1 ! Copyright (C) 2004, 2008 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: arrays generic assocs hashtables inference kernel
4 math namespaces sequences words parser math.intervals
5 effects classes classes.algebra inference.dataflow
6 inference.backend combinators accessors ;
11 ! A constraint is a statement about a value.
13 ! We need a notion of equality which doesn't recurse so cannot
14 ! infinite loop on circular data
15 GENERIC: eql? ( obj1 obj2 -- ? )
17 M: number eql? number= ;
19 ! Maps constraints to constraints
22 TUPLE: literal-constraint literal value ;
24 C: <literal-constraint> literal-constraint
26 M: literal-constraint equal?
27 over literal-constraint? [
28 [ [ literal>> ] bi@ eql? ]
33 TUPLE: class-constraint class value ;
35 C: <class-constraint> class-constraint
37 TUPLE: interval-constraint interval value ;
39 C: <interval-constraint> interval-constraint
41 GENERIC: apply-constraint ( constraint -- )
42 GENERIC: constraint-satisfied? ( constraint -- ? )
44 : `input ( n -- value ) node get in-d>> nth ;
45 : `output ( n -- value ) node get out-d>> nth ;
46 : class, ( class value -- ) <class-constraint> , ;
47 : literal, ( literal value -- ) <literal-constraint> , ;
48 : interval, ( interval value -- ) <interval-constraint> , ;
50 M: f apply-constraint drop ;
52 : make-constraints ( node quot -- constraint )
53 [ swap node set call ] { } make ; inline
55 : set-constraints ( node quot -- )
57 unclip [ 2array ] reduce
58 apply-constraint ; inline
60 : assume ( constraint -- )
61 constraints get at [ apply-constraint ] when* ;
63 ! Variables used by the class inferencer
65 ! Current value --> literal mapping
66 SYMBOL: value-literals
68 ! Current value --> interval mapping
69 SYMBOL: value-intervals
71 ! Current value --> class mapping
74 : value-interval* ( value -- interval/f )
75 value-intervals get at ;
77 : set-value-interval* ( interval value -- )
78 value-intervals get set-at ;
80 : intersect-value-interval ( interval value -- )
81 [ value-interval* interval-intersect ] keep
84 M: interval-constraint apply-constraint
85 [ interval>> ] [ value>> ] bi intersect-value-interval ;
87 : set-class-interval ( class value -- )
89 >r "interval" word-prop r> over
90 [ set-value-interval* ] [ 2drop ] if
93 : value-class* ( value -- class )
94 value-classes get at object or ;
96 : set-value-class* ( class value -- )
98 dup value-intervals get at [
99 2dup set-class-interval
101 2dup <class-constraint> assume
103 value-classes get set-at ;
105 : intersect-value-class ( class value -- )
106 [ value-class* class-and ] keep set-value-class* ;
108 M: class-constraint apply-constraint
109 [ class>> ] [ value>> ] bi intersect-value-class ;
111 : literal-interval ( value -- interval/f )
112 dup real? [ [a,a] ] [ drop f ] if ;
114 : set-value-literal* ( literal value -- )
116 [ >r class r> set-value-class* ]
117 [ >r literal-interval r> set-value-interval* ]
118 [ <literal-constraint> assume ]
119 [ value-literals get set-at ]
122 M: literal-constraint apply-constraint
123 [ literal>> ] [ value>> ] bi set-value-literal* ;
125 ! For conditionals, an assoc of child node # --> constraint
126 GENERIC: child-constraints ( node -- seq )
128 GENERIC: infer-classes-before ( node -- )
130 GENERIC: infer-classes-around ( node -- )
132 GENERIC: infer-classes-after ( node -- )
134 M: node infer-classes-before drop ;
136 M: node infer-classes-after drop ;
138 M: node child-constraints
140 dup zero? [ drop f ] [ f <repetition> ] if ;
142 : value-literal* ( value -- obj ? )
143 value-literals get at* ;
145 M: literal-constraint constraint-satisfied?
146 dup value>> value-literal*
147 [ swap literal>> eql? ] [ 2drop f ] if ;
149 M: class-constraint constraint-satisfied?
150 [ value>> value-class* ] [ class>> ] bi class<= ;
152 M: pair apply-constraint
153 first2 2dup constraints get set-at
154 constraint-satisfied? [ apply-constraint ] [ drop ] if ;
