shorten ( n seq -- ) - Factor Documentation

Vocabulary
sequences

Inputs and outputs

n	an integer
seq	a sequence

Word description
Shortens a Resizable sequence implementation sequence to be n elements long.

Examples

USING: sequences prettyprint kernel ;
V{ 1 2 3 4 5 } 3 over shorten .
V{ 1 2 3 }

Definition

IN: sequences

GENERIC: shorten ( n seq -- )

Methods

USING: accessors growable kernel math sequences
sequences.private ;

M: growable shorten
    bounds-check-head 2dup length <
    [ 2dup contract 2dup length<< ] when 2drop ; inline


USING: kernel math sequences ;

M: sequence shorten
    2dup length < [ set-length ] [ 2drop ] if ; inline