ref: f4a4987fb85dc9ea146146068734988bb046a3ab
dir: /lib/std/fmt.myr/
use "alloc.use"
use "chartype.use"
use "die.use"
use "extremum.use"
use "fltfmt.use"
use "hashfuncs.use"
use "hasprefix.use"
use "htab.use"
use "introspect.use"
use "intparse.use"
use "option.use"
use "sleq.use"
use "slpush.use"
use "strbuf.use"
use "strfind.use"
use "strsplit.use"
use "syswrap-ss.use"
use "syswrap.use"
use "types.use"
use "utf.use"
use "varargs.use"
pkg std =
	/* write to fd */
	const put	: (fmt : byte[:], args : ... -> size)
	const fput	: (fd : fd, fmt : byte[:], args : ... -> size)
	const putv	: (fmt : byte[:], ap : valist# -> size)
	const fputv	: (fd : fd, fmt : byte[:], ap : valist# -> size)
	/* write to buffer */
	const fmt	: (fmt : byte[:], args : ... -> byte[:])
	const fmtv	: (fmt : byte[:], ap : valist# -> byte[:])
	const bfmt	: (buf : byte[:], fmt : byte[:], args : ... -> byte[:])
	const bfmtv	: (buf : byte[:], fmt : byte[:], ap : valist# -> byte[:])
	/* write to strbuf */
	const sbfmt	: (buf : strbuf#, fmt : byte[:], args : ... -> size)
	const sbfmtv	: (buf : strbuf#, fmt : byte[:], ap : valist# -> size)
	/* add a formatter function */
	const fmtinstall	: (ty : byte[:], \
		fn : (sb : strbuf#, ap : valist#, opts : (byte[:],byte[:])[:] -> void), \
		optdesc : (byte[:], bool)[:] \
		-> void)
	$noret const fatal	: (fmt : byte[:], args : ... -> void)
	$noret const fatalv	: (fmt : byte[:], ap : valist# -> void)
;;
const __init__ = {
	fmtmap = mkht(strhash, streq)
}
type fmtdesc = struct
	fn	: (sb : strbuf#, ap : valist#, opts : (byte[:],byte[:])[:] -> void)
	optdesc	: (byte[:], bool)[:]
;;
/* same as 'put', but exits the program after printing */
const fatal = {fmt, args
	var ap
	ap = vastart(&args)
	putv(fmt, &ap)
	exit(1)
}
/* same as 'putv', but exits the program after printing */
const fatalv = {fmt, ap
	putv(fmt, ap)
	exit(1)
}
var fmtmap : htab(byte[:], fmtdesc)#
const fmtinstall = {ty, fn, optdesc
	htput(fmtmap, ty, [.fn=fn, .optdesc=optdesc])
}
const put = {fmt, args
	var ap
	ap = vastart(&args)
	-> fputv(1, fmt, &ap)
}
const putv = {fmt, ap
	-> fputv(1, fmt, ap)
}
const fput = {fd, fmt, args
	var ap
	ap = vastart(&args)
	-> fputv(fd, fmt, &ap)
}
const fputv = {fd, fmt, ap
	var sb, s
	sb = mksb()
	sbfmtv(sb, fmt, ap)
	s = sbfin(sb)
	-> writeall(fd, s)
}
const fmt = {fmt, args
	var ap
	ap = vastart(&args)
	-> fmtv(fmt, &ap)
}
const fmtv = {fmt, ap
	var sb
	sb = mksb()
	sbfmtv(sb, fmt, ap)
	-> sbfin(sb)
}
const bfmt = {buf, fmt, args
	var ap
	ap = vastart(&args)
	-> bfmtv(buf, fmt, &ap)
}
const bfmtv = {buf, fmt, ap
	var sb
	sb = mkbufsb(buf)
	sbfmtv(sb, fmt, ap)
	-> sbfin(sb)
}
const sbfmt = {sb, fmt, args
	var ap
	ap = vastart(&args)
	-> sbfmtv(sb, fmt, &ap)
}
const sbfmtv = {sb, fmt, ap -> size
	var nfmt, nparams, orig
	var c, params
	orig = fmt
	nparams = ap.tc.nelt
	nfmt = 0
	while fmt.len != 0
		(c, fmt) = striter(fmt)
		match c
		| '{':
			if decode(fmt) == '{'
				(c, fmt) = striter(fmt)
				sbputc(sb, '{')
			else
				(params, fmt) = getparams(fmt)
				nfmt++
				if nfmt > nparams
