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NNTP-Posting-Date: Sat, 15 Dec 2012 05:54:04 -0600
From: "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org>
Newsgroups: comp.lang.java.programmer
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Subject: Re: multi-line Strings
Date: Sat, 15 Dec 2012 11:54:15 -0000
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Xref: csiph.com comp.lang.java.programmer:20353

Arne Vajhøj wrote:

> The regex syntax itself is not exactly a good example of readability.

This, I think, is the point.  We don't need a special String syntax to fix the
problem with regexps -- we'd be much better off with a fixed regexp syntax.
Something OO.  And (since this is Java) I don't think that we need be afraid of
something verbose.

Off-the-top-of-my-head (all classes and method are imaginary):

    Regexp alpha = Regexp.fromList(java.lang.text.portable.Alphas);
    alpha = alpha.or('_');
    Regexp num = Regexp.fromList(java.lang.text.portable.Digits);
    Regexp alphanum = alpha.or(num);
    Regexp identifier = alpha.followedBy(alphanum.repeated());

Naturally, I'd prefer something a /bit/ less verbose, but Java won't support
that.  But even with the verbosity, I think my version is /far/ better.  It
puts the composition of regexps into the programmer's hands which means that it
can be approached like any other complex programming task.  Quoting/escaping
problems go away.  Grouping (bracketing) problems go away (and become
decoupled from the backreference concept.  Comments become trivially easy to
add.  Various kinds of abstraction and reuse are possible.

    -- chris

P.S. Mind you: my /real/ opinion is that regular expressions have no place in
production code except in the construction of scanners (for which a more
directly-applicable implementation than standalone regexps is helpful).
Regexps are for users to enter, or go into configuration data.  At least the
suggestion above has the advantage -- from my point of view -- that regexps no
longer look like "quick and easy" fixes to problems, and maybe the programmer
would think more about whether they /actually/ solve [all of] the problem at
hand.

P.P.S  UK post codes...