count-tail ( seq quot -- n )

Vocabulary

sequences.extras

Inputs

seq	a sequence
quot	a quotation

Outputs

n	an integer

Word description

Count the number of values from the end of seq that return a truthy value when passed into quot.

Definition

USING: kernel math sequences ;

IN: sequences.extras

: count-tail ( seq quot -- n )
    [ not ] compose [ find-last drop ] keepd length swap
    [ - 1 - ] when* ; inline