`cli` module

Declare your CLI shape (flags, options, positionals), then parse argv into a map. Auto-generates a --help-style usage string.

import "cli" as cli;

var p = cli.parser("greet");
p.description = "Print a greeting.";
cli.flag      (p, {name: "shout",  short: "s", help: "Use upper case"});
cli.option    (p, {name: "lang",   short: "l", help: "en or bn", default: "en"});
cli.positional(p, {name: "name",                help: "Who to greet"});

var args = cli.parse(p);
print(args.lang, args.name, args.shout);

API

Function	Description
`cli.parser(name)` → parser	Start a new parser. Set `parser.description` for the help blurb.
`cli.flag(p, spec)`	Add a boolean flag. `spec`: `{name, short?, help?}`.
`cli.option(p, spec)`	Add an option that takes a value. `spec`: `{name, short?, help?, default?}`.
`cli.positional(p, spec)`	Add a positional arg. `spec`: `{name, help?, default?}`.
`cli.parse(p)` → map	Read real `sys.arg(*)` and produce the args map.
`cli.parse_argv(p, argv)` → map	Same, but parses a synthetic list (useful in tests).
`cli.usage(p)` → string	Build a `--help`-style usage string.

Output shape

The returned map has one entry per declared name:

Flags: bool (default false).
Options: string (default per spec).
Positionals: string (default per spec).
_rest — extra positionals past the declared ones.

See also

sys — the low-level sys.argc() / sys.arg(i) accessors cli sits on top of.