Re: CSV extension status

[Manuel Collado]

El 18/05/2021 a las 23:38, Manuel Collado escribió:
> El 18/05/2021 a las 17:33, Andrew J. Schorr escribió:
> ..
> > For those who want simple, read-only access to CSV documents, my
> > gut instinct is that an input parser library would be a better and
> > more robust solution. In particular, the splitting and
> > reconstruction of the record with OFS seems a bit slow and fragile
> > to me.
>
> If your code never rewrites the data this reconstruction will never take
> place. And if it does, the reconstruction is certainly done in the gawk
> core, not in the extension. Do you think the gawk core is slow and
> fragile? ;-)

Oh! Sorry. I've just realized that you are probably talking about how 
csvmode.awk rebuilds the record with clean values delimited by CSVOFS.
Of course, you are right. On simple cases demangling CSV and composing 
the clean values almost duplicates the processing time.

But, surprisingly, even in that case the pure gawk library beats the 
API-based extension. A simple test based on your previous age/weight 
example, with a sample of 10000 random values gives:

-- with csvmode.awk
CSVMODE = 1 (CSV fragments)
real    0m0.151s
user    0m0.109s
sys     0m0.015s

CSVMODE = -1 (clean values)
real    0m0.253s
user    0m0.203s
sys     0m0.030s

-- with gawk-csv (clean values)
real    0m0.980s
user    0m0.312s
sys     0m0.672s

Don't know the reason of this unexpected result.

Regards.
--
Manuel Collado - http://mcollado.z15.es