?last ( seq -- elt/f )
Factor handbook » The language » Collections » Sequence operations » Accessing sequence elements

Prev:	last ( seq -- elt )
Next:	first2 ( seq -- first second )

Vocabulary
sequences

Inputs

seq	a sequence

Outputs

elt/f

an object or f

Word description
A forgiving version of last. If the sequence is empty, or if the sequence is f, simply outputs f.

Definition

USING: kernel math sequences.private ;

IN: sequences

: ?last ( seq -- elt/f )
    index-of-last over 0 < [ 2drop f ] [ nth-unsafe ] if ;
    inline