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
34 : (if-empty) ( seq quot1 quot2 quot3 -- )
35 [ [ drop ] prepose ] [ ] tri* if ; inline
39 : if-empty ( seq quot1 quot2 -- )
40 [ dup empty? ] (if-empty) ; inline
42 : when-empty ( seq quot -- ) [ ] if-empty ; inline
44 : unless-empty ( seq quot -- ) [ ] swap if-empty ; inline
46 : if-zero ( n quot1 quot2 -- )
47 [ dup zero? ] (if-empty) ; inline
49 : when-zero ( n quot -- ) [ ] if-zero ; inline
51 : unless-zero ( n quot -- ) [ ] swap if-zero ; inline
53 : delete-all ( seq -- ) 0 swap set-length ;
55 : first ( seq -- first ) 0 swap nth ; inline
56 : second ( seq -- second ) 1 swap nth ; inline
57 : third ( seq -- third ) 2 swap nth ; inline
58 : fourth ( seq -- fourth ) 3 swap nth ; inline
60 : set-first ( first seq -- ) 0 swap set-nth ; inline
61 : set-second ( second seq -- ) 1 swap set-nth ; inline
62 : set-third ( third seq -- ) 2 swap set-nth ; inline
63 : set-fourth ( fourth seq -- ) 3 swap set-nth ; inline
65 : push ( elt seq -- ) [ length ] [ set-nth ] bi ;
67 : bounds-check? ( n seq -- ? )
68 dupd length < [ 0 >= ] [ drop f ] if ; inline
70 ERROR: bounds-error index seq ;
72 : bounds-check ( n seq -- n seq )
73 2dup bounds-check? [ bounds-error ] unless ; inline
75 MIXIN: immutable-sequence
77 ERROR: immutable seq ;
79 M: immutable-sequence set-nth immutable ;
81 INSTANCE: immutable-sequence sequence
85 : array-nth ( n array -- elt )
86 swap 2 fixnum+fast slot ; inline
88 : set-array-nth ( elt n array -- )
89 swap 2 fixnum+fast set-slot ; inline
91 : dispatch ( n array -- ) array-nth call ;
93 GENERIC: resize ( n seq -- newseq ) flushable
95 ! Unsafe sequence protocol for inner loops
96 GENERIC: nth-unsafe ( n seq -- elt ) flushable
97 GENERIC: set-nth-unsafe ( elt n seq -- )
99 M: sequence nth bounds-check nth-unsafe ;
100 M: sequence set-nth bounds-check set-nth-unsafe ;
102 M: sequence nth-unsafe nth ;
103 M: sequence set-nth-unsafe set-nth ;
105 : change-nth-unsafe ( i seq quot -- )
106 [ [ nth-unsafe ] dip call ] 3keep drop set-nth-unsafe ; inline
108 ! The f object supports the sequence protocol trivially
110 M: f nth-unsafe nip ;
111 M: f like drop [ f ] when-empty ;
113 INSTANCE: f immutable-sequence
115 ! Integers support the sequence protocol
117 M: integer nth-unsafe drop ;
119 INSTANCE: integer immutable-sequence
123 ! In the future, this will replace integer sequences
124 TUPLE: iota { n integer read-only } ;
126 : iota ( n -- iota ) \ iota boa ; inline
131 M: iota nth-unsafe drop ;
133 INSTANCE: iota immutable-sequence
135 : first-unsafe ( seq -- first )
136 0 swap nth-unsafe ; inline
138 : first2-unsafe ( seq -- first second )
139 [ first-unsafe ] [ 1 swap nth-unsafe ] bi ; inline
141 : first3-unsafe ( seq -- first second third )
142 [ first2-unsafe ] [ 2 swap nth-unsafe ] bi ; inline
144 : first4-unsafe ( seq -- first second third fourth )
145 [ first3-unsafe ] [ 3 swap nth-unsafe ] bi ; inline
147 : exchange-unsafe ( m n seq -- )
148 [ [ nth-unsafe ] curry bi@ ]
149 [ [ set-nth-unsafe ] curry bi@ ] 3bi ; inline
151 : (head) ( seq n -- from to seq ) [ 0 ] 2dip swap ; inline
