use "alloc"use "die"use "extremum"use "slcp"use "types"use "utf"use "memops" pkg std =	type strbuf = struct		buf	: byte[:]		len	: size		fixed	: bool	;; 	const mksb	: (-> strbuf#)	const mkbufsb	: (buf : byte[:] -> strbuf#)	const sbfin	: (sb : strbuf# -> byte[:])	const sbfree	: (sb : strbuf# -> void)	const sbpeek	: (sb : strbuf# -> byte[:]) 	const sbputc	: (sb : strbuf#, v : char -> bool)	const sbputs	: (sb : strbuf#, v : byte[:] -> bool)	const sbputb	: (sb : strbuf#, v : byte -> bool)	const sbtrim	: (sb : strbuf#, len : size -> void);; const mksb = {	var sb	sb = zalloc()	sb.buf = slalloc(1)	-> sb} const mkbufsb = {buf	var sb 	sb = zalloc()	sb.buf = buf	sb.fixed = true	-> sb} const sbfin = {sb	var sl 	sl = sb.buf[:sb.len]	free(sb)	-> sl} const sbfree = {sb	if !sb.fixed		slfree(sb.buf)	;;	free(sb)}  const sbpeek = {sb : strbuf#	-> sb.buf[:sb.len]} const sbputc = {sb, v	if !ensure(sb, charlen(v))		-> false	;;	sb.len += encode(sb.buf[sb.len:], v)	-> true}const sbputs = {sb, v	var ok	var len 	ok = ensure(sb, v.len)	/* copy what we can */	len = min(sb.buf.len - sb.len, v.len)	slcp(sb.buf[sb.len:sb.len + len], v[:len])	sb.len += len	-> ok}const sbputb = {sb, v	if !ensure(sb, 1)		-> false	;;	sb.buf[sb.len++] = v	-> true} const sbtrim = {sb, len	len = min(sb.len, len)	if len < 0		sb.len -= abs(len)	else		sb.len = len	;;} const ensure = {sb, len	if sb.fixed && sb.len + len > sb.buf.len		-> false	;;	while sb.buf.len < sb.len + len		slgrow(&sb.buf, 2*sb.buf.len)	;;	-> true}