cli

Command-line argument parsing for Ecko: typed flags, options, positionals, defaults, and generated usage. Pure - no capabilities.

ecko get github.com/ecko-lang/cli

import cli

Pure computation: it declares no capabilities, so it cannot touch the network, the filesystem or the environment.

Version 0.9.5 - source - MIT.

parser(name, description = "")

Start a command-line spec. Build it up with flag, opt and arg, then hand it to parse.

spec = parser("greet", "say hello")

flag(spec, name, help = "")

Add a boolean flag: present on the command line means true.

spec = flag(spec, "verbose", "print more")

opt(spec, name, opts = empty_map())

Add a named option that takes a value (--name value). opts may carry help, default, and required.

arg(spec, name, opts = empty_map())

Add a positional argument, in declaration order. opts may carry help, default, and required.

parse(spec, argv)

Parse argv against a spec, returning a map of flags, options and positional arguments. Raises with a usage message on unknown or missing arguments.

usage(spec)

The rendered --help text for a spec: description, usage line, then the flags, options and positional arguments with their help strings.