1 ! Copyright (C) 2005, 2009 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 [ [ new-sequence ] dip call ] dip 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 0 = ; inline
32 : if-empty ( seq quot1 quot2 -- )
33 [ dup empty? ] [ [ drop ] prepose ] [ ] tri* if ; inline
35 : when-empty ( seq quot -- ) [ ] if-empty ; inline
37 : unless-empty ( seq quot -- ) [ ] 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 dupd length < [ 0 >= ] [ drop f ] if ; 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 : change-nth-unsafe ( i seq quot -- )
92 [ [ nth-unsafe ] dip call ] 3keep drop set-nth-unsafe ; inline
94 ! The f object supports the sequence protocol trivially
97 M: f like drop [ f ] when-empty ;
99 INSTANCE: f immutable-sequence
101 ! Integers support the sequence protocol
103 M: integer nth-unsafe drop ;
105 INSTANCE: integer immutable-sequence
109 ! In the future, this will replace integer sequences
110 TUPLE: iota { n integer read-only } ;
112 : iota ( n -- iota ) \ iota boa ; inline
117 M: iota nth-unsafe drop ;
119 INSTANCE: iota immutable-sequence
121 : first-unsafe ( seq -- first )
122 0 swap nth-unsafe ; inline
124 : first2-unsafe ( seq -- first second )
125 [ first-unsafe ] [ 1 swap nth-unsafe ] bi ; inline
127 : first3-unsafe ( seq -- first second third )
128 [ first2-unsafe ] [ 2 swap nth-unsafe ] bi ; inline
130 : first4-unsafe ( seq -- first second third fourth )
131 [ first3-unsafe ] [ 3 swap nth-unsafe ] bi ; inline
133 : exchange-unsafe ( m n seq -- )
134 [ [ nth-unsafe ] curry bi@ ]
135 [ [ set-nth-unsafe ] curry bi@ ] 3bi ; inline
137 : (head) ( seq n -- from to seq ) [ 0 ] 2dip swap ; inline
139 : (tail) ( seq n -- from to seq ) swap [ length ] keep ; inline
141 : from-end ( seq n -- seq n' ) [ dup length ] dip - ; inline
143 : (1sequence) ( obj seq -- seq )
144 [ 0 swap set-nth-unsafe ] keep ; inline
146 : (2sequence) ( obj1 obj2 seq -- seq )
147 [ 1 swap set-nth-unsafe ] keep
150 : (3sequence) ( obj1 obj2 obj3 seq -- seq )
151 [ 2 swap set-nth-unsafe ] keep
154 : (4sequence) ( obj1 obj2 obj3 obj4 seq -- seq )
155 [ 3 swap set-nth-unsafe ] keep
160 : 1sequence ( obj exemplar -- seq )
161 1 swap [ (1sequence) ] new-like ; inline
163 : 2sequence ( obj1 obj2 exemplar -- seq )
164 2 swap [ (2sequence) ] new-like ; inline
166 : 3sequence ( obj1 obj2 obj3 exemplar -- seq )
167 3 swap [ (3sequence) ] new-like ; inline
169 : 4sequence ( obj1 obj2 obj3 obj4 exemplar -- seq )
170 4 swap [ (4sequence) ] new-like ; inline
172 : first2 ( seq -- first second )
173 1 swap bounds-check nip first2-unsafe ; flushable
175 : first3 ( seq -- first second third )
176 2 swap bounds-check nip first3-unsafe ; flushable
178 : first4 ( seq -- first second third fourth )
179 3 swap bounds-check nip first4-unsafe ; flushable
181 : ?nth ( n seq -- elt/f )
182 2dup bounds-check? [ nth-unsafe ] [ 2drop f ] if ; inline
184 MIXIN: virtual-sequence
185 GENERIC: virtual-seq ( seq -- seq' )
186 GENERIC: virtual@ ( n seq -- n' seq' )
188 M: virtual-sequence nth virtual@ nth ;
189 M: virtual-sequence set-nth virtual@ set-nth ;
190 M: virtual-sequence nth-unsafe virtual@ nth-unsafe ;
191 M: virtual-sequence set-nth-unsafe virtual@ set-nth-unsafe ;
192 M: virtual-sequence like virtual-seq like ;
193 M: virtual-sequence new-sequence virtual-seq new-sequence ;
195 INSTANCE: virtual-sequence sequence
197 ! A reversal of an underlying sequence.
