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
32 : if-empty ( seq quot1 quot2 -- )
33 [ dup empty? ] [ [ drop ] prepose ] [ ] tri* if ; inline
35 : when-empty ( seq quot1 -- ) [ ] if-empty ; inline
37 : unless-empty ( seq quot1 -- ) [ ] swap if-empty ; inline
39 : delete-all ( seq -- ) 0 swap set-length ;
41 : first ( seq -- first ) 0 swap nth ; inline
42 : second ( seq -- second ) 1 swap nth ; inline
43 : third ( seq -- third ) 2 swap nth ; inline
44 : fourth ( seq -- fourth ) 3 swap nth ; inline
46 : set-first ( first seq -- ) 0 swap set-nth ; inline
47 : set-second ( second seq -- ) 1 swap set-nth ; inline
48 : set-third ( third seq -- ) 2 swap set-nth ; inline
49 : set-fourth ( fourth seq -- ) 3 swap set-nth ; inline
51 : push ( elt seq -- ) [ length ] [ set-nth ] bi ;
53 : bounds-check? ( n seq -- ? )
54 length 1- 0 swap between? ; inline
56 ERROR: bounds-error index seq ;
58 : bounds-check ( n seq -- n seq )
59 2dup bounds-check? [ bounds-error ] unless ; inline
61 MIXIN: immutable-sequence
63 ERROR: immutable seq ;
65 M: immutable-sequence set-nth immutable ;
67 INSTANCE: immutable-sequence sequence
71 : array-nth ( n array -- elt )
72 swap 2 fixnum+fast slot ; inline
74 : set-array-nth ( elt n array -- )
75 swap 2 fixnum+fast set-slot ; inline
77 : dispatch ( n array -- ) array-nth (call) ;
79 GENERIC: resize ( n seq -- newseq ) flushable
81 ! Unsafe sequence protocol for inner loops
82 GENERIC: nth-unsafe ( n seq -- elt ) flushable
83 GENERIC: set-nth-unsafe ( elt n seq -- )
85 M: sequence nth bounds-check nth-unsafe ;
86 M: sequence set-nth bounds-check set-nth-unsafe ;
88 M: sequence nth-unsafe nth ;
89 M: sequence set-nth-unsafe set-nth ;
91 ! The f object supports the sequence protocol trivially
94 M: f like drop dup empty? [ drop f ] when ;
96 INSTANCE: f immutable-sequence
98 ! Integers support the sequence protocol
100 M: integer nth-unsafe drop ;
102 INSTANCE: integer immutable-sequence
105 [ 0 swap nth-unsafe 1 ] [ nth-unsafe ] bi ; inline
108 [ first2-unsafe 2 ] [ nth-unsafe ] bi ; inline
111 [ first3-unsafe 3 ] [ nth-unsafe ] bi ; inline
113 : exchange-unsafe ( m n seq -- )
114 [ tuck nth-unsafe >r nth-unsafe r> ] 3keep tuck
115 >r >r set-nth-unsafe r> r> set-nth-unsafe ; inline
117 : (head) ( seq n -- from to seq ) 0 spin ; inline
119 : (tail) ( seq n -- from to seq ) over length rot ; inline
121 : from-end >r dup length r> - ; inline
124 tuck 1 swap set-nth-unsafe
125 tuck 0 swap set-nth-unsafe ; inline
128 tuck 2 swap set-nth-unsafe
132 tuck 3 swap set-nth-unsafe
137 : 2sequence ( obj1 obj2 exemplar -- seq )
138 2 swap [ (2sequence) ] new-like ; inline
140 : 3sequence ( obj1 obj2 obj3 exemplar -- seq )
141 3 swap [ (3sequence) ] new-like ; inline
143 : 4sequence ( obj1 obj2 obj3 obj4 exemplar -- seq )
144 4 swap [ (4sequence) ] new-like ; inline
146 : first2 ( seq -- first second )
147 1 swap bounds-check nip first2-unsafe ; flushable
149 : first3 ( seq -- first second third )
150 2 swap bounds-check nip first3-unsafe ; flushable
152 : first4 ( seq -- first second third fourth )
153 3 swap bounds-check nip first4-unsafe ; flushable
155 : ?nth ( n seq -- elt/f )
156 2dup bounds-check? [ nth-unsafe ] [ 2drop f ] if ; flushable
158 MIXIN: virtual-sequence
159 GENERIC: virtual-seq ( seq -- seq' )
160 GENERIC: virtual@ ( n seq -- n' seq' )
162 M: virtual-sequence nth virtual@ nth ;
163 M: virtual-sequence set-nth virtual@ set-nth ;
164 M: virtual-sequence nth-unsafe virtual@ nth-unsafe ;
165 M: virtual-sequence set-nth-unsafe virtual@ set-nth-unsafe ;
166 M: virtual-sequence like virtual-seq like ;
167 M: virtual-sequence new-sequence virtual-seq new-sequence ;
169 INSTANCE: virtual-sequence sequence
171 ! A reversal of an underlying sequence.