					die("too few params for fmt\n")
				;;
				fmtval(sb, vatype(ap), ap, params)
			;;
		| '}':
			if decode(fmt) == '}'
				sbputc(sb, '}')
			;;
		| chr:
			sbputc(sb, chr)
		;;
:fmtdone
	;;
	if nfmt != nparams
		write(1, orig)
		die("too many params for fmt\n")
	;;
	-> sb.len
}
const fmtval = {sb, ty, ap, params
	var pl
	match htget(fmtmap, ty)
	| `Some f:
		pl = parseparams(params, f.optdesc)
		f.fn(sb, ap, pl)
		std.slfree(pl)
	| `None:
		fallbackfmt(sb, params, ty, ap)
	;;
}
const parseparams = {paramstr, optdesc
	var params, opts
	var o, a, ha : bool, gotarg : bool
	opts = [][:]
	if optdesc.len == 0 && paramstr.len > 0
		std.fatal("invalid format options {}\n")
	;;
	params = strsplit(paramstr, ",")
	for p in params
		/* parse out the key/value pair */
		match std.strfind(p, "=")
		| `std.Some idx:
			o = p[:idx]
			a = p[idx+1:]
			gotarg = true
		| `std.None:
			o = p
			a = ""
			gotarg = false
		;;
		/* verify and add the arg */
		for (opt, hasarg) in optdesc
			if !std.sleq(opt, o)
				continue
			;;
			ha = hasarg
			if ha == gotarg
				opts = std.slpush(opts, (o, a))
			else
				std.fatal("invalid option {}", o)
			;;
		;;
	;;
	slfree(params)
	-> opts
}
const fallbackfmt = {sb, params, tyenc, ap : valist# -> void
	/* value types */
	var t_val : bool
	var b_val : int8, ub_val : uint8
	var w_val : int16, uw_val : uint16
	var i_val : int32, ui_val : uint32
	var l_val : int64, ul_val : uint64
	var z_val : size
	var p_val : byte#
        var c_val : char
	var s_val : byte[:]
	var f32_val : flt32, f64_val : flt64
	var i8 : int8, i16: int16, i32 : int32
	var by : byte
	var i : int, i64 : int64
	var ui8 : int8, ui16: int16, ui32 : int32
	var ui : int, ui64 : int64
	var subap, subenc, subname
	match typedesc(tyenc)
	| `Tynone:	/* nothing */
	/* atomic types */
	| `Tyvoid:
		sbputs(sb, "void")
	| `Tybool:
		t_val = vanext(ap)
		if t_val
			sbputs(sb ,"true")
		else
			sbputs(sb, "false")
		;;
	| `Tychar:
		c_val = vanext(ap)
		sbputc(sb, c_val)
	| `Tyint8:
		b_val = vanext(ap)
		intfmt(sb, intparams(params), true, b_val)
	| `Tyint16:
		w_val = vanext(ap)
		intfmt(sb, intparams(params), true, w_val)
	| `Tyint:
		i_val = vanext(ap)
		intfmt(sb, intparams(params), true, i_val)
	| `Tyint32:
		i_val = vanext(ap)
		intfmt(sb, intparams(params), true, i_val)
	| `Tyint64:
		l_val = vanext(ap)
		intfmt(sb, intparams(params), true, l_val)
	| `Tybyte:
		ub_val = vanext(ap)
		intfmt(sb, intparams(params), false, ub_val)
	| `Tyuint8:
		ub_val = vanext(ap)
		intfmt(sb, intparams(params), false, ub_val)
	| `Tyuint16:
		uw_val = vanext(ap)
		intfmt(sb, intparams(params), false, uw_val)
	| `Tyuint:
		ui_val = vanext(ap)
		intfmt(sb, intparams(params), false, ui_val)
	| `Tyuint32:
		ui_val = vanext(ap)
		intfmt(sb, intparams(params), false, ui_val)
	| `Tyuint64:
		ul_val = vanext(ap)
		intfmt(sb, intparams(params), false, ul_val)
	| `Tyflt32:
		f32_val = vanext(ap)
		flt32bfmt(sb, f32_val, MNormal, 0)
	| `Tyflt64:
		f64_val = vanext(ap)
		flt64bfmt(sb, f64_val, MNormal, 0)
	| `Tyvalist:
		sbputs(sb, "...")