156 M: pair constraint-satisfied?
157 first constraint-satisfied? ;
159 : valid-keys ( seq assoc -- newassoc )
160 extract-keys [ nip ] assoc-filter f assoc-like ;
162 : annotate-node ( node -- )
163 #! Annotate the node with the currently-inferred set of
166 [ value-intervals get valid-keys >>intervals ]
167 [ value-classes get valid-keys >>classes ]
168 [ value-literals get valid-keys >>literals ]
172 : intersect-classes ( classes values -- )
173 [ intersect-value-class ] 2each ;
175 : intersect-intervals ( intervals values -- )
176 [ intersect-value-interval ] 2each ;
178 : predicate-constraints ( class #call -- )
180 ! If word outputs true, input is an instance of class
183 \ f class-not 0 `output class,
186 ! If word outputs false, input is not an instance of class
188 class-not 0 `input class,
193 : compute-constraints ( #call -- )
194 dup param>> "constraints" word-prop [
197 dup param>> "predicating" word-prop dup
198 [ swap predicate-constraints ] [ 2drop ] if
201 : compute-output-classes ( node word -- classes intervals )
202 dup param>> "output-classes" word-prop
203 dup [ call ] [ 2drop f f ] if ;
205 : output-classes ( node -- classes intervals )
206 dup compute-output-classes >r
207 [ ] [ param>> "default-output-classes" word-prop ] ?if
210 : intersect-values ( classes intervals values -- )
211 tuck [ intersect-classes ] [ intersect-intervals ] 2bi* ;
213 M: #call infer-classes-before
214 [ compute-constraints ]
215 [ [ output-classes ] [ out-d>> ] bi intersect-values ] bi ;
217 : input-classes ( #call -- classes )
218 param>> "input-classes" word-prop ;
220 M: #call infer-classes-after
221 [ input-classes ] [ in-d>> ] bi intersect-classes ;
223 M: #push infer-classes-before
224 out-d>> [ [ value-literal ] keep set-value-literal* ] each ;
226 M: #if child-constraints
228 \ f class-not 0 `input class,
232 M: #dispatch child-constraints
234 children>> length [ 0 `input literal, ] each
237 M: #declare infer-classes-before
238 [ param>> ] [ in-d>> ] bi
239 [ intersect-value-class ] 2each ;
241 DEFER: (infer-classes)
243 : infer-children ( node -- )
244 [ children>> ] [ child-constraints ] bi [
246 value-classes [ clone ] change
247 value-literals [ clone ] change
248 value-intervals [ clone ] change
249 constraints [ clone ] change
255 : pad-all ( seqs elt -- seq )
256 >r dup [ length ] map supremum r> [ pad-left ] 2curry map ;
258 : (merge-classes) ( nodes -- seq )
260 first node-input-classes
262 [ node-input-classes ] map null pad-all flip
263 [ null [ class-or ] reduce ] map
266 : set-classes ( seq node -- )
267 out-d>> [ set-value-class* ] 2reverse-each ;
269 : merge-classes ( nodes node -- )
270 >r (merge-classes) r> set-classes ;
272 : set-intervals ( seq node -- )
273 out-d>> [ set-value-interval* ] 2reverse-each ;
275 : merge-intervals ( nodes node -- )
277 [ node-input-intervals ] map f pad-all flip
278 [ dup first [ interval-union ] reduce ] map
281 : annotate-merge ( nodes #merge/#entry -- )
282 [ merge-classes ] [ merge-intervals ] 2bi ;
284 : merge-children ( node -- )
285 dup node-successor dup #merge? [
286 swap active-children dup empty?
287 [ 2drop ] [ swap annotate-merge ] if
290 : classes= ( inferred current -- ? )
291 2dup min-length [ tail* ] curry bi@ sequence= ;
295 SYMBOL: nested-labels
297 : annotate-entry ( nodes #label -- )
298 >r (merge-classes) r> node-child
299 2dup node-output-classes classes=
300 [ 2drop ] [ set-classes fixed-point? off ] if ;
302 : init-recursive-calls ( #label -- )
303 #! We set recursive calls to output the empty type, then
304 #! repeat inference until a fixed point is reached.
305 #! Hopefully, our type functions are monotonic so this
306 #! will always converge.
307 returns>> [ dup in-d>> [ null ] { } map>assoc >>classes drop ] each ;
309 M: #label infer-classes-before ( #label -- )
310 [ init-recursive-calls ]
311 [ [ 1array ] keep annotate-entry ] bi ;
313 : infer-label-loop ( #label -- )
315 dup node-child (infer-classes)
316 dup [ calls>> ] [ suffix ] [ annotate-entry ] tri
317 fixed-point? get [ drop ] [ infer-label-loop ] if ;
319 M: #label infer-classes-around ( #label -- )
320 #! Now merge the types at every recursion point with the
324 [ nested-labels get push ]
326 [ infer-classes-before ]
328 [ drop nested-labels get pop* ]
332 : find-label ( param -- #label )
333 param>> nested-labels get [ param>> eq? ] with find nip ;
335 M: #call-label infer-classes-before ( #call-label -- )
336 [ find-label returns>> (merge-classes) ] [ out-d>> ] bi
337 [ set-value-class* ] 2each ;
339 M: #return infer-classes-around
340 nested-labels get length 0 > [
341 dup param>> nested-labels get peek param>> eq? [
342 [ ] [ node-input-classes ] [ in-d>> [ value-class* ] map ] tri
345 [ in-d>> value-classes get valid-keys ] keep
348 ] [ call-next-method ] if
349 ] [ call-next-method ] if ;
351 M: object infer-classes-around
353 [ infer-classes-before ]
355 [ infer-classes-after ]
360 : (infer-classes) ( node -- )
362 [ infer-classes-around ]
363 [ node-successor ] bi
367 : infer-classes-with ( node classes literals intervals -- )
369 V{ } clone nested-labels set
370 H{ } assoc-like value-intervals set
371 H{ } assoc-like value-literals set
372 H{ } assoc-like value-classes set
373 H{ } clone constraints set
377 : infer-classes ( node -- node )
378 dup f f f infer-classes-with ;
380 : infer-classes/node ( node existing -- )
381 #! Infer classes, using the existing node's class info as a
383 [ classes>> ] [ literals>> ] [ intervals>> ] tri