(class-and) ( first second -- class )


Vocabulary
classes.algebra.private

Inputs
firstan object
secondan object


Outputs
classan object


Definition
USING: classes.algebra combinators kernel math.order ;

IN: classes.algebra.private

: (class-and) ( first second -- class )
2dup compare-classes {
{ +lt+ [ drop ] }
{ +gt+ [ nip ] }
{ +eq+ [ nip ] }
{
+incomparable+
[
2dup classes-intersect? [
[ normalize-class ] bi@ {
~array~
~array~
~array~
~array~
~quotation~
} cond
] [ 2drop null ] if
]
}
} case ;