On Monday, 5 February 2018 at 21:27:57 UTC, H. S. Teoh wrote:
One of my D projects for the past while has been taking
unusually long times to compile. This morning, I finally
decided to sit down and figure out exactly why. What I found
was rather disturbing:
------
import std.regex;
void main() {
auto re = regex(``);
}
------
Compile command: time dmd -c test.d
Output:
------
real 0m3.113s
user 0m2.884s
sys 0m0.226s
------
Comment out the call to `regex()`, and I get:
------
real 0m0.285s
user 0m0.262s
sys 0m0.023s
------
Clearly, something is wrong if the mere act of compiling a
regex causes a 4-line program to take *3 seconds* to compile,
where normally dmd takes less than a second.
Thank you for this finding!
I was wondering why my little vibe.d project started to take
approximately twice the
time to compile, and because of making a mistake in my test
setup, even my minimal
program still included the file containing the regex. So that
even reducing the used
code to a minimum the compilation time was ~7 sec compared to
less than 4 seconds.
Would be cool if we could get fast compilation of regex.
I am coming from using scripting languages (perl and ruby) using
regex a lot, so that this is really disappointing for me.
Beginner question:
How to split my project, to compile the regex part separately as
a lib and just link them?
