check-slice ( from to seq -- from to seq )

Vocabulary

sequences

Inputs

from	a non-negative integer
to	a non-negative integer
seq	a sequence

Outputs

from	a non-negative integer
to	a non-negative integer
seq	a sequence

Word description

Ensures that from is less than or equal to to, and that both indices are within bounds for seq.

Errors

Throws a slice-error if the preconditions are not met.

Definition

USING: kernel math ;

IN: sequences

: check-slice ( from to seq -- from to seq )
    pick 0 < [ slice-error ] when 2dup length >
    [ slice-error ] when 2over > [ slice-error ] when ; inline