[Jprogramming] sorting using verb returing a boolean

['Pascal Jasmin' via Programming]

 The same output of your quoted "program"

\:~ _10 1 10 20 _30 15 25 30 0

30 25 20 15 10 1 0 _10 _30

I may have misunderstood your original question, based on subject line.  You appear to want to sort card hands.
You would want to encode cards as integers, where 2-A maps to 0-13.  It is a good J datastructure if you wanted suits to represent it as a "handsize" by 2 shaped table, and 3 dimensional J data would store multiple items of hands.
> 2AAAA is greater than A2222> 23452 is lesser than 23453
from a lexicographical sort perspective,

(0 12 12 12 12) ([ -: {.@:(\:~)@:,:) 12 0 0 0 0
0 NB.  2AAAA is greater than A2222 ... is false from a descending lexographical sort perspective.
What it appears your desired verb to be is to assess the value/rank of poker hands.  The scoring function for poker hands can/is be monadic.
compareV =: (>&) NB. adverb that will compare 2 scoring functions applied to each dyadic argument.
pokerhandscoringfunction compareV





    On Thursday, December 21, 2023 at 10:17:41 a.m. EST, 'Viktor Grigorov' via Programming <programming at jsoftware.com> wrote:  
 
 Maybe a table, summation and a sort using that:

   (/: ([:+/(>/]))) _10 1 10 20 _30 15 25 30 0
Can't imagine that being efficient, but it's better than nothing. The verb I'd defined can't deal with rank 2 nouns anyways.

Dec 21, 2023, 14:21 by programming at jsoftware.com:

> Not quite though. Had I 5 hands, that'd be !4 booleans.
>
>
> Dec 21, 2023, 14:11 by programming at jsoftware.com:
>
>>
>> 1 0 0 1 0 /:~ i.5
>>
>> 1 2 4 0 3
>>
>>
>>  On Thursday, December 21, 2023 at 09:03:34 a.m. EST, 'Viktor Grigorov' via Programming <programming at jsoftware.com> wrote: 
>>  
>>  Hey,
>>
>> Is there an easy way to sort an array with verb  returning either 0 or 1, like the comparison primitives? 
>>
>> The verb that I'd in mind relates to the 2023's advent of code's day 7: given two equal length hands, which one has the first high card. Which one can write as:
>>
>>    'K2345' ( 2 | 0 { [: I. [: , [: (<,.>)/ ,: & ('23456789TJQKA'i.]) ) 'KJ2KA'
>> 0 NB. here meaning left is not greater right
>>
>> Cheers,
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>
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