198 TUPLE: reversed { seq read-only } ;
200 C: <reversed> reversed
202 M: reversed virtual-seq seq>> ;
204 M: reversed virtual@ seq>> [ length swap - 1 - ] keep ;
206 M: reversed length seq>> length ;
208 INSTANCE: reversed virtual-sequence
210 ! A slice of another sequence.
216 : collapse-slice ( m n slice -- m' n' seq )
217 [ from>> ] [ seq>> ] bi [ [ + ] curry bi@ ] dip ; inline
219 TUPLE: slice-error from to seq reason ;
221 : slice-error ( from to seq ? string -- from to seq )
222 [ \ slice-error boa throw ] curry when ; inline
224 : check-slice ( from to seq -- from to seq )
226 [ 2drop 0 < "start < 0" slice-error ]
227 [ [ drop ] 2dip length > "end > sequence" slice-error ]
228 [ drop > "start > end" slice-error ]
231 : <slice> ( from to seq -- slice )
232 dup slice? [ collapse-slice ] when
236 M: slice virtual-seq seq>> ;
238 M: slice virtual@ [ from>> + ] [ seq>> ] bi ;
240 M: slice length [ to>> ] [ from>> ] bi - ;
242 : short ( seq n -- seq n' ) over length min ; inline
244 : head-slice ( seq n -- slice ) (head) <slice> ; inline
246 : tail-slice ( seq n -- slice ) (tail) <slice> ; inline
248 : rest-slice ( seq -- slice ) 1 tail-slice ; inline
250 : head-slice* ( seq n -- slice ) from-end head-slice ; inline
252 : tail-slice* ( seq n -- slice ) from-end tail-slice ; inline
254 : but-last-slice ( seq -- slice ) 1 head-slice* ; inline
256 INSTANCE: slice virtual-sequence
258 ! One element repeated many times
259 TUPLE: repetition { len read-only } { elt read-only } ;
261 C: <repetition> repetition
263 M: repetition length len>> ;
264 M: repetition nth-unsafe nip elt>> ;
266 INSTANCE: repetition immutable-sequence
270 : check-length ( n -- n )
272 dup integer? [ "length not an integer" throw ] unless ; inline
274 : ((copy)) ( dst i src j n -- dst i src j n )
276 + swap nth-unsafe -roll [
277 + swap set-nth-unsafe
281 : (copy) ( dst i src j n -- dst )
282 dup 0 <= [ 2drop 2drop ] [ 1 - ((copy)) (copy) ] if ;
285 : prepare-subseq ( from to seq -- dst i src j n )
286 #! The check-length call forces partial dispatch
287 [ [ swap - ] dip new-sequence dup 0 ] 3keep
288 -rot drop roll length check-length ; inline
290 : check-copy ( src n dst -- )
291 over 0 < [ bounds-error ] when
292 [ swap length + ] dip lengthen ; inline
296 : subseq ( from to seq -- subseq )
297 [ check-slice prepare-subseq (copy) ] keep like ;
299 : head ( seq n -- headseq ) (head) subseq ;
301 : tail ( seq n -- tailseq ) (tail) subseq ;
303 : rest ( seq -- tailseq ) 1 tail ;
305 : head* ( seq n -- headseq ) from-end head ;
307 : tail* ( seq n -- tailseq ) from-end tail ;
309 : but-last ( seq -- headseq ) 1 head* ;
311 : copy ( src i dst -- )
312 #! The check-length call forces partial dispatch
313 pick length check-length [ 3dup check-copy spin 0 ] dip
316 M: sequence clone-like
317 [ dup length ] dip new-sequence [ 0 swap copy ] keep ;
319 M: immutable-sequence clone-like like ;
321 : push-all ( src dest -- ) [ length ] [ copy ] bi ;
325 : (append) ( seq1 seq2 accum -- accum )
326 [ [ over length ] dip copy ]
332 : append-as ( seq1 seq2 exemplar -- newseq )
333 [ over length over length + ] dip
334 [ (append) ] new-like ; inline
336 : 3append-as ( seq1 seq2 seq3 exemplar -- newseq )
337 [ 3dup [ length ] tri@ + + ] dip [
338 [ [ 2over [ length ] bi@ + ] dip copy ]
342 : append ( seq1 seq2 -- newseq ) over append-as ;
