find-integer-from ( ... i n quot: ( ... i -- ... ? ) -- ... i/f )

Vocabulary

math

Inputs

i	an integer
n	an integer
quot	a quotation with stack effect ( ... i -- ... ? )

Outputs

i/f	an integer or f

Word description

Applies the quotation to each integer from i up to n, excluding n. Iteration stops when the quotation outputs a true value or the end is reached. If the quotation yields a true value for some integer, this word outputs that integer. Otherwise, this word outputs f.

Notes

This word is used to implement find-integer and find.

Definition

USING: kernel ;

IN: math

: find-integer-from
    ( ... i n quot: ( ... i -- ... ? ) -- ... i/f )
    2over < [
        [ nip call ] 3check
        [ 2drop ] [ [ 1 + ] 2dip find-integer-from ] if
    ] [ 3drop f ] if ; inline recursive