Re: [MIT-Scheme-devel] string-head!

[Chris Hanson]

That case isn't such a big deal, but the general string-accumulator
pattern gets used in a bunch of places where the overhead is very low,
such as in utf-8 conversion.  I'd like to be able to use string-head!
there too.

On Thu, Sep 24, 2009 at 1:48 PM, Joe Marshall <address@hidden> wrote:
> On Thu, Sep 24, 2009 at 12:59 PM, Taylor R Campbell <address@hidden> wrote:
>>  In any case, I thought the point of
>> STRING-HEAD! was to reduce pressure on the garbage collector, not to
>> reduce the time spent switching between Scheme land and C land, and we
>> can reduce pressure on the garbage collector just by using the
>> primitive SET-STRING-MAXIMUM-LENGTH! if it's available.
>
> Has anyone measured the performance difference between smashing
> the string head and just taking a substring?  I'd bet it's a pretty minimal
> improvement against the background of the other things that happen during I/O.
>
> --
> ~jrm
>