[GSOC] regular expressions beta is here

[Steven Schveighoffer]

On Wed, 10 Aug 2011 07:51:32 -0400, Dmitry Olshansky  
<dmitry.olsh at gmail.com> wrote:

> On 10.08.2011 15:34, Jacob Carlborg wrote:
>> On 2011-08-10 12:42, Dmitry Olshansky wrote:
>>> In case I failed to mention it before, I m working on the project
>>> codenamed FReD that is aimed at ~100%* source level compatible overhaul
>>> of std.regex, that uses better implementation techniques, provides
>>> modern Unicode support and common syntax riches.
>>>
>>> I think it's time for a public beta release, since it _should_ be ready
>>> for mainstream usage. There are some rough edges, and a couple issues
>>> that I'm aware of but they are nowhere in realistic use cases.
>>>
>>> In order to avoid unexpected regressions I'd be glad if current
>>> std.regex users do try it for their projects/tests.
>>> To get a small no-crap-included beta package see download section of
>>> https://github.com/blackwhale/FReD for .7zs.
>>> I'll upload newer packages as bugs get exposed and fixed.  
>>> Alternatively,
>>> if you a comfortable with git you may just git clone entire repo. Some
>>> helpful notes (same as README) can be found here :
>>> https://github.com/blackwhale/FReD/wiki/Beta-release
>>>
>>> Caveats:
>>> In order for it compile a tiny change to 2.054 source is needed (no  
>>> need
>>> to recompile Phobos! it's only in templates):
>>> patch std.algorithm.cmp according to this diff
>>> https://github.com/D-Programming-Language/phobos/pull/176/files#L0L4631
>>> <https://github.com/D-Programming-Language/phobos/pull/176/files#L0L4633>  
>>> and to get CTFE features working add if(!__ctfe) listed in the next  
>>> diff
>>> on the same webpage.
>>> (this is already upstream, so if you're using a fork of phobos just  
>>> pull
>>> this in)
>>>
>>> * some API problems might lead to a breaking change, though it didn't
>>> happen in this release
>>
>> I have a suggestion, make RegexMatch implicitly convertible to bool,  
>> indicating if there was a match or not.
>>
> Interesting idea, one problem with it is that I want this:
>
> auto m = match("bleh", "bleh");
> writeln(m);
>
> to actually print "bleh", not true

Without actually looking at the code, why wouldn't something like this  
work?

struct RegexMatch
{
    ...
    string toString() {...}
    opCast(T : bool)() {...}
}

This isn't an implicit cast, but it will work for conditional statements.

-Steve