	/* compound types */
	| `Typtr desc:
		p_val = vanext(ap)
		sbputs(sb, "0x")
		intfmt(sb, \
			[.base=16, .padto=2*sizeof(void#), .padfill='0'], \
			false, p_val castto(intptr))
	| `Tyslice desc:
		match typedesc(desc)
		| `Tybyte:
			s_val = vanext(ap)
			strfmt(sb, s_val, params)
		| _:
			subap = vaenter(ap)
			sbputs(sb, "[")
			while subap.tc.nelt != 0
				fmtval(sb, vatype(&subap), &subap, "")
				if subap.tc.nelt > 0
					sbfmt(sb, ", ")
				;;
			;;
			sbputs(sb, "]")
			vabytes(ap)
		;;
	| `Tyfunc tc:
		p_val = vanext(ap)
		sbputs(sb, "func{")
		intfmt(sb, \
			[.base=16, .padto=2*sizeof(void#), .padfill='0'], \
			false, p_val castto(intptr))
		sbputs(sb, "}")
		vabytes(ap)
	| `Tyarray (sz, desc):
		subap = vaenter(ap)
		sbputs(sb, "[")
		while subap.tc.nelt != 0
			fmtval(sb, vatype(&subap), &subap, "")
			if subap.tc.nelt > 0
				sbfmt(sb, ", ")
			;;
		;;
		sbputs(sb, "]")
		vabytes(ap)
	/* aggregate types */
	| `Tytuple tc:
		subap = vaenter(ap)
		sbfmt(sb, "(")
		for var i = 0; i < subap.tc.nelt; i++
			fmtval(sb, vatype(&subap), &subap, "")
			if subap.tc.nelt == 1
				sbfmt(sb, ",")
			elif i != subap.tc.nelt -1 
				sbfmt(sb, ", ")
			;;
		;;
		sbfmt(sb, ")")
		vabytes(ap)
	| `Tystruct nc:
		subap = vaenter(ap)
		sbfmt(sb, "[")
		for var i = 0; i < subap.tc.nelt; i++
			(subname, subenc) = ncpeek(&subap.tc)
			sbfmt(sb, ".{}=", subname)
			fmtval(sb, vatype(&subap), &subap, "")
			if subap.tc.nelt == 1
				sbfmt(sb, ",")
			elif i != subap.tc.nelt -1 
				sbfmt(sb, ", ")
			;;
		;;
		sbfmt(sb, "]")
		vabytes(ap)
	| `Tyunion nc:
		subap = vaenter(ap)
		i_val = (ap.args castto(int32#))#
		for var i = 0; i < i_val; i++
			ncnext(&nc)
		;;
		(subname, subenc) = ncnext(&nc)
		sbfmt(sb, "`{} ", subname)
		fmtval(sb, subenc, &subap, "")
		vabytes(ap)
	| `Tyname (name, desc):
		subap = vaenter(ap)
		fallbackfmt(sb, params, desc, &subap)
		vabytes(ap)
	;;
}
const getparams = {fmt
	var i
	for i = 0; i < fmt.len; i++
		if fmt[i] == '}' castto(byte)
			goto foundparams
		;;
	;;
	die("invalid format string")
:foundparams
	-> (fmt[:i], fmt[i+1:])
}
type intparams = struct
	base	: size
	padto	: size
	padfill	: char
;;
const intparams = {params
	var ip : intparams
	var opts
	ip = [
		.base = 10,
		.padfill = ' ',
		.padto = 0
	]
	opts = parseparams(params, [
		("x", false),
		("w", true),
		("p", true)][:])
	for o in opts
		match o
		| ("x", ""):	ip.base = 16
		| ("w", wid):	ip.padto = getint(wid, "fmt: width must be integer")
		| ("p", pad):	ip.padfill = decode(pad)
		| _:	std.die("unreachable")
		;;
	;;
	std.assert(ip.padto >= 0, "pad must be >= 0")
	std.slfree(opts)
	-> ip
}
const strfmt = {sb, str, params
	var opts
	var w, p, i
	p = ' '
	w = 0
	opts = parseparams(params, [
		("w", true),
		("p", true)][:])
	for o in opts
		match o
		| ("w", wid):	w = getint(wid, "fmt: width must be integer")
		| ("p", pad):	p = decode(pad)
		| _:	std.die("unreachable")
		;;
	;;
	std.assert(p >= 0, "pad must be >= 0")
	std.slfree(opts)
	for i = 0; i < w - graphemewidth(str); i++
		sbputc(sb, p)
	;;
	sbputs(sb, str)
}
/*
Hah. like we're going to put in the work to actually
count graphemes.
*/
const graphemewidth = {str
	-> str.len
}
const digitchars = [
	'0','1','2','3','4',
	'5','6','7','8','9',
	'a','b','c','d','e','f'
]
generic intfmt = {sb, opts, signed, bits : @a::(integral,numeric)
	var isneg
	var val
	var b : char[32]
	var i, j, npad
	var base
	base = opts.base castto(uint64)
	if signed && bits < 0
		val = -bits castto(uint64)
		isneg = true
	else
		val = bits castto(uint64)
		val &= ~0 >> (8*(sizeof(uint64)-sizeof(@a)))
		isneg = false
	;;
	i = 0
	if val == 0
		b[0] = '0'
		i++
	;;
	while val != 0
		b[i] = digitchars[val % base]
		val /= base
		i++
	;;
	npad = clamp(opts.padto - i, 0, opts.padto)
	if isneg
		npad--
	;;
	if opts.padfill == '0' && isneg
		sbputc(sb, '-')
	;;
	for j = 0; j < npad; j++
		sbputc(sb, opts.padfill)
	;;
	if opts.padfill != '0' && isneg
		sbputc(sb, '-')
	;;
	for j = i; j != 0; j--
		sbputc(sb, b[j - 1])
	;;
}
const writeall = {fd, buf
	var n, len
	len = 0
	while true
		n = write(fd, buf)
		if n <= 0 || n >= len
			break
		;;
		len += n
	;;
	-> len
}
/* would use std.get(), but that's a dependency loop */
const getint = {s, msg
	match std.intparse(s)
	| `Some w:	-> w;
	| `None:	die(msg)
	;;
}