From: Gavin Sinclair <gsinclair@...>
Date: 2002-08-06T00:13:22+09:00
Subject: Re: Regex question


----- Original Message -----
From: "Mike Hall" <mghall@enteract.com>

[All sorts of people wrote all sorts of things, and then...]

> >
> >    /[^.]*$/.match(file)[0]
>
> Now wouldn't all this be much simpler if we had a method
> along the lines of 'basename', which would pull off the
> extension (or suffix) for us?  We already have File::basename
> and File::dirname, so why not a File::last-part-of-the-name-name?
>
> Or what about a 'File::parts' which returns an array of:
> directory (or nil), root name (or nil), suffix(es) (or nil).
> Would that be more Ruby-esqe?
>

I agree there's room for some help from the File module here.  We already
have

  File.split("/home/fred/aliases.sh")  # -> ["/home/fred", "aliases.sh"]

which is nice.  I think the most sensible think is for this method to take
an optional parameter, indicating whether the extension should be a separate
element.  In fact, it could be an integer specifying how many dots to
include in the extension.  So:

  File.split("tuesday.txt")               # -> [".", "tuesday.txt"]
  File.split("/games/doom.tar.gz")        # -> ["/games", "doom.tar.gz"]
  File.split("/games/doom.tar.gz", 1)     # -> ["/games", "doom.tar", "gz"]
  File.split("/games/doom.tar.gz", 2)     # -> ["/games", "doom", "tar.gz"]
  File.split("/games/doom.tar.gz", 3)     # -> ["/games", "doom", "tar.gz"]

Note that the first two lines represent current File.split behaviour, and
the final three are proposed extensions.  The method "split" is very
appropriate here, as (and I should have thought of this earlier)
String.split can be used to chop up a filename into extensions in this
manner.

Of course, we'd need File.extension(path, n=1) to match File.dirname and
File.basename, as well.

--Gavin