maybe-set-at ( value key assoc -- changed? )

Vocabulary

assocs

Inputs

value	an object
key	an object
assoc	an object

Outputs

changed?

an object

Definition

USING: kernel ;

IN: assocs

: maybe-set-at ( value key assoc -- changed? )
    3dup at*
    [ = [ 3drop f ] [ set-at t ] if ] [ 2drop set-at t ] if ;