1 ! Copyright (C) 2005, 2008 Slava Pestov, Daniel Ehrenberg.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors kernel kernel.private slots.private math
4 math.private math.order ;
9 GENERIC: length ( seq -- n ) flushable
10 GENERIC: set-length ( n seq -- )
11 GENERIC: nth ( n seq -- elt ) flushable
12 GENERIC: set-nth ( elt n seq -- )
13 GENERIC: new-sequence ( len seq -- newseq ) flushable
14 GENERIC: new-resizable ( len seq -- newseq ) flushable
15 GENERIC: like ( seq exemplar -- newseq ) flushable
16 GENERIC: clone-like ( seq exemplar -- newseq ) flushable
18 : new-like ( len exemplar quot -- seq )
19 over >r >r new-sequence r> call r> like ; inline
21 M: sequence like drop ;
23 GENERIC: lengthen ( n seq -- )
24 GENERIC: shorten ( n seq -- )
26 M: sequence lengthen 2dup length > [ set-length ] [ 2drop ] if ;
28 M: sequence shorten 2dup length < [ set-length ] [ 2drop ] if ;
30 : empty? ( seq -- ? ) length zero? ; inline
31 : delete-all ( seq -- ) 0 swap set-length ;
33 : first ( seq -- first ) 0 swap nth ; inline
34 : second ( seq -- second ) 1 swap nth ; inline
35 : third ( seq -- third ) 2 swap nth ; inline
36 : fourth ( seq -- fourth ) 3 swap nth ; inline
38 : set-first ( first seq -- ) 0 swap set-nth ; inline
39 : set-second ( second seq -- ) 1 swap set-nth ; inline
40 : set-third ( third seq -- ) 2 swap set-nth ; inline
41 : set-fourth ( fourth seq -- ) 3 swap set-nth ; inline
43 : push ( elt seq -- ) [ length ] [ set-nth ] bi ;
45 : bounds-check? ( n seq -- ? )
46 length 1- 0 swap between? ; inline
48 ERROR: bounds-error index seq ;
50 : bounds-check ( n seq -- n seq )
51 2dup bounds-check? [ bounds-error ] unless ; inline
53 MIXIN: immutable-sequence
55 ERROR: immutable seq ;
57 M: immutable-sequence set-nth immutable ;
59 INSTANCE: immutable-sequence sequence
63 : array-nth ( n array -- elt )
64 swap 2 fixnum+fast slot ; inline
66 : set-array-nth ( elt n array -- )
67 swap 2 fixnum+fast set-slot ; inline
69 : dispatch ( n array -- ) array-nth (call) ;
71 GENERIC: resize ( n seq -- newseq ) flushable
73 ! Unsafe sequence protocol for inner loops
74 GENERIC: nth-unsafe ( n seq -- elt ) flushable
75 GENERIC: set-nth-unsafe ( elt n seq -- )
77 M: sequence nth bounds-check nth-unsafe ;
78 M: sequence set-nth bounds-check set-nth-unsafe ;
80 M: sequence nth-unsafe nth ;
81 M: sequence set-nth-unsafe set-nth ;
83 ! The f object supports the sequence protocol trivially
86 M: f like drop dup empty? [ drop f ] when ;
88 INSTANCE: f immutable-sequence
90 ! Integers support the sequence protocol
92 M: integer nth-unsafe drop ;
94 INSTANCE: integer immutable-sequence
97 [ 0 swap nth-unsafe 1 ] [ nth-unsafe ] bi ; inline
100 [ first2-unsafe 2 ] [ nth-unsafe ] bi ; inline
103 [ first3-unsafe 3 ] [ nth-unsafe ] bi ; inline
105 : exchange-unsafe ( m n seq -- )
106 [ tuck nth-unsafe >r nth-unsafe r> ] 3keep tuck
107 >r >r set-nth-unsafe r> r> set-nth-unsafe ; inline
