Std.Args.parse

fn

This is a callable function.

What it does

Read arguments against a spec, in one pass.

The forms accepted are the ones people write: `--name value`, `--name=value`,

`-n value`, `-nvalue`, and `-abc` for three flags at once. A bare `--` ends

the options, so a value that looks like one — a file called `-`, a pattern

beginning with a dash — can still be given.

Read the signature

• The text after the name is the type checked by Pudu.
• Read arrows from left to right: inputs come first, and the final type is returned.
• & borrows a value for this call instead of moving or copying it.
• Names inside [ ] are type arguments, such as the item type held by a collection.
• Result makes success and recoverable failure part of the function's type.