153 : (tail) ( seq n -- from to seq ) swap [ length ] keep ; inline
155 : from-end ( seq n -- seq n' ) [ dup length ] dip - ; inline
157 : (1sequence) ( obj seq -- seq )
158 [ 0 swap set-nth-unsafe ] keep ; inline
160 : (2sequence) ( obj1 obj2 seq -- seq )
161 [ 1 swap set-nth-unsafe ] keep
164 : (3sequence) ( obj1 obj2 obj3 seq -- seq )
165 [ 2 swap set-nth-unsafe ] keep
168 : (4sequence) ( obj1 obj2 obj3 obj4 seq -- seq )
169 [ 3 swap set-nth-unsafe ] keep
174 : 1sequence ( obj exemplar -- seq )
175 1 swap [ (1sequence) ] new-like ; inline
177 : 2sequence ( obj1 obj2 exemplar -- seq )
178 2 swap [ (2sequence) ] new-like ; inline
180 : 3sequence ( obj1 obj2 obj3 exemplar -- seq )
181 3 swap [ (3sequence) ] new-like ; inline
183 : 4sequence ( obj1 obj2 obj3 obj4 exemplar -- seq )
184 4 swap [ (4sequence) ] new-like ; inline
186 : first2 ( seq -- first second )
187 1 swap bounds-check nip first2-unsafe ; flushable
189 : first3 ( seq -- first second third )
190 2 swap bounds-check nip first3-unsafe ; flushable
192 : first4 ( seq -- first second third fourth )
193 3 swap bounds-check nip first4-unsafe ; flushable
195 : ?nth ( n seq -- elt/f )
196 2dup bounds-check? [ nth-unsafe ] [ 2drop f ] if ; inline
198 MIXIN: virtual-sequence
199 GENERIC: virtual-seq ( seq -- seq' )
200 GENERIC: virtual@ ( n seq -- n' seq' )
202 M: virtual-sequence nth virtual@ nth ;
203 M: virtual-sequence set-nth virtual@ set-nth ;
204 M: virtual-sequence nth-unsafe virtual@ nth-unsafe ;
205 M: virtual-sequence set-nth-unsafe virtual@ set-nth-unsafe ;
206 M: virtual-sequence like virtual-seq like ;
207 M: virtual-sequence new-sequence virtual-seq new-sequence ;
209 INSTANCE: virtual-sequence sequence
211 ! A reversal of an underlying sequence.
212 TUPLE: reversed { seq read-only } ;
214 C: <reversed> reversed
216 M: reversed virtual-seq seq>> ;
218 M: reversed virtual@ seq>> [ length swap - 1 - ] keep ;
220 M: reversed length seq>> length ;
222 INSTANCE: reversed virtual-sequence
224 ! A slice of another sequence.
230 : collapse-slice ( m n slice -- m' n' seq )
231 [ from>> ] [ seq>> ] bi [ [ + ] curry bi@ ] dip ; inline
233 TUPLE: slice-error from to seq reason ;
235 : slice-error ( from to seq ? string -- from to seq )
236 [ \ slice-error boa throw ] curry when ; inline
238 : check-slice ( from to seq -- from to seq )
240 [ 2drop 0 < "start < 0" slice-error ]
241 [ [ drop ] 2dip length > "end > sequence" slice-error ]
242 [ drop > "start > end" slice-error ]
245 : <slice> ( from to seq -- slice )
246 dup slice? [ collapse-slice ] when
250 M: slice virtual-seq seq>> ;
252 M: slice virtual@ [ from>> + ] [ seq>> ] bi ;
254 M: slice length [ to>> ] [ from>> ] bi - ;
256 : short ( seq n -- seq n' ) over length min ; inline
258 : head-slice ( seq n -- slice ) (head) <slice> ; inline
260 : tail-slice ( seq n -- slice ) (tail) <slice> ; inline
262 : rest-slice ( seq -- slice ) 1 tail-slice ; inline
264 : head-slice* ( seq n -- slice ) from-end head-slice ; inline
266 : tail-slice* ( seq n -- slice ) from-end tail-slice ; inline
268 : but-last-slice ( seq -- slice ) 1 head-slice* ; inline
270 INSTANCE: slice virtual-sequence
272 ! One element repeated many times