109 : (head) ( seq n -- from to seq ) 0 spin ; inline
111 : (tail) ( seq n -- from to seq ) over length rot ; inline
113 : from-end >r dup length r> - ; inline
116 tuck 1 swap set-nth-unsafe
117 tuck 0 swap set-nth-unsafe ; inline
120 tuck 2 swap set-nth-unsafe
124 tuck 3 swap set-nth-unsafe
129 : 2sequence ( obj1 obj2 exemplar -- seq )
130 2 swap [ (2sequence) ] new-like ; inline
132 : 3sequence ( obj1 obj2 obj3 exemplar -- seq )
133 3 swap [ (3sequence) ] new-like ; inline
135 : 4sequence ( obj1 obj2 obj3 obj4 exemplar -- seq )
136 4 swap [ (4sequence) ] new-like ; inline
138 : first2 ( seq -- first second )
139 1 swap bounds-check nip first2-unsafe ; flushable
141 : first3 ( seq -- first second third )
142 2 swap bounds-check nip first3-unsafe ; flushable
144 : first4 ( seq -- first second third fourth )
145 3 swap bounds-check nip first4-unsafe ; flushable
147 : ?nth ( n seq -- elt/f )
148 2dup bounds-check? [ nth-unsafe ] [ 2drop f ] if ; flushable
150 MIXIN: virtual-sequence
151 GENERIC: virtual-seq ( seq -- seq' )
152 GENERIC: virtual@ ( n seq -- n' seq' )
154 M: virtual-sequence nth virtual@ nth ;
155 M: virtual-sequence set-nth virtual@ set-nth ;
156 M: virtual-sequence nth-unsafe virtual@ nth-unsafe ;
157 M: virtual-sequence set-nth-unsafe virtual@ set-nth-unsafe ;
158 M: virtual-sequence like virtual-seq like ;
159 M: virtual-sequence new-sequence virtual-seq new-sequence ;
161 INSTANCE: virtual-sequence sequence
163 ! A reversal of an underlying sequence.
164 TUPLE: reversed { seq read-only } ;
166 C: <reversed> reversed
168 M: reversed virtual-seq seq>> ;
170 M: reversed virtual@ seq>> [ length swap - 1- ] keep ;
172 M: reversed length seq>> length ;
174 INSTANCE: reversed virtual-sequence
176 ! A slice of another sequence.
182 : collapse-slice ( m n slice -- m' n' seq )
183 [ from>> ] [ seq>> ] bi >r tuck + >r + r> r> ; inline
185 ERROR: slice-error reason ;
187 : check-slice ( from to seq -- from to seq )
188 pick 0 < [ "start < 0" slice-error ] when
189 dup length pick < [ "end > sequence" slice-error ] when
190 2over > [ "start > end" slice-error ] when ; inline
192 : <slice> ( from to seq -- slice )
193 dup slice? [ collapse-slice ] when
197 M: slice virtual-seq seq>> ;
199 M: slice virtual@ [ from>> + ] [ seq>> ] bi ;
201 M: slice length [ to>> ] [ from>> ] bi - ;
203 : short ( seq n -- seq n' ) over length min ; inline
205 : head-slice ( seq n -- slice ) (head) <slice> ; inline
207 : tail-slice ( seq n -- slice ) (tail) <slice> ; inline
209 : rest-slice ( seq -- slice ) 1 tail-slice ; inline
211 : head-slice* ( seq n -- slice ) from-end head-slice ; inline
213 : tail-slice* ( seq n -- slice ) from-end tail-slice ; inline
215 : but-last-slice ( seq -- slice ) 1 head-slice* ; inline
217 INSTANCE: slice virtual-sequence
219 ! One element repeated many times
220 TUPLE: repetition { len read-only } { elt read-only } ;
222 C: <repetition> repetition
224 M: repetition length len>> ;
