args.myr

use std

var reverse

const main = {args : byte[:][:]
	var cmd
	var mark = "→ "
	var delay = 200 * std.Msec
	reverse = false

	cmd = std.optparse(args, &[
		.argdesc = "words…",
		.opts = [
			[.opt='r',						.desc = "reverse output"],
			[.opt='m',	.arg = "mark",		.desc = "list items with prefix 'mark'"],
			[.opt='T',	.arg = "period",	.desc = "set print sleep delay to 'period' ms"],
		][:]
	])

	for opt : cmd.opts
		match opt
		| ('r', ""):
			reverse = true
		| ('m', arg):
			mark = arg
		| ('T', arg):
			match std.intparse(arg)
			| `std.Some v:
				delay = v * std.Msec
			| `std.None:
				std.fatal("err: invalid argument for period\n")
			;;
		| _:
			std.fatal("unreachable\n")
		;;
	;;

	if reverse
		var i
		for i = 0; i < cmd.args.len / 2; i++
			var tmp
			tmp = cmd.args[i]
			cmd.args[i] = cmd.args[cmd.args.len - 1 - i]
			cmd.args[cmd.args.len - 1 - i] = tmp
		;;
	;;

	for arg : cmd.args
		std.put("{} {}\n", mark, arg)
		std.usleep(delay)
	;;
}