344 : prepend ( seq1 seq2 -- newseq ) swap append ; inline
346 : 3append ( seq1 seq2 seq3 -- newseq ) pick 3append-as ;
348 : surround ( seq1 seq2 seq3 -- newseq ) swapd 3append ; inline
350 : glue ( seq1 seq2 seq3 -- newseq ) swap 3append ; inline
352 : change-nth ( i seq quot -- )
353 [ [ nth ] dip call ] 3keep drop set-nth ; inline
355 : min-length ( seq1 seq2 -- n ) [ length ] bi@ min ; inline
357 : max-length ( seq1 seq2 -- n ) [ length ] bi@ max ; inline
361 : ((each)) ( seq -- n quot )
362 [ length ] keep [ nth-unsafe ] curry ; inline
364 : (each) ( seq quot -- n quot' )
365 [ ((each)) ] dip compose ; inline
367 : (each-index) ( seq quot -- n quot' )
368 [ ((each)) [ keep ] curry ] dip compose ; inline
370 : (collect) ( quot into -- quot' )
371 [ [ keep ] dip set-nth-unsafe ] 2curry ; inline
373 : collect ( n quot into -- )
374 (collect) each-integer ; inline
376 : map-into ( seq quot into -- )
377 [ (each) ] dip collect ; inline
379 : 2nth-unsafe ( n seq1 seq2 -- elt1 elt2 )
380 [ nth-unsafe ] bi-curry@ bi ; inline
382 : (2each) ( seq1 seq2 quot -- n quot' )
385 [ 2nth-unsafe ] 2curry
386 ] dip compose ; inline
388 : 3nth-unsafe ( n seq1 seq2 seq3 -- elt1 elt2 elt3 )
389 [ nth-unsafe ] tri-curry@ tri ; inline
391 : (3each) ( seq1 seq2 seq3 quot -- n quot' )
393 [ [ length ] tri@ min min ]
394 [ [ 3nth-unsafe ] 3curry ] 3bi
395 ] dip compose ; inline
397 : finish-find ( i seq -- i elt )
398 over [ dupd nth-unsafe ] [ drop f ] if ; inline
400 : (find) ( seq quot quot' -- i elt )
401 pick [ [ (each) ] dip call ] dip finish-find ; inline
403 : (find-from) ( n seq quot quot' -- i elt )
404 [ 2dup bounds-check? ] 2dip
411 : each ( seq quot -- )
412 (each) each-integer ; inline
414 : reduce ( seq identity quot -- result )
417 : map-as ( seq quot exemplar -- newseq )
418 [ over length ] dip [ [ map-into ] keep ] new-like ; inline
420 : map ( seq quot -- newseq )
423 : replicate ( seq quot -- newseq )
424 [ drop ] prepose map ; inline
426 : replicate-as ( seq quot exemplar -- newseq )
427 [ [ drop ] prepose ] dip map-as ; inline
429 : change-each ( seq quot -- )
430 over map-into ; inline
432 : accumulate ( seq identity quot -- final newseq )
433 swapd [ [ call ] [ 2drop ] 3bi ] curry { } map-as ; inline
435 : 2each ( seq1 seq2 quot -- )
436 (2each) each-integer ; inline
438 : 2reverse-each ( seq1 seq2 quot -- )
439 [ [ <reversed> ] bi@ ] dip 2each ; inline
441 : 2reduce ( seq1 seq2 identity quot -- result )
442 [ -rot ] dip 2each ; inline
444 : 2map-as ( seq1 seq2 quot exemplar -- newseq )
445 [ (2each) ] dip map-as ; inline
447 : 2map ( seq1 seq2 quot -- newseq )
448 pick 2map-as ; inline
450 : 2all? ( seq1 seq2 quot -- ? )
451 (2each) all-integers? ; inline
453 : 3each ( seq1 seq2 seq3 quot -- )
454 (3each) each ; inline
456 : 3map-as ( seq1 seq2 seq3 quot exemplar -- newseq )
457 [ (3each) ] dip map-as ; inline
459 : 3map ( seq1 seq2 seq3 quot -- newseq )
460 [ pick ] dip swap 3map-as ; inline
462 : find-from ( n seq quot -- i elt )
463 [ (find-integer) ] (find-from) ; inline
465 : find ( seq quot -- i elt )
466 [ find-integer ] (find) ; inline
468 : find-last-from ( n seq quot -- i elt )
469 [ nip find-last-integer ] (find-from) ; inline
471 : find-last ( seq quot -- i elt )
472 [ [ 1 - ] dip find-last-integer ] (find) ; inline
474 : all? ( seq quot -- ? )
475 (each) all-integers? ; inline
477 : push-if ( elt quot accum -- )