225 M: repetition nth-unsafe nip elt>> ;
227 INSTANCE: repetition immutable-sequence
231 : ((copy)) ( dst i src j n -- dst i src j n )
233 + swap nth-unsafe -roll [
234 + swap set-nth-unsafe
238 : (copy) ( dst i src j n -- dst )
239 dup 0 <= [ 2drop 2drop ] [ 1- ((copy)) (copy) ] if ;
242 : prepare-subseq ( from to seq -- dst i src j n )
243 [ >r swap - r> new-sequence dup 0 ] 3keep
244 -rot drop roll length ; inline
246 : check-copy ( src n dst -- )
247 over 0 < [ bounds-error ] when
248 >r swap length + r> lengthen ; inline
252 : subseq ( from to seq -- subseq )
253 [ check-slice prepare-subseq (copy) ] [ like ] bi ;
255 : head ( seq n -- headseq ) (head) subseq ;
257 : tail ( seq n -- tailseq ) (tail) subseq ;
259 : rest ( seq -- tailseq ) 1 tail ;
261 : head* ( seq n -- headseq ) from-end head ;
263 : tail* ( seq n -- tailseq ) from-end tail ;
265 : but-last ( seq -- headseq ) 1 head* ;
267 : copy ( src i dst -- )
268 pick length >r 3dup check-copy spin 0 r>
271 M: sequence clone-like
272 >r dup length r> new-sequence [ 0 swap copy ] keep ;
274 M: immutable-sequence clone-like like ;
276 : push-all ( src dest -- ) [ length ] [ copy ] bi ;
278 : ((append)) ( seq1 seq2 accum -- accum )
279 [ >r over length r> copy ]
283 : (append) ( seq1 seq2 exemplar -- newseq )
284 >r over length over length + r>
285 [ ((append)) ] new-like ; inline
287 : (3append) ( seq1 seq2 seq3 exemplar -- newseq )
288 >r pick length pick length pick length + + r> [
289 [ >r pick length pick length + r> copy ]
293 : append ( seq1 seq2 -- newseq ) over (append) ;
295 : prepend ( seq1 seq2 -- newseq ) swap append ; inline
297 : 3append ( seq1 seq2 seq3 -- newseq ) pick (3append) ;
299 : change-nth ( i seq quot -- )
300 [ >r nth r> call ] 3keep drop set-nth ; inline
302 : min-length ( seq1 seq2 -- n ) [ length ] bi@ min ; inline
304 : max-length ( seq1 seq2 -- n ) [ length ] bi@ max ; inline
308 : (each) ( seq quot -- n quot' )
309 >r dup length swap [ nth-unsafe ] curry r> compose ; inline
311 : (collect) ( quot into -- quot' )
312 [ >r keep r> set-nth-unsafe ] 2curry ; inline
314 : collect ( n quot into -- )
315 (collect) each-integer ; inline
317 : map-into ( seq quot into -- )
318 >r (each) r> collect ; inline
320 : 2nth-unsafe ( n seq1 seq2 -- elt1 elt2 )
321 >r over r> nth-unsafe >r nth-unsafe r> ; inline
323 : (2each) ( seq1 seq2 quot -- n quot' )
324 >r [ min-length ] 2keep r>
325 [ >r 2nth-unsafe r> call ] 3curry ; inline
327 : 2map-into ( seq1 seq2 quot into -- newseq )
328 >r (2each) r> collect ; inline
330 : finish-find ( i seq -- i elt )
331 over [ dupd nth-unsafe ] [ drop f ] if ; inline
333 : (find) ( seq quot quot' -- i elt )
334 pick >r >r (each) r> call r> finish-find ; inline
336 : (find-from) ( n seq quot quot' -- i elt )
337 [ 2dup bounds-check? ] 2dip
342 : (monotonic) ( seq quot -- ? )
343 [ 2dup nth-unsafe rot 1+ rot nth-unsafe ]
344 prepose curry ; inline
346 : (interleave) ( n elt between quot -- )
