Evaluating Regular Expressions at compile time in D

Question

Is there a way to evaluate regular expressions in D, at compile time?

score 2 · Answer 1 · answered Apr 29 '14 at 21:02

2

Use a static variable of type std.regex.ctRegex.

answered Apr 29 '14 at 21:02

Adam D. Ruppe

I already tried that, but the returned Captures aren't available at compile time, and casting them immutable will not allow me to get the result. – Jeroen Apr 29 '14 at 21:07
What exactly are you doing? – Adam D. Ruppe Apr 29 '14 at 21:17
Evaluating if a string matches a regex and fetch the match. – Jeroen Apr 29 '14 at 21:17
2

Hmm, interesting, the straightforward CTFE of plain regex doesn't work since it uses malloc! Rewriting it is a bit of a pain for that to, blargh. – Adam D. Ruppe Apr 29 '14 at 22:18
I took a shot at it but then you run into issues with casting pointers, which doesn't work with CTFE... – Vladimir Panteleev Apr 29 '14 at 22:27
1

Yeah, and it does this throughout the file too. I think the best option here is to not use regex here... – Adam D. Ruppe Apr 29 '14 at 22:29
@AdamD.Ruppe Any alternatives? – Jeroen Apr 30 '14 at 10:25
The best option that comes to mind is to break down the regex into simpler string functions like indexOf etc. – Adam D. Ruppe Apr 30 '14 at 15:06

1 Answers1