?3guard ( ..a x y z quot: ( ..a x y z -- ..b ? ) -- ..b x/f y/f z/f ? )

Vocabulary

combinators.extras

Inputs

x	an object
y	an object
z	an object
quot	a quotation with stack effect ( ..a x y z -- ..b ? )

Outputs

x/f	an object
y/f	an object
z/f	an object
?	an object

Definition

USING: kernel ;

IN: combinators.extras

: ?3guard
    ( ..a x y z quot: ( ..a x y z -- ..b ? ) -- ..b x/f y/f z/f ? )
    3check [ t ] [ 3drop f f f f ] if ; inline