57 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			Factor
		
	
	
			
		
		
	
	
			57 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			Factor
		
	
	
! Copyright (C) 2004, 2010 Slava Pestov.
 | 
						|
! See http://factorcode.org/license.txt for BSD license.
 | 
						|
USING: words accessors sequences kernel assocs combinators
 | 
						|
classes classes.private classes.algebra classes.algebra.private
 | 
						|
classes.builtin namespaces arrays math quotations ;
 | 
						|
IN: classes.intersection
 | 
						|
 | 
						|
PREDICATE: intersection-class < class
 | 
						|
    "metaclass" word-prop intersection-class eq? ;
 | 
						|
 | 
						|
<PRIVATE
 | 
						|
 | 
						|
: intersection-predicate-quot ( members -- quot )
 | 
						|
    [
 | 
						|
        [ drop t ]
 | 
						|
    ] [
 | 
						|
        unclip "predicate" word-prop swap [
 | 
						|
            "predicate" word-prop [ dup ] [ not ] surround
 | 
						|
            [ drop f ]
 | 
						|
        ] { } map>assoc alist>quot
 | 
						|
    ] if-empty ;
 | 
						|
 | 
						|
: define-intersection-predicate ( class -- )
 | 
						|
    dup participants intersection-predicate-quot define-predicate ;
 | 
						|
 | 
						|
M: intersection-class update-class define-intersection-predicate ;
 | 
						|
 | 
						|
M: intersection-class rank-class drop 5 ;
 | 
						|
 | 
						|
M: intersection-class instance?
 | 
						|
    "participants" word-prop [ instance? ] with all? ;
 | 
						|
 | 
						|
M: intersection-class normalize-class
 | 
						|
    participants <anonymous-intersection> normalize-class ;
 | 
						|
 | 
						|
M: intersection-class (flatten-class)
 | 
						|
    participants <anonymous-intersection> (flatten-class) ;
 | 
						|
 | 
						|
! Horribly inefficient and inaccurate
 | 
						|
: intersect-flattened-classes ( seq1 seq2 -- seq3 )
 | 
						|
    ! Only keep those in seq1 that intersect something in seq2.
 | 
						|
    [ [ classes-intersect? ] with any? ] curry filter ;
 | 
						|
 | 
						|
M: anonymous-intersection (flatten-class)
 | 
						|
    participants>> [ full-cover ] [
 | 
						|
        [ flatten-class keys ]
 | 
						|
        [ intersect-flattened-classes ] map-reduce
 | 
						|
        [ dup set ] each
 | 
						|
    ] if-empty ;
 | 
						|
 | 
						|
PRIVATE>
 | 
						|
 | 
						|
: define-intersection-class ( class participants -- )
 | 
						|
    [ [ f f ] dip intersection-class define-class ]
 | 
						|
    [ drop update-classes ]
 | 
						|
    2bi ;
 |