Support %, %%, #, ## expansion

[pombredanne]

It would be great if %, %%, #, ## expansions were supported
See https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html

[sayanarijit]

Looks interesting, but pattern matching requires working with regex, which has different implementations in different programs. Definitely needs some research and probably implementation complexity too. Not sure if there's any use case worth the effort. I'll keep this issue open though.

[pombredanne]

My use case is parsing m4, ebuild, PKGBUILD and APKBUILD files. Using the stdlib fnmatch is likely all you need and no re involved IMHO

[sayanarijit]

I think we still need to deal with regex. For example, let's consider the string abcabbcd, and we want to match a*c.
# substitution should give us abbcd, and ## substitution should give us d.
But I couldn't find a straightforward way to achieve this with fnmatch. Let me know if you have any ideas.

[sayanarijit]

Worst case we'll need to try matching every possible combinations explicitly. I hope there's a better way.