RFC: Regex support?

[darrenldl]

After speaking with author of Stitch, I am planning to add a result narrowing functionality, where you can specify multiple filters to shrink the set of files considered.

As part of this work, a non-fuzzy way of specifying search needs to be added, of which I am considering regex. There was a similar functionality in Docfd called content requirement expression, but was removed from 3.0.0 as it felt awkward to use in practice, being a limited version of the search expression.

So the question is whether regex should be added, and if so, should both line based (i.e. regular grep) and token based regex (e.g. ?ello w*d can match hello and world separated by other tokens or lines as long as it is under the limit used by the regular mode) be added?

(Tagging people who I think are likely to be regular users: @kseistrup @ludwig-austermann)

[darrenldl]

Opted to using fzf search syntax.