Re: Add a predicate for canonical file name

[Stefan Monnier]

> Using string= here will cause false negatives, e.g. with Windows file
> names that use backslashes vs forward slashes, or due to letter-case
> differences on case-insensitive file systems.  Did you really mean
> that?

Indeed, such notions have already been requested and discussed here, and
it's not clear exactly what is needed and when.

I can see several different meanings of "canonical", i.e. representative
member of an equivalence class (and I'd be inclined to prefer a function
that checks for "equivalence" between two file names rather than
a function that tries to find one canonical name).  The equivalence
classes could be:

- equivalent regardless of the actual on-disk data.  I.e. this can't
  take symlinks or hard links into account.  Questions remain about
  whether it could presume the "normal semantics of the most common
  file-system".  E.g. should it assume case-insensitive names in
  MacOS/Windows and case-sensitive in GNU/Linux?

- equivalent in practice for the current state of the file-system.
  You can test this equivalence by comparing the output of
  `file-attributes', except when the name corresponds to a file that
  doesn't exist (yet?).

Which flavor do you want?


        Stefan