478 [ keep ] dip rot [ push ] [ 2drop ] if ; inline
480 : pusher ( quot -- quot accum )
481 V{ } clone [ [ push-if ] 2curry ] keep ; inline
483 : filter ( seq quot -- subseq )
484 over [ pusher [ each ] dip ] dip like ; inline
486 : push-either ( elt quot accum1 accum2 -- )
487 [ keep swap ] 2dip ? push ; inline
489 : 2pusher ( quot -- quot accum1 accum2 )
490 V{ } clone V{ } clone [ [ push-either ] 3curry ] 2keep ; inline
492 : partition ( seq quot -- trueseq falseseq )
493 over [ 2pusher [ each ] 2dip ] dip [ like ] curry bi@ ; inline
495 : accumulator ( quot -- quot' vec )
496 V{ } clone [ [ push ] curry compose ] keep ; inline
498 : produce-as ( pred quot exemplar -- seq )
499 [ accumulator [ while ] dip ] dip like ; inline
501 : produce ( pred quot -- seq )
502 { } produce-as ; inline
504 : follow ( obj quot -- seq )
505 [ dup ] swap [ keep ] curry produce nip ; inline
507 : each-index ( seq quot -- )
508 (each-index) each-integer ; inline
510 : interleave ( seq between quot -- )
511 pick empty? [ 3drop ] [
512 [ [ drop first-unsafe ] dip call ]
513 [ [ rest-slice ] 2dip [ bi* ] 2curry each ]
517 : map-index ( seq quot -- newseq )
518 [ dup length iota ] dip 2map ; inline
520 : reduce-index ( seq identity quot -- )
521 swapd each-index ; inline
523 : index ( obj seq -- n )
524 [ = ] with find drop ;
526 : index-from ( obj i seq -- n )
527 rot [ = ] curry find-from drop ;
529 : last-index ( obj seq -- n )
530 [ = ] with find-last drop ;
532 : last-index-from ( obj i seq -- n )
533 rot [ = ] curry find-last-from drop ;
535 : (indices) ( elt i obj accum -- )
536 [ swap [ = ] dip ] dip [ push ] 2curry when ; inline
538 : indices ( obj seq -- indices )
540 [ [ (indices) ] 2curry each-index ] keep ;
542 : nths ( indices seq -- seq' )
545 : any? ( seq quot -- ? )
546 find drop >boolean ; inline
548 : member? ( elt seq -- ? )
551 : memq? ( elt seq -- ? )
554 : remove ( elt seq -- newseq )
555 [ = not ] with filter ;
557 : remq ( elt seq -- newseq )
558 [ eq? not ] with filter ;
560 : sift ( seq -- newseq )
563 : harvest ( seq -- newseq )
564 [ empty? not ] filter ;
566 : mismatch ( seq1 seq2 -- i )
567 [ min-length iota ] 2keep
568 [ 2nth-unsafe = not ] 2curry
573 [ -rot 2nth-unsafe <=> ] [ [ length ] compare ] if* ;
575 : sequence= ( seq1 seq2 -- ? )
576 2dup [ length ] bi@ =
577 [ mismatch not ] [ 2drop f ] if ; inline
579 ERROR: assert-sequence got expected ;
581 : assert-sequence= ( a b -- )
582 2dup sequence= [ 2drop ] [ assert-sequence ] if ;
584 : sequence-hashcode-step ( oldhash newpart -- newhash )
586 [ -2 fixnum-shift-fast ] [ 5 fixnum-shift-fast ] bi
587 fixnum+fast fixnum+fast
588 ] keep fixnum-bitxor ; inline
590 : sequence-hashcode ( n seq -- x )
591 [ 0 ] 2dip [ hashcode* sequence-hashcode-step ] with each ; inline
593 M: reversed equal? over reversed? [ sequence= ] [ 2drop f ] if ;
595 M: slice equal? over slice? [ sequence= ] [ 2drop f ] if ;
597 : move ( to from seq -- )
599 [ 3drop ] [ [ nth swap ] [ set-nth ] bi ] if ; inline
603 : (filter-here) ( quot: ( elt -- ? ) store scan seq -- )
606 [ nth-unsafe pick call [ 1 + ] when ] 2keep
609 ] [ nip set-length drop ] if ; inline recursive
613 : filter-here ( seq quot -- )
614 swap [ 0 0 ] dip (filter-here) ; inline
616 : delete ( elt seq -- )
617 [ = not ] with filter-here ;
619 : delq ( elt seq -- )
620 [ eq? not ] with filter-here ;
622 : prefix ( seq elt -- newseq )
