value-at* ( value assoc -- key/f ? )
Factor handbook » The language » Collections » Associative mapping operations » Transposed assoc operations

Prev:value-at ( value assoc -- key/f )
Next:value? ( value assoc -- ? )


Vocabulary
assocs

Inputs
valuean object
assocan assoc


Outputs
key/fthe key associated to the value or f
?a boolean


Word description
Looks up the key associated with a value. The boolean flag can decide between the case of a missing key, and a key of f.

Definition

GENERIC: value-at* ( value assoc -- key/f ? )


Methods