273 TUPLE: repetition { len read-only } { elt read-only } ;
275 C: <repetition> repetition
277 M: repetition length len>> ;
278 M: repetition nth-unsafe nip elt>> ;
280 INSTANCE: repetition immutable-sequence
284 ERROR: integer-length-expected obj ;
286 : check-length ( n -- n )
288 dup integer? [ integer-length-expected ] unless ; inline
290 : ((copy)) ( dst i src j n -- dst i src j n )
292 + swap nth-unsafe -roll [
293 + swap set-nth-unsafe
297 : (copy) ( dst i src j n -- dst )
298 dup 0 <= [ 2drop 2drop ] [ 1 - ((copy)) (copy) ] if ;
301 : prepare-subseq ( from to seq -- dst i src j n )
302 #! The check-length call forces partial dispatch
303 [ [ swap - ] dip new-sequence dup 0 ] 3keep
304 -rot drop roll length check-length ; inline
306 : check-copy ( src n dst -- )
307 over 0 < [ bounds-error ] when
308 [ swap length + ] dip lengthen ; inline
312 : subseq ( from to seq -- subseq )
313 [ check-slice prepare-subseq (copy) ] keep like ;
315 : head ( seq n -- headseq ) (head) subseq ;
317 : tail ( seq n -- tailseq ) (tail) subseq ;
319 : rest ( seq -- tailseq ) 1 tail ;
321 : head* ( seq n -- headseq ) from-end head ;
323 : tail* ( seq n -- tailseq ) from-end tail ;
325 : but-last ( seq -- headseq ) 1 head* ;
327 : copy ( src i dst -- )
328 #! The check-length call forces partial dispatch
329 pick length check-length [ 3dup check-copy spin 0 ] dip
332 M: sequence clone-like
333 [ dup length ] dip new-sequence [ 0 swap copy ] keep ;
335 M: immutable-sequence clone-like like ;
337 : push-all ( src dest -- ) [ length ] [ copy ] bi ;
341 : (append) ( seq1 seq2 accum -- accum )
342 [ [ over length ] dip copy ]
348 : append-as ( seq1 seq2 exemplar -- newseq )
349 [ over length over length + ] dip
350 [ (append) ] new-like ; inline
352 : 3append-as ( seq1 seq2 seq3 exemplar -- newseq )
353 [ 3dup [ length ] tri@ + + ] dip [
354 [ [ 2over [ length ] bi@ + ] dip copy ]
358 : append ( seq1 seq2 -- newseq ) over append-as ;
360 : prepend ( seq1 seq2 -- newseq ) swap append ; inline
362 : 3append ( seq1 seq2 seq3 -- newseq ) pick 3append-as ;
364 : surround ( seq1 seq2 seq3 -- newseq ) swapd 3append ; inline
366 : glue ( seq1 seq2 seq3 -- newseq ) swap 3append ; inline
368 : change-nth ( i seq quot -- )
369 [ [ nth ] dip call ] 3keep drop set-nth ; inline
371 : min-length ( seq1 seq2 -- n ) [ length ] bi@ min ; inline
373 : max-length ( seq1 seq2 -- n ) [ length ] bi@ max ; inline
377 : ((each)) ( seq -- n quot )
378 [ length ] keep [ nth-unsafe ] curry ; inline
380 : (each) ( seq quot -- n quot' )
381 [ ((each)) ] dip compose ; inline
383 : (each-index) ( seq quot -- n quot' )
384 [ ((each)) [ keep ] curry ] dip compose ; inline
386 : (collect) ( quot into -- quot' )
387 [ [ keep ] dip set-nth-unsafe ] 2curry ; inline
389 : collect ( n quot into -- )
390 (collect) each-integer ; inline
392 : map-into ( seq quot into -- )
393 [ (each) ] dip collect ; inline
395 : 2nth-unsafe ( n seq1 seq2 -- elt1 elt2 )
396 [ nth-unsafe ] bi-curry@ bi ; inline
398 : (2each) ( seq1 seq2 quot -- n quot' )
401 [ 2nth-unsafe ] 2curry
402 ] dip compose ; inline
404 : 3nth-unsafe ( n seq1 seq2 seq3 -- elt1 elt2 elt3 )