623 over [ over length 1 + ] dip [
624 [ 0 swap set-nth-unsafe ] keep
628 : suffix ( seq elt -- newseq )
629 over [ over length 1 + ] dip [
630 [ [ over length ] dip set-nth-unsafe ] keep
634 : last ( seq -- elt ) [ length 1 - ] [ nth ] bi ;
636 : pop* ( seq -- ) [ length 1 - ] [ shorten ] bi ;
640 : move-backward ( shift from to seq -- )
644 [ [ 2over + pick ] dip move [ 1 + ] dip ] keep
648 : move-forward ( shift from to seq -- )
652 [ [ pick [ dup dup ] dip + swap ] dip move 1 - ] keep
656 : (open-slice) ( shift from to seq ? -- )
658 [ [ 1 - ] bi@ ] dip move-forward
660 [ over - ] 2dip move-backward
663 : open-slice ( shift from seq -- )
667 pick over length + over
668 [ pick 0 > [ [ length ] keep ] dip (open-slice) ] 2dip
674 : delete-slice ( from to seq -- )
675 check-slice [ over [ - ] dip ] dip open-slice ;
677 : delete-nth ( n seq -- )
678 [ dup 1 + ] dip delete-slice ;
680 : snip ( from to seq -- head tail )
681 [ swap head ] [ swap tail ] bi-curry bi* ; inline
683 : snip-slice ( from to seq -- head tail )
684 [ swap head-slice ] [ swap tail-slice ] bi-curry bi* ; inline
686 : replace-slice ( new from to seq -- seq' )
687 snip-slice surround ;
689 : remove-nth ( n seq -- seq' )
690 [ [ { } ] dip dup 1 + ] dip replace-slice ;
693 [ length 1 - ] [ [ nth ] [ shorten ] 2bi ] bi ;
695 : exchange ( m n seq -- )
696 [ nip bounds-check 2drop ]
697 [ bounds-check 3drop ]
701 : reverse-here ( seq -- )
702 [ length 2/ ] [ length ] [ ] tri
703 [ [ over - 1 - ] dip exchange-unsafe ] 2curry each ;
705 : reverse ( seq -- newseq )
707 dup [ length ] keep new-sequence
709 [ reverse-here ] keep
712 : sum-lengths ( seq -- n )
713 0 [ length + ] reduce ;
715 : concat-as ( seq exemplar -- newseq )
717 [ sum-lengths over new-resizable ] keep
718 [ over push-all ] each
719 ] if-empty swap like ;
721 : concat ( seq -- newseq )
722 [ { } ] [ dup first concat-as ] if-empty ;
726 : joined-length ( seq glue -- n )
727 [ [ sum-lengths ] [ length 1 [-] ] bi ] dip length * + ;
731 : join ( seq glue -- newseq )
732 dup empty? [ concat-as ] [
734 2dup joined-length over new-resizable [
735 [ [ push-all ] 2curry ] [ [ nip push-all ] 2curry ] 2bi
741 : padding ( seq n elt quot -- newseq )
743 [ over length [-] dup 0 = [ drop ] ] dip
744 [ <repetition> ] curry
745 ] dip compose if ; inline
747 : pad-head ( seq n elt -- padded )
748 [ swap dup append-as ] padding ;
750 : pad-tail ( seq n elt -- padded )
753 : shorter? ( seq1 seq2 -- ? ) [ length ] bi@ < ;
755 : head? ( seq begin -- ? )
759 [ nip ] [ length head-slice ] 2bi sequence=
762 : tail? ( seq end -- ? )
766 [ nip ] [ length tail-slice* ] 2bi sequence=
769 : cut-slice ( seq n -- before-slice after-slice )
770 [ head-slice ] [ tail-slice ] 2bi ;
772 : insert-nth ( elt n seq -- seq' )
773 swap cut-slice [ swap suffix ] dip append ;
775 : midpoint@ ( seq -- n ) length 2/ ; inline
777 : halves ( seq -- first-slice second-slice )
778 dup midpoint@ cut-slice ;
780 : binary-reduce ( seq start quot: ( elt1 elt2 -- newelt ) -- value )
781 #! We can't use case here since combinators depends on
783 pick length dup 0 3 between? [
787 [ [ drop first2 ] dip call ]
788 [ [ drop first3 ] dip bi@ ]
793 [ [ binary-reduce ] 2curry bi@ ] keep
795 ] if ; inline recursive
797 : cut ( seq n -- before after )
798 [ head ] [ tail ] 2bi ;
800 : cut* ( seq n -- before after )
801 [ head* ] [ tail* ] 2bi ;
