( ulz decoder )

|10 @Console &vector $2 &read $1 &pad $4 &type $1 &write $1 &error $1
|a0 @File &vector $2 &success $2 &stat $2 &delete $1 &append $1 &name $2 &length $2 &read $2 &write $2

|0000

	@src $30
	@dst $30
	@ptr $1

|0100

@on-reset ( -> )
	;meta #06 DEO2
	.Console/type DEI #03 AND ?{
		;dict/usage <perr>/
		#010f DEO }
	;&await .Console/vector DEO2
	BRK
	&await ( -> )
		.Console/read DEI .src skey ?ready-dst
		BRK

@ready-dst ( -> )
	;&await .Console/vector DEO2
	BRK
	&await ( -> )
		.Console/read DEI .dst skey ?on-ready
		BRK

@meta $1
	( name ) "Ulzdec 0a
	( desc ) "ULZ 20 "Decoder 0a
	( auth ) "By 20 "Devine 20 "Lu 20 "Linvega 0a
	( date ) "19 20 "Nov 20 "2023 $1
	( exts ) 00

@on-ready ( -> )
	;src <decode_ulz>
	( | export )
	;dst .File/name DEO2
	.ptr LDZ2 ;mem SUB2 .File/length DEO2
	;mem .File/write DEO2
	( | summary )
	;dict/decompressed <pstr>
	;src <pstr>
	;dict/spacer <pstr>
	;dst <pstr>
	[ LIT2 "( 18 ] DEO
	.ptr LDZ2 ;mem SUB2 <pdec>
	;dict/bytes <pstr>
	[ LIT2 ") 18 ] DEO
	#0a18 DEO
	( halt ) #800f DEO
	BRK

@<decode_ulz> ( str* -- )
	;mem .ptr STZ2
	.File/name DEO2
	&stream ( -- )
		#0001 .File/length DEO2
		;&b DUP2 .File/read DEO2
		.File/success DEI2 ORA ?{ POP2 JMP2r }
		[ LIT &b $1 ] <decode_ulz_byte>
		!&stream

@<decode_ulz_byte> ( byte -- )
	DUP #80 AND ?op-cpy

@op-lit ( byte -- )
	#00 SWP INC2 DUP2 .File/length DEO2
	.ptr LDZ2 DUP2 .File/read DEO2
	ADD2 .ptr STZ2
	JMP2r

@op-cpy ( byte -- )
	#7f AND DUP #40 AND ?{ #00 SWP !&copy }
	#3f AND getc
	&copy ( length* -- )
		.ptr LDZ2 #00 getc INC2 SUB2 ,&offset STR2
		#0004 ADD2 #0000
	&l ( length* i* -- )
		( get ) DUP2 [ LIT2 &offset $2 ] ADD2 LDA
		( put ) .ptr LDZ2 STAk INC2 .ptr STZ2
		POP INC2 GTH2k ?&l
	POP2 POP2 JMP2r

(
@|stdlib )

@skey ( key buf -- proc )
	OVR #21 LTH ?&eval
	#00 SWP sput #00 JMP2r
	&eval POP2 #01 JMP2r

@scap ( str* -- end* )
	&w INC2 & LDAk ?&w
	JMP2r

@sput ( chr str* -- )
	scap/ INC2k #00 ROT ROT STA
	STA
	JMP2r

@getc ( -- b )
	#0001 .File/length DEO2
	;&b .File/read DEO2
	[ LIT &b $1 ] JMP2r

@<pstr> ( str* -- )
	&w LDAk #18 DEO
	INC2 & LDAk ?&w
	POP2 JMP2r

@<perr> ( str* -- )
	&w LDAk #19 DEO
	INC2 & LDAk ?&w
	POP2 JMP2r

@<pdec> ( short* -- )
	#2710 [ LIT2r 00fb ]
	&w ( -- )
		DIV2k #000a DIV2k MUL2 SUB2 SWPr EQUk OVR STHkr EQU AND ?{
			DUP [ LIT "0 ] ADD #19 DEO
			INCr }
		POP2 #000a DIV2 SWPr INCr STHkr ?&w
	POP2r POP2 POP2 JMP2r

(
@| mem )

@dict &usage "usage: 20 "ulzdec.rom 20 "a.bin 20 "b.ulz 0a $1
	&decompressed "Decompressed 20 $1
	&spacer 20 "-> 20 $1
	&bytes 20 "bytes $1

@mem