172 TUPLE: reversed { seq read-only } ;
174 C: <reversed> reversed
176 M: reversed virtual-seq seq>> ;
178 M: reversed virtual@ seq>> [ length swap - 1- ] keep ;
180 M: reversed length seq>> length ;
182 INSTANCE: reversed virtual-sequence
184 ! A slice of another sequence.
190 : collapse-slice ( m n slice -- m' n' seq )
191 [ from>> ] [ seq>> ] bi >r tuck + >r + r> r> ; inline
193 ERROR: slice-error reason ;
195 : check-slice ( from to seq -- from to seq )
196 pick 0 < [ "start < 0" slice-error ] when
197 dup length pick < [ "end > sequence" slice-error ] when
198 2over > [ "start > end" slice-error ] when ; inline
200 : <slice> ( from to seq -- slice )
201 dup slice? [ collapse-slice ] when
205 M: slice virtual-seq seq>> ;
207 M: slice virtual@ [ from>> + ] [ seq>> ] bi ;
209 M: slice length [ to>> ] [ from>> ] bi - ;
211 : short ( seq n -- seq n' ) over length min ; inline
213 : head-slice ( seq n -- slice ) (head) <slice> ; inline
215 : tail-slice ( seq n -- slice ) (tail) <slice> ; inline
217 : rest-slice ( seq -- slice ) 1 tail-slice ; inline
219 : head-slice* ( seq n -- slice ) from-end head-slice ; inline
221 : tail-slice* ( seq n -- slice ) from-end tail-slice ; inline
223 : but-last-slice ( seq -- slice ) 1 head-slice* ; inline
225 INSTANCE: slice virtual-sequence
227 ! One element repeated many times
228 TUPLE: repetition { len read-only } { elt read-only } ;
230 C: <repetition> repetition
232 M: repetition length len>> ;
233 M: repetition nth-unsafe nip elt>> ;
235 INSTANCE: repetition immutable-sequence
239 : ((copy)) ( dst i src j n -- dst i src j n )
241 + swap nth-unsafe -roll [
242 + swap set-nth-unsafe
246 : (copy) ( dst i src j n -- dst )
247 dup 0 <= [ 2drop 2drop ] [ 1- ((copy)) (copy) ] if ;
250 : prepare-subseq ( from to seq -- dst i src j n )
251 [ >r swap - r> new-sequence dup 0 ] 3keep
252 -rot drop roll length ; inline
254 : check-copy ( src n dst -- )
255 over 0 < [ bounds-error ] when
256 >r swap length + r> lengthen ; inline
260 : subseq ( from to seq -- subseq )
261 [ check-slice prepare-subseq (copy) ] [ like ] bi ;
263 : head ( seq n -- headseq ) (head) subseq ;
265 : tail ( seq n -- tailseq ) (tail) subseq ;
267 : rest ( seq -- tailseq ) 1 tail ;
269 : head* ( seq n -- headseq ) from-end head ;
271 : tail* ( seq n -- tailseq ) from-end tail ;
273 : but-last ( seq -- headseq ) 1 head* ;
275 : copy ( src i dst -- )
276 pick length >r 3dup check-copy spin 0 r>
279 M: sequence clone-like
280 >r dup length r> new-sequence [ 0 swap copy ] keep ;
282 M: immutable-sequence clone-like like ;
284 : push-all ( src dest -- ) [ length ] [ copy ] bi ;
286 : ((append)) ( seq1 seq2 accum -- accum )
287 [ >r over length r> copy ]
291 : (append) ( seq1 seq2 exemplar -- newseq )
292 >r over length over length + r>
293 [ ((append)) ] new-like ; inline
