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[Sergey Gromov]

Sat, 11 Oct 2008 09:05:26 -0500,
Andrei Alexandrescu wrote:
> Sergey Gromov wrote:
> > Sat, 11 Oct 2008 12:16:43 +0200,
> > Sascha Katzner wrote:
> >> - The StringBuilder in the Java version is *much* faster because it 
> >> doesn't have to allocate a new memory block in each step. You can use a 
> >> similar class in D too, without the need of a special string class/object.
> > 
> > I agree here.  Both word tango.text.Util.split and runConcatenateTest 
> > use default array appending which is currently dead slow.  Benji, to 
> > actually compare the speed of string operations you better use one of 
> > array builders discussed in this group.
> 
> If anyone wants to try it, I'm pasting the draft version of Appender 
> from std.array below.

I took the trouble to port your Appender to DMD 1.033 and fixed Benji's 
benchmark to use it.  Here's my timings, best of 5 runs each:

D: 0.37s
Java: 1.05s

Here are sample logs from both:

> >StringTest2.exe
> time to load file: 0.008575 seconds
> iterated through 3921852 characters, and found 910473 spaces in 0.051324 seconds
> String.indexOf(): found 31318 instances of 'the' in 0.033293 seconds
> replaced 31318 instances of 'the' with 'XXXX' in 0.085224 seconds
> split text into 910474 words in 0.109966 seconds
> concatenated 910474 words (with 3921853 chars) in 0.085061 seconds
> overall test duration: 0.374258 seconds

> >java StringTest
> time to load file: 0.104578655 seconds
> iterated through 3921852 characters, and found 910473 spaces in 0.026583267 seconds
> String.indexOf(): found 31318 instances of 'the' in 0.014550173 seconds
> replaced 31318 instances of 'the' with 'XXXX' in 0.212482871 seconds
> split text into 910474 words in 0.452282064 seconds
> concatenated 910474 words (with 3921853 chars) in 0.220009526 seconds
> overall test duration: 1.054729581 seconds

Who rules?  ;D