Re: Off Topic (was: bug#31544)

[Yuri Khan]

On Thu, May 24, 2018 at 11:38 PM Alan Mackenzie <address@hidden> wrote:

> rx.el uses a wordy syntax, somewhat analagously to Cobol 50 years ago.
> Its premiss is that it's the terse, dense, austere characters which make
> a regexp difficult to write and read.  I would suggest that it's more
> the abstract concepts which cause beginners difficulties, rather than
> the syntax.  This was true of Cobol 50 years ago, and I think it's
> always been the case with regexps.

> That said, rx.el is used ~72 times in 19 files.el in Emacs, so somebody
> likes it.

I like rx.el.

I like it because any reasonably involved rx.el expression will be written
out on multiple lines, indented, and possibly commented; whereas the
equivalent plain regexp will be jumbled up on one long line, or else broken
up into a concat of several arbitrary parts.

I like rx.el because its expressions can be navigated structurally, using
‘backward-up-list’, ‘forward-sexp’, and the like. The same commands work on
regular regular expressions only if they have not been broken up for
readability.

I also like rx.el because it allows me to see fewer backslashes,
double-backslashes, and quadruple-backslashes.