295 : (3append) ( seq1 seq2 seq3 exemplar -- newseq )
296 >r pick length pick length pick length + + r> [
297 [ >r pick length pick length + r> copy ]
301 : append ( seq1 seq2 -- newseq ) over (append) ;
303 : prepend ( seq1 seq2 -- newseq ) swap append ; inline
305 : 3append ( seq1 seq2 seq3 -- newseq ) pick (3append) ;
307 : change-nth ( i seq quot -- )
308 [ >r nth r> call ] 3keep drop set-nth ; inline
310 : min-length ( seq1 seq2 -- n ) [ length ] bi@ min ; inline
312 : max-length ( seq1 seq2 -- n ) [ length ] bi@ max ; inline
316 : (each) ( seq quot -- n quot' )
317 >r dup length swap [ nth-unsafe ] curry r> compose ; inline
319 : (collect) ( quot into -- quot' )
320 [ >r keep r> set-nth-unsafe ] 2curry ; inline
322 : collect ( n quot into -- )
323 (collect) each-integer ; inline
325 : map-into ( seq quot into -- )
326 >r (each) r> collect ; inline
328 : 2nth-unsafe ( n seq1 seq2 -- elt1 elt2 )
329 >r over r> nth-unsafe >r nth-unsafe r> ; inline
331 : (2each) ( seq1 seq2 quot -- n quot' )
332 >r [ min-length ] 2keep r>
333 [ >r 2nth-unsafe r> call ] 3curry ; inline
335 : 2map-into ( seq1 seq2 quot into -- newseq )
336 >r (2each) r> collect ; inline
338 : finish-find ( i seq -- i elt )
339 over [ dupd nth-unsafe ] [ drop f ] if ; inline
341 : (find) ( seq quot quot' -- i elt )
342 pick >r >r (each) r> call r> finish-find ; inline
344 : (find-from) ( n seq quot quot' -- i elt )
345 [ 2dup bounds-check? ] 2dip
350 : (monotonic) ( seq quot -- ? )
351 [ 2dup nth-unsafe rot 1+ rot nth-unsafe ]
352 prepose curry ; inline
354 : (interleave) ( n elt between quot -- )
355 roll zero? [ nip ] [ swapd 2slip ] if call ; inline
359 : each ( seq quot -- )
360 (each) each-integer ; inline
362 : reduce ( seq identity quot -- result )
365 : map-as ( seq quot exemplar -- newseq )
366 >r over length r> [ [ map-into ] keep ] new-like ; inline
368 : map ( seq quot -- newseq )
371 : replicate ( seq quot -- newseq )
372 [ drop ] prepose map ; inline
374 : replicate-as ( seq quot exemplar -- newseq )
375 >r [ drop ] prepose r> map-as ; inline
377 : change-each ( seq quot -- )
378 over map-into ; inline
380 : accumulate ( seq identity quot -- final newseq )
381 swapd [ pick slip ] curry map ; inline
383 : 2each ( seq1 seq2 quot -- )
384 (2each) each-integer ; inline
386 : 2reverse-each ( seq1 seq2 quot -- )
387 >r [ <reversed> ] bi@ r> 2each ; inline
389 : 2reduce ( seq1 seq2 identity quot -- result )
390 >r -rot r> 2each ; inline
392 : 2map-as ( seq1 seq2 quot exemplar -- newseq )
393 >r 2over min-length r>
394 [ [ 2map-into ] keep ] new-like ; inline
396 : 2map ( seq1 seq2 quot -- newseq )
397 pick 2map-as ; inline
399 : 2change-each ( seq1 seq2 quot -- newseq )
400 pick 2map-into ; inline
402 : 2all? ( seq1 seq2 quot -- ? )
403 (2each) all-integers? ; inline
