henesy / args-myr

Command line flag parsing library for Myrddin

Libargs — Myrddin

Commandline argument (flag) parsing library for the Myrddin programming language.

Styled after the Inferno arg.m as per http://man.cat-v.org/inferno/2/arg.

The Myrddin programming language: https://myrlang.org

Build

mbld

Test

mbld test

Install

mbld install

Demo

mbld
./obj/argsdemo

Usage

The args.init() function must be called before any others.

The args.argv() function may be called safely at any time, but is intended to be called after all flags have been parsed.

API reference:

pkg args =
	// Must be called first ­ initializes the library
	const init     : (args : byte[:][:] → void)

	// Sets the library usage string
	const setusage : (str : byte[:] → void)

	// Emits and exits for usage
	const usage    : (→ void)

	// Emits the next flag character in the flag chain
	const opt      : (→ char)

	// Returns the current argument which must not be nil
	const earg     : (→ byte[:])

	// Returns the argv0 of the input, our program name
	const progname : (→ byte[:])

	// Print remaining arguments
	const argv     : (→ byte[:][:])
;;

Example

A more complete example exists in demo.myr.

Generic usage of libargs:

const main = {argv : byte[:][:]

	args.init(argv)

	args.setusage("test [-h] [-n N] name…")

	var c
	while((c = args.opt()) != (0 : char))
		match c
		| 'h':
			std.put("help!\n")
		| 'n':
			std.put("N = {}\n", args.earg())
		| _:
			args.usage()
		;;
	;;

	// Print remaining arguments
	for a : args.argv()
		std.put("→ {}\n", a)
	;;

	…
}