On 2/5/13 5:44 AM, Jonathan M Davis wrote:
On Tuesday, February 05, 2013 09:14:35 Jacob Carlborg wrote:
On 2013-02-05 04:22, Andrei Alexandrescu wrote:
Suggestion: take lexer.c and convert it to D. Should take one day, and
you'll have performance on par.
There's reason for why nobody has just extract the lexer from DMD. It
will probably take more than a day just to extract the lexer to be able
to use it without the rest of DMD.
There are basic ideas about how it works which are obviously good and should
be in the finished product in D, but it's not range-based, which forces you to
do things differently. It's also not configurable, which forces you to do things
differently.
If it could be ported as-is and then compared for speed, then that would be a
great test, since it would be able to show how much of the speed problem is
purely a compiler issue as opposed to a design issue, but you wouldn't be able
to actually use it for anything more than what Brian is doing with his
performance testing, because as you point out, it's too integrated into dmd.
It _would_ be valuable though as a performance test of the compiler.
As far as I could tell the dependencies of the lexer are fairly
contained (util, token, identifier) and conversion to input range is
immediate.
Andrei
