Feature: discard operator for terminals?

Played around with this on friday, and the biggest distraction while trying to develop a grammar, was whitespace and comment nodes, which generate a lot of noise.

It’s pretty common to need to allow optional whitespace (and/or comments) in or around various statements and blocks, and I suppose there could be other types of terminals (commas or other separators, string delimiters, etc.) which could be usefully discarded.

How about adding a discard operator?

Maybe something like a prefix operator @ to “mute” an expression - here’s a small portion of JSON grammar with whitespace and commas muted:

grammar CanopyJson

document  <-  @__ (object / array) @__

object    <-  "{" pair (@"," pair)* "}" / "{" @__ "}"

...

__        <-  [\s]*

Would that work?

[y8]

Could you please make a release with this feature? This is really hard do deal with whitespace/comments nodes

[guioconnor]

Hello.

I believe this never made it to production; npm’s latest release date is 3y ago and a quick try breaks the compilation on the @ symbol. Is there any plan to release this feature?