use "alloc"use "assert"use "die"use "extremum"use "mk"use "now"use "putint"use "types" pkg std =	type rng 	const mksrng	: (seed : uint32 -> rng#)	const freerng	: (rng : rng# -> void) 	generic rand	: (lo : @a, hi : @a -> @a) :: numeric,integral @a	generic randnum	: (-> @a) :: numeric,integral @a	const randbytes	: (buf : byte[:] -> void) 	generic rngrand	: (rng : rng#, lo : @a, hi : @a -> @a) ::numeric,integral @a	generic rngrandnum	: (rng : rng# -> @a) :: numeric,integral @a	const rngrandbytes	: (rng : rng#, buf : byte[:] -> void);; type rng = struct	s0 : uint64	s1 : uint64;; var _rng generic rand	= {lo, hi;	-> rngrand(&_rng, lo, hi)}generic randnum	= {;	-> rngrandnum(&_rng)}const randbytes	= {buf;	-> rngrandbytes(&_rng, buf)} const __init__ = {	_rng.s0 = (now() : uint64)	_rng.s1 = (now() : uint64)} const mksrng = {seed : uint32 -> rng#	-> std.mk([		.s0=(seed & 0xffff : uint64),		.s1=(seed&0xffff0000>>16 : uint64)	])} const freerng	= {r	std.free(r)} generic rngrand = {rng, lo, hi	var span, lim, val, max		span = abs(hi - lo)	max = ~0	/* if ~0 is negative, we have a signed value with a different max */	if max < 0	        max = (1 << (8*sizeof(@a)-1)) - 1	;;		lim = (max/span)*span	val = (rngrandnum(rng) & max)	while val > lim	        val = (rngrandnum(rng) & max)	;;	-> val % span + lo} const rngrandbytes = {rng, buf	var n, r : uint64 	n = 0	for var i = 0; i + 8 < buf.len/8; i++		r = rngrandnum(rng)		putle64(buf[n:n+8], r)		n += 8	;;	r = rngrandnum(rng)	for ; n != buf.len; n++		buf[n] = (r & 0xff : byte)		r >>= 8	;;}  /*Generate a number using the xoroshiro algorithm, asdesigned by David Blackman and Sebastiano Vigna. See http://xoroshiro.di.unimi.it/ for details.*/generic rngrandnum = {rng -> @a :: numeric,integral @a	var s0, s1, r 	s0 = rng.s0	s1 = rng.s1 	r = s0 + s1	s1 ^= s0 	rng.s0 = (s0 << 55 | s0 >> 9) ^ s1 ^ (s1 << 14)	rng.s1 = (s1 << 36 | s1 >> 28)	-> (r : @a)}