A few notes on choosing between Go and D for a quick project

[weaselcat via Digitalmars-d]

On Thursday, 19 March 2015 at 16:59:36 UTC, Ola Fosheim Grøstad 
wrote:
> On Thursday, 19 March 2015 at 00:42:51 UTC, weaselcat wrote:
>> On Wednesday, 18 March 2015 at 12:59:17 UTC, bearophile wrote:
>>> High level constructs in D are often slower than low-level 
>>> code, so in some cases you don't want to use them.
>>
>> I actually found that LDC does an _amazing_ job of optimizing 
>> high level constructs and converting "low level" code to 
>> higher level functional code resulted in minor speedups in a 
>> lot of cases.
>>
>>
>> (Other performance benefits include the algorithm primitives 
>> being extensively optimized in phobos.)
>
> If the code/compiler generates suboptimal code in the first 
> place then improvements can be somewhat random. But if you 
> write code with good cache locality, filling the pipeline 
> properly then  there is no alternative to going low level.
>
> Btw, take a look at this:
> http://stackoverflow.com/questions/28922323/improving-line-wise-i-o-operations-in-d
>
> That's really bad marketing...

python:
time python2 wc.py 
enwiki-latest-pages-articles1.xml-p000000010p000010000
There are 1245473 lines
python2 wc.py 
enwiki-latest-pages-articles1.xml-p000000010p000010000  0.21s 
user 0.08s system 99% cpu 0.294 total

wc -l:
time wc -l enwiki-latest-pages-articles1.xml-p000000010p000010000
1245472 enwiki-latest-pages-articles1.xml-p000000010p000010000
wc -l enwiki-latest-pages-articles1.xml-p000000010p000010000  
0.05s user 0.02s system 96% cpu 0.072 total


iterative version:
ldc -O5 -inline -release -boundscheck=off wc.d
time ./wc
There are 1245473 lines.
./wc enwiki-latest-pages-articles1.xml-p000000010p000010000  
0.59s user 0.07s system 99% cpu 0.661 total

functional version:
writeln("There are ", 
(cast(string)read(args[1])).splitter('\n').array.length, " 
lines.");

ldc -O5 -inline -release -boundscheck=off wc.d
time ./wc enwiki-latest-pages-articles1.xml-p000000010p000010000
There are 1245473 lines.
./wc enwiki-latest-pages-articles1.xml-p000000010p000010000  
0.04s user 0.08s system 98% cpu 0.125 total


ahem
>> I actually found that LDC does an _amazing_ job of optimizing 
>> high level constructs and converting "low level" code to 
>> higher level functional code resulted in minor speedups in a 
>> lot of cases.