347 roll zero? [ nip ] [ swapd 2slip ] if call ; inline
351 : each ( seq quot -- )
352 (each) each-integer ; inline
354 : reduce ( seq identity quot -- result )
357 : map-as ( seq quot exemplar -- newseq )
358 >r over length r> [ [ map-into ] keep ] new-like ; inline
360 : map ( seq quot -- newseq )
363 : replicate ( seq quot -- newseq )
364 [ drop ] prepose map ; inline
366 : replicate-as ( seq quot exemplar -- newseq )
367 >r [ drop ] prepose r> map-as ; inline
369 : change-each ( seq quot -- )
370 over map-into ; inline
372 : accumulate ( seq identity quot -- final newseq )
373 swapd [ pick slip ] curry map ; inline
375 : 2each ( seq1 seq2 quot -- )
376 (2each) each-integer ; inline
378 : 2reverse-each ( seq1 seq2 quot -- )
379 >r [ <reversed> ] bi@ r> 2each ; inline
381 : 2reduce ( seq1 seq2 identity quot -- result )
382 >r -rot r> 2each ; inline
384 : 2map-as ( seq1 seq2 quot exemplar -- newseq )
385 >r 2over min-length r>
386 [ [ 2map-into ] keep ] new-like ; inline
388 : 2map ( seq1 seq2 quot -- newseq )
389 pick 2map-as ; inline
391 : 2change-each ( seq1 seq2 quot -- newseq )
392 pick 2map-into ; inline
394 : 2all? ( seq1 seq2 quot -- ? )
395 (2each) all-integers? ; inline
397 : find-from ( n seq quot -- i elt )
398 [ (find-integer) ] (find-from) ; inline
400 : find ( seq quot -- i elt )
401 [ find-integer ] (find) ; inline
403 : find-last-from ( n seq quot -- i elt )
404 [ nip find-last-integer ] (find-from) ; inline
406 : find-last ( seq quot -- i elt )
407 [ >r 1- r> find-last-integer ] (find) ; inline
409 : all? ( seq quot -- ? )
410 (each) all-integers? ; inline
412 : push-if ( elt quot accum -- )
413 >r keep r> rot [ push ] [ 2drop ] if ; inline
415 : pusher ( quot -- quot accum )
416 V{ } clone [ [ push-if ] 2curry ] keep ; inline
418 : filter ( seq quot -- subseq )
419 over >r pusher >r each r> r> like ; inline
421 : monotonic? ( seq quot -- ? )
422 >r dup length 1- swap r> (monotonic) all? ; inline
424 : interleave ( seq between quot -- )
425 [ (interleave) ] 2curry >r dup length swap r> 2each ; inline
427 : accumulator ( quot -- quot' vec )
428 V{ } clone [ [ push ] curry compose ] keep ; inline
430 : produce ( pred quot tail -- seq )
431 swap accumulator >r swap while r> { } like ; inline
433 : follow ( obj quot -- seq )
434 >r [ dup ] r> [ keep ] curry [ ] produce nip ; inline
436 : prepare-index ( seq quot -- seq n quot )
437 >r dup length r> ; inline
439 : each-index ( seq quot -- )
440 prepare-index 2each ; inline
442 : map-index ( seq quot -- )
443 prepare-index 2map ; inline
445 : reduce-index ( seq identity quot -- )
446 swapd each-index ; inline
448 : index ( obj seq -- n )
449 [ = ] with find drop ;
451 : index-from ( obj i seq -- n )
452 rot [ = ] curry find-from drop ;
454 : last-index ( obj seq -- n )
455 [ = ] with find-last drop ;
457 : last-index-from ( obj i seq -- n )
458 rot [ = ] curry find-last-from drop ;
460 : nths ( seq indices -- seq' )
461 swap [ nth ] curry map ;