405 [ nth-unsafe ] tri-curry@ tri ; inline
407 : (3each) ( seq1 seq2 seq3 quot -- n quot' )
409 [ [ length ] tri@ min min ]
410 [ [ 3nth-unsafe ] 3curry ] 3bi
411 ] dip compose ; inline
413 : finish-find ( i seq -- i elt )
414 over [ dupd nth-unsafe ] [ drop f ] if ; inline
416 : (find) ( seq quot quot' -- i elt )
417 pick [ [ (each) ] dip call ] dip finish-find ; inline
419 : (find-from) ( n seq quot quot' -- i elt )
420 [ 2dup bounds-check? ] 2dip
427 : each ( seq quot -- )
428 (each) each-integer ; inline
430 : reduce ( seq identity quot -- result )
433 : map-integers ( len quot exemplar -- newseq )
434 [ over ] dip [ [ collect ] keep ] new-like ; inline
436 : map-as ( seq quot exemplar -- newseq )
437 [ (each) ] dip map-integers ; inline
439 : map ( seq quot -- newseq )
442 : replicate ( seq quot -- newseq )
443 [ drop ] prepose map ; inline
445 : replicate-as ( seq quot exemplar -- newseq )
446 [ [ drop ] prepose ] dip map-as ; inline
448 : change-each ( seq quot -- )
449 over map-into ; inline
451 : accumulate ( seq identity quot -- final newseq )
452 swapd [ [ call ] [ 2drop ] 3bi ] curry { } map-as ; inline
454 : 2each ( seq1 seq2 quot -- )
455 (2each) each-integer ; inline
457 : 2reverse-each ( seq1 seq2 quot -- )
458 [ [ <reversed> ] bi@ ] dip 2each ; inline
460 : 2reduce ( seq1 seq2 identity quot -- result )
461 [ -rot ] dip 2each ; inline
463 : 2map-as ( seq1 seq2 quot exemplar -- newseq )
464 [ (2each) ] dip map-integers ; inline
466 : 2map ( seq1 seq2 quot -- newseq )
467 pick 2map-as ; inline
469 : 2all? ( seq1 seq2 quot -- ? )
470 (2each) all-integers? ; inline
472 : 3each ( seq1 seq2 seq3 quot -- )
473 (3each) each ; inline
475 : 3map-as ( seq1 seq2 seq3 quot exemplar -- newseq )
476 [ (3each) ] dip map-integers ; inline
478 : 3map ( seq1 seq2 seq3 quot -- newseq )
479 [ pick ] dip swap 3map-as ; inline
481 : find-from ( n seq quot -- i elt )
482 [ (find-integer) ] (find-from) ; inline
484 : find ( seq quot -- i elt )
485 [ find-integer ] (find) ; inline
487 : find-last-from ( n seq quot -- i elt )
488 [ nip find-last-integer ] (find-from) ; inline
490 : find-last ( seq quot -- i elt )
491 [ [ 1 - ] dip find-last-integer ] (find) ; inline
493 : all? ( seq quot -- ? )
494 (each) all-integers? ; inline
496 : push-if ( elt quot accum -- )
497 [ keep ] dip rot [ push ] [ 2drop ] if ; inline
499 : pusher ( quot -- quot accum )
500 V{ } clone [ [ push-if ] 2curry ] keep ; inline
502 : filter ( seq quot -- subseq )
503 over [ pusher [ each ] dip ] dip like ; inline
505 : push-either ( elt quot accum1 accum2 -- )
506 [ keep swap ] 2dip ? push ; inline
508 : 2pusher ( quot -- quot accum1 accum2 )
509 V{ } clone V{ } clone [ [ push-either ] 3curry ] 2keep ; inline
511 : partition ( seq quot -- trueseq falseseq )
512 over [ 2pusher [ each ] 2dip ] dip [ like ] curry bi@ ; inline
514 : accumulator ( quot -- quot' vec )
515 V{ } clone [ [ push ] curry compose ] keep ; inline
517 : produce-as ( pred quot exemplar -- seq )
518 [ accumulator [ while ] dip ] dip like ; inline
520 : produce ( pred quot -- seq )
521 { } produce-as ; inline
523 : follow ( obj quot -- seq )
