:: ([item>][>field]) ( tuple hash quot-pair -- quot1 quot2 )
    quot-pair first2 :> ( key setter )
    key [ hash at ] compose
    setter [ tuple drop ] compose ;

: hash-item>field ( tuple hash pair -- tuple )
    [ dup ] 2dip ([item>][>field])
    [ (( -- obj )) call-effect ] dip
    '[ _ (( obj -- )) call-effect ] when* ;