463 : contains? ( seq quot -- ? )
464 find drop >boolean ; inline
466 : member? ( obj seq -- ? )
467 [ = ] with contains? ;
469 : memq? ( obj seq -- ? )
470 [ eq? ] with contains? ;
472 : remove ( obj seq -- newseq )
473 [ = not ] with filter ;
475 : sift ( seq -- newseq )
478 : harvest ( seq -- newseq )
479 [ empty? not ] filter ;
481 : cache-nth ( i seq quot -- elt )
485 drop swap >r over >r call dup r> r> set-nth
488 : mismatch ( seq1 seq2 -- i )
490 [ 2nth-unsafe = not ] 2curry
495 [ -rot 2nth-unsafe <=> ] [ [ length ] compare ] if* ;
497 : sequence= ( seq1 seq2 -- ? )
498 2dup [ length ] bi@ number=
499 [ mismatch not ] [ 2drop f ] if ; inline
501 : sequence-hashcode-step ( oldhash newpart -- newhash )
503 dup -2 fixnum-shift-fast swap 5 fixnum-shift-fast
504 fixnum+fast fixnum+fast
505 ] keep fixnum-bitxor ; inline
507 : sequence-hashcode ( n seq -- x )
508 0 -rot [ hashcode* sequence-hashcode-step ] with each ; inline
510 M: reversed equal? over reversed? [ sequence= ] [ 2drop f ] if ;
512 M: slice equal? over slice? [ sequence= ] [ 2drop f ] if ;
514 : move ( to from seq -- )
516 [ 3drop ] [ [ nth swap ] [ set-nth ] bi ] if ; inline
518 : (delete) ( elt store scan seq -- elt store scan seq )
521 [ nth pick = ] 2keep rot
522 [ >r >r 1+ r> r> ] unless >r 1+ r> (delete)
525 : delete ( elt seq -- ) 0 0 rot (delete) nip set-length drop ;
527 : prefix ( seq elt -- newseq )
528 over >r over length 1+ r> [
529 [ 0 swap set-nth-unsafe ] keep
533 : suffix ( seq elt -- newseq )
534 over >r over length 1+ r> [
535 [ >r over length r> set-nth-unsafe ] keep
539 : peek ( seq -- elt ) [ length 1- ] [ nth ] bi ;
541 : pop* ( seq -- ) [ length 1- ] [ shorten ] bi ;
543 : move-backward ( shift from to seq -- )
547 [ >r 2over + pick r> move >r 1+ r> ] keep
551 : move-forward ( shift from to seq -- )
555 [ >r pick >r dup dup r> + swap r> move 1- ] keep
559 : (open-slice) ( shift from to seq ? -- )
561 >r [ 1- ] bi@ r> move-forward
563 >r >r over - r> r> move-backward
566 : open-slice ( shift from seq -- )
570 pick over length + over >r >r
571 pick 0 > >r [ length ] keep r> (open-slice)
575 : delete-slice ( from to seq -- )
576 check-slice >r over >r - r> r> open-slice ;
578 : delete-nth ( n seq -- )
579 >r dup 1+ r> delete-slice ;
581 : replace-slice ( new from to seq -- )
582 [ >r >r dup pick length + r> - over r> open-slice ] keep
586 [ length 1- ] [ [ nth ] [ shorten ] 2bi ] bi ;
588 : all-equal? ( seq -- ? ) [ = ] monotonic? ;
590 : all-eq? ( seq -- ? ) [ eq? ] monotonic? ;
592 : exchange ( m n seq -- )
593 pick over bounds-check 2drop 2dup bounds-check 2drop
596 : reverse-here ( seq -- )
599 tuck - 1- rot exchange-unsafe
602 : reverse ( seq -- newseq )
604 dup [ length ] keep new-sequence
606 [ reverse-here ] keep
609 : sum-lengths ( seq -- n )
610 0 [ length + ] reduce ;
612 : concat ( seq -- newseq )
617 [ first new-resizable ] keep
618 [ [ over push-all ] each ] keep
