_CHARS_UPPER,y
pla
div A,16
and #%00001111
tay
lda HEX_CHARS_UPPER,y
rts
.endproc
.rodata
HEX_CHARS_UPPER: .byte "0123456789ABCDEF"
HEX_CHARS_LOWER: .byte "0123456789abcdef"
.export strf
.endscope
.endif ; guard