1 ! Copyright (C) 2008, 2010 Slava Pestov.
2 ! See https://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays assocs classes.algebra
4 compiler.tree.propagation.copy compiler.tree.propagation.info
5 kernel namespaces sequences ;
6 IN: compiler.tree.propagation.constraints
10 GENERIC: assume* ( constraint -- )
11 GENERIC: satisfied? ( constraint -- ? )
15 M: object satisfied? drop f ;
17 : assume ( constraint -- ) dup satisfied? [ drop ] [ assume* ] if ;
19 TUPLE: true-constraint value ;
21 : =t ( value -- constraint ) resolve-copy true-constraint boa ;
23 : follow-implications ( constraint -- )
24 constraints get assoc-stack [ assume ] when* ;
26 M: true-constraint assume*
27 [ \ f class-not <class-info> swap value>> refine-value-info ]
28 [ follow-implications ]
31 M: true-constraint satisfied?
33 [ class>> true-class? ] [ drop f ] if ;
35 TUPLE: false-constraint value ;
37 : =f ( value -- constraint ) resolve-copy false-constraint boa ;
39 M: false-constraint assume*
40 [ \ f <class-info> swap value>> refine-value-info ]
41 [ follow-implications ]
44 M: false-constraint satisfied?
46 [ class>> false-class? ] [ drop f ] if ;
48 TUPLE: class-constraint value class ;
50 : is-instance-of ( value class -- constraint )
51 [ resolve-copy ] dip class-constraint boa ;
53 M: class-constraint assume*
54 [ class>> <class-info> ] [ value>> ] bi refine-value-info ;
56 TUPLE: interval-constraint value interval ;
58 : is-in-interval ( value interval -- constraint )
59 [ resolve-copy ] dip interval-constraint boa ;
61 M: interval-constraint assume*
62 [ interval>> <interval-info> ] [ value>> ] bi refine-value-info ;
64 TUPLE: literal-constraint value literal ;
66 : is-equal-to ( value literal -- constraint )
67 [ resolve-copy ] dip literal-constraint boa ;
69 M: literal-constraint assume*
70 [ literal>> <literal-info> ] [ value>> ] bi refine-value-info ;
72 TUPLE: implication p q ;
76 : maybe-add ( elt seq -- seq' )
77 2dup member? [ nip ] [ swap suffix ] if ;
79 : assume-implication ( q p -- )
80 [ constraints get [ assoc-stack maybe-add ] 2keep last set-at ]
81 [ satisfied? [ assume ] [ drop ] if ] 2bi ;
83 M: implication assume*
84 [ q>> ] [ p>> ] bi assume-implication ;
86 TUPLE: equivalence p q ;
90 M: equivalence assume*
92 [ assume-implication ]
93 [ swap assume-implication ] 2bi ;
95 ! Conjunction constraints -- sequences act as conjunctions
96 M: sequence assume* [ assume ] each ;
98 : t--> ( constraint boolean-value -- constraint' ) =t swap --> ;
100 : f--> ( constraint boolean-value -- constraint' ) =f swap --> ;