std.regex is fat

[Chris Katko]

On Friday, 12 October 2018 at 13:42:34 UTC, Alex wrote:
> On Friday, 12 October 2018 at 13:25:33 UTC, Chris Katko wrote:
>> Like, insanely fat.
>>
>> All I wanted was a simple regex. The second include a regex 
>> function, my program would no longer compile "out of memory 
>> for fork".
>>
>> /usr/bin/time -v reports it went from 150MB of RAM for D, 
>> DAllegro, and Allegro5.
>>
>> To over 650MB of RAM, and from 1.5 seconds to >5.5 seconds to 
>> compile. Now I have to close all my Chrome tabs just to 
>> compile.
>>
>> Just for one line of regex. And I get it, it's the overhead of 
>> the library import, not the single line. But good gosh, more 
>> than 3X the RAM of the entire project for a single library 
>> import?
>>
>> Something doesn't add up!
>
> Hm... maybe, you run into this:
> https://forum.dlang.org/post/mailman.3091.1517866806.9493.digitalmars-d@puremagic.com

So wait, if their solution was to simply REMOVE std.regex from 
isEmail. That doesn't solve the regex problem at all. And from 
what I read in that thread, this penalty is paid per template 
INSTANTIATION which could explode.

  1 - Does anyone know WHY it's so incredibly fat?

  2 - If this isn't going to be fixed anytime soon, shouldn't 
there be a DISCLAIMER on the documentation? (+potential 
workarounds like keeping regex queries in their own file.)

I mean, this kind of thing shouldn't require looking through 
forums. It's a clear bug, and if it's a WONTFIX (even 
temporarily), it should be documented clearly as such.

If I'm running into this issue, how many other people already 
did, and possibly even gave up on using D?