check-widthed ( bits #bits -- bits #bits )

Vocabulary

bitstreams

Inputs

bits	an object
#bits	an object

Outputs

bits	an object
#bits	an object

Definition

USING: combinators.short-circuit kernel math ;

IN: bitstreams

: check-widthed ( bits #bits -- bits #bits )
    2dup {
        [ nip 0 < ]
        [ { [ nip 0 = ] [ drop 0 = not ] } 2&& ]
        [
            swap
            [ drop f ] [ dup 0 < [ neg ] when log2 <= ] if-zero
        ]
    } 2|| [ invalid-widthed ] when ;