622 : joined-length ( seq glue -- n )
623 >r dup sum-lengths swap length 1 [-] r> length * + ;
625 : join ( seq glue -- newseq )
627 2dup joined-length over new-resizable spin
628 [ dup pick push-all ] [ pick push-all ] interleave drop
631 : padding ( seq n elt quot -- newseq )
633 [ over length [-] dup zero? [ drop ] ] dip
634 [ <repetition> ] curry
635 ] dip compose if ; inline
637 : pad-left ( seq n elt -- padded )
638 [ swap dup (append) ] padding ;
640 : pad-right ( seq n elt -- padded )
643 : shorter? ( seq1 seq2 -- ? ) >r length r> length < ;
645 : head? ( seq begin -- ? )
649 tuck length head-slice sequence=
652 : tail? ( seq end -- ? )
656 tuck length tail-slice* sequence=
659 : cut-slice ( seq n -- before after )
660 [ head-slice ] [ tail-slice ] 2bi ;
662 : midpoint@ ( seq -- n ) length 2/ ; inline
664 : halves ( seq -- first second )
665 dup midpoint@ cut-slice ;
667 : binary-reduce ( seq start quot: ( elt1 elt2 -- newelt ) -- value )
668 #! We can't use case here since combinators depends on
670 pick length dup 0 3 between? [
674 [ >r drop first2 r> call ]
675 [ >r drop first3 r> bi@ ]
680 [ [ binary-reduce ] 2curry bi@ ] keep
682 ] if ; inline recursive
684 : cut ( seq n -- before after )
685 [ head ] [ tail ] 2bi ;
687 : cut* ( seq n -- before after )
688 [ head* ] [ tail* ] 2bi ;
692 : (start) ( subseq seq n -- subseq seq ? )
694 >r 3dup r> [ + swap nth-unsafe ] keep rot nth-unsafe =
699 : start* ( subseq seq n -- i )
700 pick length pick length swap - 1+
701 [ (start) ] find-from
704 : start ( subseq seq -- i ) 0 start* ; inline
706 : subseq? ( subseq seq -- ? ) start >boolean ;
708 : drop-prefix ( seq1 seq2 -- slice1 slice2 )
709 2dup mismatch [ 2dup min-length ] unless*
710 tuck tail-slice >r tail-slice r> ;
712 : unclip ( seq -- rest first )
713 [ rest ] [ first ] bi ;
715 : unclip-last ( seq -- butlast last )
716 [ but-last ] [ peek ] bi ;
718 : unclip-slice ( seq -- rest first )
719 [ rest-slice ] [ first ] bi ;
721 : unclip-last-slice ( seq -- butfirst last )
722 [ but-last-slice ] [ peek ] bi ;
724 : <flat-slice> ( seq -- slice )
725 dup slice? [ { } like ] when 0 over length rot <slice> ;
728 : left-trim ( seq quot -- newseq )
729 over >r [ not ] compose find drop r> swap
730 [ tail ] [ dup length tail ] if* ; inline
732 : right-trim ( seq quot -- newseq )
733 over >r [ not ] compose find-last drop r> swap
734 [ 1+ head ] [ 0 head ] if* ; inline
736 : trim ( seq quot -- newseq )
737 [ left-trim ] [ right-trim ] bi ; inline
739 : sum ( seq -- n ) 0 [ + ] binary-reduce ;
741 : product ( seq -- n ) 1 [ * ] binary-reduce ;
743 : infimum ( seq -- n ) dup first [ min ] reduce ;
745 : supremum ( seq -- n ) dup first [ max ] reduce ;
747 : flip ( matrix -- newmatrix )
749 dup [ length ] map infimum
750 swap [ [ nth-unsafe ] with { } map-as ] curry { } map-as
753 : sigma ( seq quot -- n ) [ + ] compose 0 swap reduce ; inline
755 : count ( seq quot -- n ) [ 1 0 ? ] compose sigma ; inline