Basic default rules?

[khionu]

I think it might be a nice addition, maybe as a Crate Feature, to have some basic defaults, such as for matching alphanumerics, newlines, etc. use peg::preset_rules; at the top of a grammar, and have access to a set of "primitives", so to speak.

[khionu]

Can this get a "Help wanted" or "Good first issue" label, to bring some contributor attention to this?

[kevinmehall]

This is blocked on an imports mechanism (#25) or some other way to inject the library into your grammar, which requires some design and deeper implementation work.

However, we could start collecting these basic rules into a file under tests/run-pass/, which in the mean time would be a handy reference.