Also sed supports any character separator ie:

    $ echo http://foobar.com/mai/path/meme.png | sed 's@/mai/path@/sweet/new/path@'
    http://foobar.com/sweet/new/path/meme.png

Consider any separator

If you only support substitutions (the "s" command) maybe @sedy <separator><regexp><separator><replacement><separator><flags> that way you could e.g.

    @sedy |foo/bar|foo|g

?