Speed of csvReader

[Jesse Phillips via Digitalmars-d-learn]

On Thursday, 21 January 2016 at 09:39:30 UTC, data pulverizer 
wrote:
> R takes about half as long to read the file. Both read the data 
> in the "equivalent" type format. Am I doing something incorrect 
> here?

CsvReader hasn't been compared and optimized from other CSV 
readers. It does have allocation for the parsed string (even if 
it isn't changed) and it does a number of validation checks.

You may get some improvement disabling the CSV validation, but 
again this wasn't tested for performance.

     csvReader!(string,Malformed.ignore)(str)

Generally people recommend using GDC/LCD if you need resulting 
executable performance, but csvReader being slower isn't the most 
surprising.

Before submitting my library to phobos I had started a CSV reader 
that would do no allocations and instead return the string slice. 
This wasn't completed and so it never had performance testing 
done against it. It could very well be slower.

https://github.com/JesseKPhillips/JPDLibs/blob/csvoptimize/csv/csv.d

My original CSV parser was really slow because I parsed the 
string twice.