524 [ dup ] swap [ keep ] curry produce nip ; inline
526 : each-index ( seq quot -- )
527 (each-index) each-integer ; inline
529 : interleave ( seq between quot -- )
530 pick empty? [ 3drop ] [
531 [ [ drop first-unsafe ] dip call ]
532 [ [ rest-slice ] 2dip [ bi* ] 2curry each ]
536 : map-index ( seq quot -- newseq )
537 [ dup length iota ] dip 2map ; inline
539 : reduce-index ( seq identity quot -- )
540 swapd each-index ; inline
542 : index ( obj seq -- n )
543 [ = ] with find drop ;
545 : index-from ( obj i seq -- n )
546 rot [ = ] curry find-from drop ;
548 : last-index ( obj seq -- n )
549 [ = ] with find-last drop ;
551 : last-index-from ( obj i seq -- n )
552 rot [ = ] curry find-last-from drop ;
554 : (indices) ( elt i obj accum -- )
555 [ swap [ = ] dip ] dip [ push ] 2curry when ; inline
557 : indices ( obj seq -- indices )
559 [ [ (indices) ] 2curry each-index ] keep ;
561 : nths ( indices seq -- seq' )
564 : any? ( seq quot -- ? )
565 find drop >boolean ; inline
567 : member? ( elt seq -- ? )
570 : memq? ( elt seq -- ? )
573 : remove ( elt seq -- newseq )
574 [ = not ] with filter ;
576 : remq ( elt seq -- newseq )
577 [ eq? not ] with filter ;
579 : sift ( seq -- newseq )
582 : harvest ( seq -- newseq )
583 [ empty? not ] filter ;
585 : mismatch ( seq1 seq2 -- i )
586 [ min-length iota ] 2keep
587 [ 2nth-unsafe = not ] 2curry
592 [ -rot 2nth-unsafe <=> ] [ [ length ] compare ] if* ;
594 : sequence= ( seq1 seq2 -- ? )
595 2dup [ length ] bi@ =
596 [ mismatch not ] [ 2drop f ] if ; inline
598 ERROR: assert-sequence got expected ;
600 : assert-sequence= ( a b -- )
601 2dup sequence= [ 2drop ] [ assert-sequence ] if ;
603 : sequence-hashcode-step ( oldhash newpart -- newhash )
605 [ -2 fixnum-shift-fast ] [ 5 fixnum-shift-fast ] bi
606 fixnum+fast fixnum+fast
607 ] keep fixnum-bitxor ; inline
609 : sequence-hashcode ( n seq -- x )
610 [ 0 ] 2dip [ hashcode* sequence-hashcode-step ] with each ; inline
612 M: reversed equal? over reversed? [ sequence= ] [ 2drop f ] if ;
614 M: slice equal? over slice? [ sequence= ] [ 2drop f ] if ;
616 : move ( to from seq -- )
618 [ 3drop ] [ [ nth swap ] [ set-nth ] bi ] if ; inline
622 : (filter-here) ( quot: ( elt -- ? ) store scan seq -- )
625 [ nth-unsafe pick call [ 1 + ] when ] 2keep
628 ] [ nip set-length drop ] if ; inline recursive
632 : filter-here ( seq quot -- )
633 swap [ 0 0 ] dip (filter-here) ; inline
635 : delete ( elt seq -- )
636 [ = not ] with filter-here ;
638 : delq ( elt seq -- )
639 [ eq? not ] with filter-here ;
641 : prefix ( seq elt -- newseq )
642 over [ over length 1 + ] dip [
643 [ 0 swap set-nth-unsafe ] keep
647 : suffix ( seq elt -- newseq )
648 over [ over length 1 + ] dip [
649 [ [ over length ] dip set-nth-unsafe ] keep
653 : last ( seq -- elt ) [ length 1 - ] [ nth ] bi ;
655 : set-last ( elt seq -- ) [ length 1 - ] keep set-nth ;
657 : pop* ( seq -- ) [ length 1 - ] [ shorten ] bi ;
661 : move-backward ( shift from to seq -- )
665 [ [ 2over + pick ] dip move [ 1 + ] dip ] keep
669 : move-forward ( shift from to seq -- )
673 [ [ pick [ dup dup ] dip + swap ] dip move 1 - ] keep