405 : find-from ( n seq quot -- i elt )
406 [ (find-integer) ] (find-from) ; inline
408 : find ( seq quot -- i elt )
409 [ find-integer ] (find) ; inline
411 : find-last-from ( n seq quot -- i elt )
412 [ nip find-last-integer ] (find-from) ; inline
414 : find-last ( seq quot -- i elt )
415 [ >r 1- r> find-last-integer ] (find) ; inline
417 : all? ( seq quot -- ? )
418 (each) all-integers? ; inline
420 : push-if ( elt quot accum -- )
421 >r keep r> rot [ push ] [ 2drop ] if ; inline
423 : pusher ( quot -- quot accum )
424 V{ } clone [ [ push-if ] 2curry ] keep ; inline
426 : filter ( seq quot -- subseq )
427 over >r pusher >r each r> r> like ; inline
429 : push-either ( elt quot accum1 accum2 -- )
430 >r >r keep swap r> r> ? push ; inline
432 : 2pusher ( quot -- quot accum1 accum2 )
433 V{ } clone V{ } clone [ [ push-either ] 3curry ] 2keep ; inline
435 : partition ( seq quot -- trueseq falseseq )
436 over >r 2pusher >r >r each r> r> r> tuck [ like ] 2bi@ ; inline
438 : monotonic? ( seq quot -- ? )
439 >r dup length 1- swap r> (monotonic) all? ; inline
441 : interleave ( seq between quot -- )
442 [ (interleave) ] 2curry >r dup length swap r> 2each ; inline
444 : accumulator ( quot -- quot' vec )
445 V{ } clone [ [ push ] curry compose ] keep ; inline
447 : produce ( pred quot tail -- seq )
448 swap accumulator >r swap while r> { } like ; inline
450 : follow ( obj quot -- seq )
451 >r [ dup ] r> [ keep ] curry [ ] produce nip ; inline
453 : prepare-index ( seq quot -- seq n quot )
454 >r dup length r> ; inline
456 : each-index ( seq quot -- )
457 prepare-index 2each ; inline
459 : map-index ( seq quot -- )
460 prepare-index 2map ; inline
462 : reduce-index ( seq identity quot -- )
463 swapd each-index ; inline
465 : index ( obj seq -- n )
466 [ = ] with find drop ;
468 : index-from ( obj i seq -- n )
469 rot [ = ] curry find-from drop ;
471 : last-index ( obj seq -- n )
472 [ = ] with find-last drop ;
474 : last-index-from ( obj i seq -- n )
475 rot [ = ] curry find-last-from drop ;
477 : nths ( seq indices -- seq' )
478 swap [ nth ] curry map ;
480 : contains? ( seq quot -- ? )
481 find drop >boolean ; inline
483 : member? ( obj seq -- ? )
484 [ = ] with contains? ;
486 : memq? ( obj seq -- ? )
487 [ eq? ] with contains? ;
489 : remove ( obj seq -- newseq )
490 [ = not ] with filter ;
492 : sift ( seq -- newseq )
495 : harvest ( seq -- newseq )
496 [ empty? not ] filter ;
498 : cache-nth ( i seq quot -- elt )
502 drop swap >r over >r call dup r> r> set-nth
505 : mismatch ( seq1 seq2 -- i )
507 [ 2nth-unsafe = not ] 2curry
512 [ -rot 2nth-unsafe <=> ] [ [ length ] compare ] if* ;
514 : sequence= ( seq1 seq2 -- ? )
515 2dup [ length ] bi@ number=
516 [ mismatch not ] [ 2drop f ] if ; inline
518 : sequence-hashcode-step ( oldhash newpart -- newhash )
