[racket] (define best (compose car sort))

Yes! I looked in the documentation, but I missed it.

Gustavo


On Sat, Jan 18, 2014 at 5:46 PM, Matthias Felleisen
<matthias at ccs.neu.edu> wrote:
>
> Do you want argmax
>
>
> On Jan 18, 2014, at 11:57 AM, Gustavo Massaccesi wrote:
>
>> I extended one of the Rosetta code task: Levenshtein
>> distance/Alignment:
>> http://rosettacode.org/wiki/Levenshtein_distance/Alignment to show the
>> alignment.
>>
>> I needed a function that finds the “best” item in a list. It’s like
>> sort but it only finds the first one:
>>
>> #lang racket
>> (define best (compose car sort))
>>
>> (define data '((3 "three") (4 "four") (2 "two") (1 "one"))
>>
>> (best data < #:key car) ;==> (1 "one")
>> (best data > #:key car) ;==> (4 "four")
>>
>> (best data string<? #:key cadr) ;==> (4 "four")
>> (best data string>? #:key cadr) ;==> (2 "two")
>>
>> It’s not very efficient, but I needed it only for n=3.
>>
>> I could have written an efficient version by hand, but I it was only
>> an auxiliary function and I wanted to keep the task as short as
>> possible.
>>
>> Did anyone use a similar function in another program? Can the
>> efficient version be added to the standard library? (Is it a good idea
>> to add yet another function to the standard library?)
>>
>> Gustavo
>>
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>