Are those globs or regexes?
Can you include the full function signature in the issue body, as well as examples of what would match?

This arises from some discussion on https://go.dev/cl/418556.

I think the signature would be:

// TypeByPath returns the MIME type associated with a filename.
// If the name has no associated type, TypeByPath returns "".
func TypeByPath(path string) string

The motivation is that not every pattern in the MIME-info database can be expressed as an extension. In particular, these four entries are a problem:

60:application/x-sharedlib:*.so.[0-9]*
50:video/x-anim:*.anim[1-9j]
50:application/x-troff-man:*.[1-9]
50:video/mpeg:[0-9][0-9][0-9].vdr

The video/x-anim and application/x-troff-man entries could be expanded into a reasonable number of extensions (.anim1, .anim2, etc.), but video/mpeg has 1000 possible suffixes (none of which start with a .) and application/x-sharedlib isn't a suffix at all.

Thank you for clarifying it and sorry I did not describe it well!

Change https://go.dev/cl/418556 mentions this issue: mime: range glob expansions in type_unix.go