520 dup -2 fixnum-shift-fast swap 5 fixnum-shift-fast
521 fixnum+fast fixnum+fast
522 ] keep fixnum-bitxor ; inline
524 : sequence-hashcode ( n seq -- x )
525 0 -rot [ hashcode* sequence-hashcode-step ] with each ; inline
527 M: reversed equal? over reversed? [ sequence= ] [ 2drop f ] if ;
529 M: slice equal? over slice? [ sequence= ] [ 2drop f ] if ;
531 : move ( to from seq -- )
533 [ 3drop ] [ [ nth swap ] [ set-nth ] bi ] if ; inline
535 : (delete) ( elt store scan seq -- elt store scan seq )
538 [ nth pick = ] 2keep rot
539 [ >r >r 1+ r> r> ] unless >r 1+ r> (delete)
542 : delete ( elt seq -- ) 0 0 rot (delete) nip set-length drop ;
544 : prefix ( seq elt -- newseq )
545 over >r over length 1+ r> [
546 [ 0 swap set-nth-unsafe ] keep
550 : suffix ( seq elt -- newseq )
551 over >r over length 1+ r> [
552 [ >r over length r> set-nth-unsafe ] keep
556 : peek ( seq -- elt ) [ length 1- ] [ nth ] bi ;
558 : pop* ( seq -- ) [ length 1- ] [ shorten ] bi ;
560 : move-backward ( shift from to seq -- )
564 [ >r 2over + pick r> move >r 1+ r> ] keep
568 : move-forward ( shift from to seq -- )
572 [ >r pick >r dup dup r> + swap r> move 1- ] keep
576 : (open-slice) ( shift from to seq ? -- )
578 >r [ 1- ] bi@ r> move-forward
580 >r >r over - r> r> move-backward
583 : open-slice ( shift from seq -- )
587 pick over length + over >r >r
588 pick 0 > >r [ length ] keep r> (open-slice)
592 : delete-slice ( from to seq -- )
593 check-slice >r over >r - r> r> open-slice ;
595 : delete-nth ( n seq -- )
596 >r dup 1+ r> delete-slice ;
598 : replace-slice ( new from to seq -- )
599 [ >r >r dup pick length + r> - over r> open-slice ] keep
602 : remove-nth ( n seq -- seq' )
603 [ swap head-slice ] [ swap 1+ tail-slice ] 2bi append ;
606 [ length 1- ] [ [ nth ] [ shorten ] 2bi ] bi ;
608 : all-equal? ( seq -- ? ) [ = ] monotonic? ;
610 : all-eq? ( seq -- ? ) [ eq? ] monotonic? ;
612 : exchange ( m n seq -- )
613 pick over bounds-check 2drop 2dup bounds-check 2drop
616 : reverse-here ( seq -- )
619 tuck - 1- rot exchange-unsafe
622 : reverse ( seq -- newseq )
624 dup [ length ] keep new-sequence
626 [ reverse-here ] keep
629 : sum-lengths ( seq -- n )
630 0 [ length + ] reduce ;
632 : concat ( seq -- newseq )
637 [ first new-resizable ] keep
638 [ [ over push-all ] each ] keep
642 : joined-length ( seq glue -- n )
643 >r dup sum-lengths swap length 1 [-] r> length * + ;
645 : join ( seq glue -- newseq )
647 2dup joined-length over new-resizable spin
648 [ dup pick push-all ] [ pick push-all ] interleave drop
651 : padding ( seq n elt quot -- newseq )
653 [ over length [-] dup zero? [ drop ] ] dip
654 [ <repetition> ] curry
655 ] dip compose if ; inline
657 : pad-left ( seq n elt -- padded )
658 [ swap dup (append) ] padding ;
660 : pad-right ( seq n elt -- padded )
663 : shorter? ( seq1 seq2 -- ? ) >r length r> length < ;