677 : (open-slice) ( shift from to seq ? -- )
679 [ [ 1 - ] bi@ ] dip move-forward
681 [ over - ] 2dip move-backward
684 : open-slice ( shift from seq -- )
688 pick over length + over
689 [ pick 0 > [ [ length ] keep ] dip (open-slice) ] 2dip
695 : delete-slice ( from to seq -- )
696 check-slice [ over [ - ] dip ] dip open-slice ;
698 : delete-nth ( n seq -- )
699 [ dup 1 + ] dip delete-slice ;
701 : snip ( from to seq -- head tail )
702 [ swap head ] [ swap tail ] bi-curry bi* ; inline
704 : snip-slice ( from to seq -- head tail )
705 [ swap head-slice ] [ swap tail-slice ] bi-curry bi* ; inline
707 : replace-slice ( new from to seq -- seq' )
708 snip-slice surround ;
710 : remove-nth ( n seq -- seq' )
711 [ [ { } ] dip dup 1 + ] dip replace-slice ;
714 [ length 1 - ] [ [ nth ] [ shorten ] 2bi ] bi ;
716 : exchange ( m n seq -- )
717 [ nip bounds-check 2drop ]
718 [ bounds-check 3drop ]
722 : reverse-here ( seq -- )
723 [ length 2/ iota ] [ length ] [ ] tri
724 [ [ over - 1 - ] dip exchange-unsafe ] 2curry each ;
726 : reverse ( seq -- newseq )
728 dup [ length ] keep new-sequence
730 [ reverse-here ] keep
733 : sum-lengths ( seq -- n )
734 0 [ length + ] reduce ;
736 : concat-as ( seq exemplar -- newseq )
738 [ sum-lengths over new-resizable ] keep
739 [ over push-all ] each
740 ] if-empty swap like ;
742 : concat ( seq -- newseq )
743 [ { } ] [ dup first concat-as ] if-empty ;
747 : joined-length ( seq glue -- n )
748 [ [ sum-lengths ] [ length 1 [-] ] bi ] dip length * + ;
752 : join ( seq glue -- newseq )
753 dup empty? [ concat-as ] [
755 2dup joined-length over new-resizable [
756 [ [ push-all ] 2curry ] [ [ nip push-all ] 2curry ] 2bi
762 : padding ( seq n elt quot -- newseq )
764 [ over length [-] dup 0 = [ drop ] ] dip
765 [ <repetition> ] curry
766 ] dip compose if ; inline
768 : pad-head ( seq n elt -- padded )
769 [ swap dup append-as ] padding ;
771 : pad-tail ( seq n elt -- padded )
774 : shorter? ( seq1 seq2 -- ? ) [ length ] bi@ < ;
776 : head? ( seq begin -- ? )
780 [ nip ] [ length head-slice ] 2bi sequence=
783 : tail? ( seq end -- ? )
787 [ nip ] [ length tail-slice* ] 2bi sequence=
790 : cut-slice ( seq n -- before-slice after-slice )
791 [ head-slice ] [ tail-slice ] 2bi ;
793 : insert-nth ( elt n seq -- seq' )
794 swap cut-slice [ swap suffix ] dip append ;
796 : midpoint@ ( seq -- n ) length 2/ ; inline
798 : halves ( seq -- first-slice second-slice )
799 dup midpoint@ cut-slice ;
801 : binary-reduce ( seq start quot: ( elt1 elt2 -- newelt ) -- value )
802 #! We can't use case here since combinators depends on
804 pick length dup 0 3 between? [
808 [ [ drop first2 ] dip call ]
809 [ [ drop first3 ] dip bi@ ]
814 [ [ binary-reduce ] 2curry bi@ ] keep
816 ] if ; inline recursive
818 : cut ( seq n -- before after )
819 [ head ] [ tail ] 2bi ;
821 : cut* ( seq n -- before after )
822 [ head* ] [ tail* ] 2bi ;
826 : (start) ( subseq seq n -- subseq seq ? )
828 [ 3dup ] dip [ + swap nth-unsafe ] keep rot nth-unsafe =
833 : start* ( subseq seq n -- i )
834 pick length pick length swap - 1 + iota
835 [ (start) ] find-from
838 : start ( subseq seq -- i ) 0 start* ; inline