805 : (start) ( subseq seq n -- subseq seq ? )
807 [ 3dup ] dip [ + swap nth-unsafe ] keep rot nth-unsafe =
812 : start* ( subseq seq n -- i )
813 pick length pick length swap - 1 +
814 [ (start) ] find-from
817 : start ( subseq seq -- i ) 0 start* ; inline
819 : subseq? ( subseq seq -- ? ) start >boolean ;
821 : drop-prefix ( seq1 seq2 -- slice1 slice2 )
822 2dup mismatch [ 2dup min-length ] unless*
823 [ tail-slice ] curry bi@ ;
825 : unclip ( seq -- rest first )
826 [ rest ] [ first-unsafe ] bi ;
828 : unclip-last ( seq -- butlast last )
829 [ but-last ] [ last ] bi ;
831 : unclip-slice ( seq -- rest-slice first )
832 [ rest-slice ] [ first-unsafe ] bi ; inline
834 : 2unclip-slice ( seq1 seq2 -- rest-slice1 rest-slice2 first1 first2 )
835 [ unclip-slice ] bi@ swapd ; inline
837 : map-reduce ( seq map-quot reduce-quot -- result )
838 [ [ unclip-slice ] dip [ call ] keep ] dip
839 compose reduce ; inline
841 : 2map-reduce ( seq1 seq2 map-quot reduce-quot -- result )
842 [ [ 2unclip-slice ] dip [ call ] keep ] dip
843 compose 2reduce ; inline
847 : (map-find) ( seq quot find-quot -- result elt )
848 [ [ f ] 2dip [ [ nip ] dip call dup ] curry ] dip call
849 [ [ drop f ] unless ] dip ; inline
853 : map-find ( seq quot -- result elt )
854 [ find ] (map-find) ; inline
856 : map-find-last ( seq quot -- result elt )
857 [ find-last ] (map-find) ; inline
859 : unclip-last-slice ( seq -- butlast-slice last )
860 [ but-last-slice ] [ last ] bi ; inline
862 : <flat-slice> ( seq -- slice )
863 dup slice? [ { } like ] when
864 [ drop 0 ] [ length ] [ ] tri <slice> ;
869 : (trim-head) ( seq quot -- seq n )
870 over [ [ not ] compose find drop ] dip
871 [ length or ] keep swap ; inline
873 : (trim-tail) ( seq quot -- seq n )
874 over [ [ not ] compose find-last drop ?1+ ] dip
879 : trim-head-slice ( seq quot -- slice )
880 (trim-head) tail-slice ; inline
882 : trim-head ( seq quot -- newseq )
883 (trim-head) tail ; inline
885 : trim-tail-slice ( seq quot -- slice )
886 (trim-tail) head-slice ; inline
888 : trim-tail ( seq quot -- newseq )
889 (trim-tail) head ; inline
891 : trim-slice ( seq quot -- slice )
892 [ trim-head-slice ] [ trim-tail-slice ] bi ; inline
894 : trim ( seq quot -- newseq )
895 [ trim-slice ] [ drop ] 2bi like ; inline
897 : sum ( seq -- n ) 0 [ + ] binary-reduce ;
899 : product ( seq -- n ) 1 [ * ] binary-reduce ;
901 : infimum ( seq -- n ) [ ] [ min ] map-reduce ;
903 : supremum ( seq -- n ) [ ] [ max ] map-reduce ;
905 : sigma ( seq quot -- n )
906 [ 0 ] 2dip [ dip + ] curry [ swap ] prepose each ; inline
908 : count ( seq quot -- n ) [ 1 0 ? ] compose sigma ; inline
910 ! We hand-optimize flip to such a degree because type hints
911 ! cannot express that an array is an array of arrays yet, and
912 ! this word happens to be performance-critical since the compiler
913 ! itself uses it. Optimizing it like this reduced compile time.
916 : generic-flip ( matrix -- newmatrix )
917 [ dup first length [ length min ] reduce ] keep
918 [ [ nth-unsafe ] with { } map-as ] curry { } map-as ; inline
922 : array-length ( array -- len )
923 { array } declare length>> ; inline
925 : array-flip ( matrix -- newmatrix )
927 [ dup first array-length [ array-length min ] reduce ] keep
928 [ [ array-nth ] with { } map-as ] curry { } map-as ;
932 : flip ( matrix -- newmatrix )
936 [ array-flip ] [ generic-flip ] if
937 ] [ generic-flip ] if