665 : head? ( seq begin -- ? )
669 tuck length head-slice sequence=
672 : tail? ( seq end -- ? )
676 tuck length tail-slice* sequence=
679 : cut-slice ( seq n -- before after )
680 [ head-slice ] [ tail-slice ] 2bi ;
682 : insert-nth ( elt n seq -- seq' )
683 swap cut-slice [ swap suffix ] dip append ;
685 : midpoint@ ( seq -- n ) length 2/ ; inline
687 : halves ( seq -- first second )
688 dup midpoint@ cut-slice ;
690 : binary-reduce ( seq start quot: ( elt1 elt2 -- newelt ) -- value )
691 #! We can't use case here since combinators depends on
693 pick length dup 0 3 between? [
697 [ >r drop first2 r> call ]
698 [ >r drop first3 r> bi@ ]
703 [ [ binary-reduce ] 2curry bi@ ] keep
705 ] if ; inline recursive
707 : cut ( seq n -- before after )
708 [ head ] [ tail ] 2bi ;
710 : cut* ( seq n -- before after )
711 [ head* ] [ tail* ] 2bi ;
715 : (start) ( subseq seq n -- subseq seq ? )
717 >r 3dup r> [ + swap nth-unsafe ] keep rot nth-unsafe =
722 : start* ( subseq seq n -- i )
723 pick length pick length swap - 1+
724 [ (start) ] find-from
727 : start ( subseq seq -- i ) 0 start* ; inline
729 : subseq? ( subseq seq -- ? ) start >boolean ;
731 : drop-prefix ( seq1 seq2 -- slice1 slice2 )
732 2dup mismatch [ 2dup min-length ] unless*
733 tuck tail-slice >r tail-slice r> ;
735 : unclip ( seq -- rest first )
736 [ rest ] [ first ] bi ;
738 : unclip-last ( seq -- butlast last )
739 [ but-last ] [ peek ] bi ;
741 : unclip-slice ( seq -- rest first )
742 [ rest-slice ] [ first ] bi ;
744 : unclip-last-slice ( seq -- butfirst last )
745 [ but-last-slice ] [ peek ] bi ;
747 : <flat-slice> ( seq -- slice )
748 dup slice? [ { } like ] when 0 over length rot <slice> ;
751 : trim-left-slice ( seq quot -- slice )
752 over >r [ not ] compose find drop r> swap
753 [ tail-slice ] [ dup length tail-slice ] if* ; inline
755 : trim-left ( seq quot -- newseq )
756 over [ trim-left-slice ] dip like ; inline
758 : trim-right-slice ( seq quot -- slice )
759 over >r [ not ] compose find-last drop r> swap
760 [ 1+ head-slice ] [ 0 head-slice ] if* ; inline
762 : trim-right ( seq quot -- newseq )
763 over [ trim-right-slice ] dip like ; inline
765 : trim-slice ( seq quot -- slice )
766 [ trim-left-slice ] [ trim-right-slice ] bi ;
768 : trim ( seq quot -- newseq )
769 over [ trim-slice ] dip like ; inline
771 : sum ( seq -- n ) 0 [ + ] binary-reduce ;
773 : product ( seq -- n ) 1 [ * ] binary-reduce ;
775 : infimum ( seq -- n ) dup first [ min ] reduce ;
777 : supremum ( seq -- n ) dup first [ max ] reduce ;
779 : flip ( matrix -- newmatrix )
781 dup [ length ] map infimum
782 swap [ [ nth-unsafe ] with { } map-as ] curry { } map-as
785 : sigma ( seq quot -- n ) [ + ] compose 0 swap reduce ; inline
787 : count ( seq quot -- n ) [ 1 0 ? ] compose sigma ; inline