How to make a rule both silent and atomic?

[hillin]

I'd like a rule to be silent, but also atomic so it cannot have implicit whitespaces.
Some attempts:

// does not compile
foo_and_bar = _@{ foo ~ bar }

// does not compile
foo_and_bar = @_{ foo ~ bar }

// does not work, it hides `_foo_and_bar` but not `foo_and_bar`
foo_and_bar = @{ foo ~ bar }
_foo_and_bar = _{ foo_and_bar }

[Alextopher]

Being atomic means all the children rules are silent. If the atomic was also silent that would make the whole chain silent. Maybe a bit more details about exactly what you plan to use this for would help. You probably want the type above _foo_and_bar to be silent.

Such as:

foo_and_bar = @{ foo ~ bar }
_foo_and_bar = _{ foo_and_bar }
list = _{ SOI ~ _foo_and_bar* ~ EOI }

This gives you [ foo_and_bar [], foo_and_bar [], foo_and_bar [], ... ] as the final Pairs object

[hillin]

I have a certain pattern repeatedly appear in various places, so I'd like to abstract it out and made a rule (foo_and_bar). The thing is, I don't want to have foo_and_bar in the output tokens (only using it as an alias), so it'd better be silent. This all works great until I want to manually control the whitespaces in the pattern, which requires foo_and_bar to be atomic (or actually, composite atomic in my case).

[Alextopher]

Ah so you actually want the whole chain silent. I cannot seem to get any pattern to work expect putting foo_and_bar into the COMMENT or WHITESPACE block. Not sure if anything else can be done until there is an atomic silent specifier is created