840 : subseq? ( subseq seq -- ? ) start >boolean ;
842 : drop-prefix ( seq1 seq2 -- slice1 slice2 )
843 2dup mismatch [ 2dup min-length ] unless*
844 [ tail-slice ] curry bi@ ;
846 : unclip ( seq -- rest first )
847 [ rest ] [ first-unsafe ] bi ;
849 : unclip-last ( seq -- butlast last )
850 [ but-last ] [ last ] bi ;
852 : unclip-slice ( seq -- rest-slice first )
853 [ rest-slice ] [ first-unsafe ] bi ; inline
855 : 2unclip-slice ( seq1 seq2 -- rest-slice1 rest-slice2 first1 first2 )
856 [ unclip-slice ] bi@ swapd ; inline
858 : map-reduce ( seq map-quot reduce-quot -- result )
859 [ [ unclip-slice ] dip [ call ] keep ] dip
860 compose reduce ; inline
862 : 2map-reduce ( seq1 seq2 map-quot reduce-quot -- result )
863 [ [ 2unclip-slice ] dip [ call ] keep ] dip
864 compose 2reduce ; inline
868 : (map-find) ( seq quot find-quot -- result elt )
869 [ [ f ] 2dip [ [ nip ] dip call dup ] curry ] dip call
870 [ [ drop f ] unless ] dip ; inline
874 : map-find ( seq quot -- result elt )
875 [ find ] (map-find) ; inline
877 : map-find-last ( seq quot -- result elt )
878 [ find-last ] (map-find) ; inline
880 : unclip-last-slice ( seq -- butlast-slice last )
881 [ but-last-slice ] [ last ] bi ; inline
883 : <flat-slice> ( seq -- slice )
884 dup slice? [ { } like ] when
885 [ drop 0 ] [ length ] [ ] tri <slice> ;
890 : (trim-head) ( seq quot -- seq n )
891 over [ [ not ] compose find drop ] dip
892 [ length or ] keep swap ; inline
894 : (trim-tail) ( seq quot -- seq n )
895 over [ [ not ] compose find-last drop ?1+ ] dip
900 : trim-head-slice ( seq quot -- slice )
901 (trim-head) tail-slice ; inline
903 : trim-head ( seq quot -- newseq )
904 (trim-head) tail ; inline
906 : trim-tail-slice ( seq quot -- slice )
907 (trim-tail) head-slice ; inline
909 : trim-tail ( seq quot -- newseq )
910 (trim-tail) head ; inline
912 : trim-slice ( seq quot -- slice )
913 [ trim-head-slice ] [ trim-tail-slice ] bi ; inline
915 : trim ( seq quot -- newseq )
916 [ trim-slice ] [ drop ] 2bi like ; inline
918 : sum ( seq -- n ) 0 [ + ] binary-reduce ;
920 : product ( seq -- n ) 1 [ * ] binary-reduce ;
922 : infimum ( seq -- n ) [ ] [ min ] map-reduce ;
924 : supremum ( seq -- n ) [ ] [ max ] map-reduce ;
926 : sigma ( seq quot -- n )
927 [ 0 ] 2dip [ dip + ] curry [ swap ] prepose each ; inline
929 : count ( seq quot -- n ) [ 1 0 ? ] compose sigma ; inline
931 ! We hand-optimize flip to such a degree because type hints
932 ! cannot express that an array is an array of arrays yet, and
933 ! this word happens to be performance-critical since the compiler
934 ! itself uses it. Optimizing it like this reduced compile time.
937 : generic-flip ( matrix -- newmatrix )
938 [ dup first length [ length min ] reduce ] keep
939 [ [ nth-unsafe ] with { } map-as ] curry { } map-as ; inline
943 : array-length ( array -- len )
944 { array } declare length>> ; inline
946 : array-flip ( matrix -- newmatrix )
948 [ dup first array-length [ array-length min ] reduce ] keep
949 [ [ { array } declare array-nth ] with { } map-as ] curry { } map-as ;
953 : flip ( matrix -- newmatrix )
957 [ array-flip ] [ generic-flip ] if
958 ] [ generic-flip ] if