1 USING: accessors arrays assocs combinators generalizations
2 grouping growable heaps kernel math math.order ranges sequences
3 sequences.private shuffle sorting splitting vectors ;
6 : find-all ( ... seq quot: ( ... elt -- ... ? ) -- ... elts )
7 [ <enumerated> ] dip '[ nip @ ] assoc-filter ; inline
9 : reduce-from ( ... seq identity quot: ( ... prev elt -- ... next ) i -- ... result )
10 [ swap ] 2dip each-from ; inline
12 :: subseq* ( from to seq -- subseq )
14 from [ dup 0 < [ len + ] when ] [ 0 ] if*
15 to [ dup 0 < [ len + ] when ] [ len ] if*
16 [ 0 len clamp ] bi@ dupd max seq subseq ;
18 : safe-subseq ( from to seq -- subseq )
19 [ length '[ 0 _ clamp ] bi@ ] keep subseq ;
21 : all-subseqs ( seq -- seqs )
22 dup length [1..b] [ clump ] with map concat ;
24 : each-subseq ( ... seq quot: ( ... subseq -- ... ) -- ... )
25 [ dup length [ [0..b] ] [ ] bi ] dip '[
26 dup _ (a..b] [ rot [ subseq _ call ] keep ] with each
29 : map-like ( seq exemplar -- seq' )
30 '[ _ like ] map ; inline
32 : filter-all-subseqs-range ( ... seq range quot: ( ... subseq -- ... ? ) -- seq )
34 '[ <clumps> _ filter ] with map concat
35 ] keepdd map-like ; inline
37 : filter-all-subseqs ( ... seq quot: ( ... subseq -- ... ? ) -- seq )
38 [ dup length [1..b] ] dip filter-all-subseqs-range ; inline
40 :: longest-subseq ( seq1 seq2 -- subseq )
45 len1 1 + [ len2 1 + 0 <array> ] replicate :> table
49 y 1 - seq2 nth-unsafe = [
50 y 1 - x 1 - table nth-unsafe nth-unsafe 1 + :> len
51 len y x table nth-unsafe set-nth-unsafe
52 len n > [ len n! x end! ] when
53 ] [ 0 y x table nth-unsafe set-nth-unsafe ] if
55 ] each end n - end seq1 subseq ;
57 : pad-longest ( seq1 seq2 elt -- seq1 seq2 )
58 [ 2dup max-length ] dip [ pad-tail ] 2curry bi@ ;
60 : pad-center ( seq n elt -- padded )
61 swap pick length [-] [ drop ] [
62 [ 2/ ] [ over - ] bi rot '[ _ <repetition> ] bi@
66 : change-nths ( ... indices seq quot: ( ... elt -- ... elt' ) -- ... )
67 [ change-nth ] 2curry each ; inline
69 : push-if-index ( ..a elt i quot: ( ..a elt i -- ..b ? ) accum -- ..b )
70 [ keepd ] dip rot [ push ] [ 2drop ] if ; inline
72 : push-if* ( ..a elt quot: ( ..a elt -- ..b obj/f ) accum -- ..b )
73 [ call ] dip [ push ] [ drop ] if* ; inline
77 : (index-selector-as) ( quot length exampler -- selector accum )
78 new-resizable [ [ push-if-index ] 2curry ] keep ; inline
80 : (selector-as*) ( quot length exemplar -- selector accum )
81 new-resizable [ [ push-if* ] 2curry ] keep ; inline
85 : index-selector-as ( quot exemplar -- selector accum )
86 [ length ] keep (index-selector-as) ; inline
88 : index-selector ( quot -- selector accum )
89 V{ } index-selector-as ; inline
91 : selector-as* ( quot exemplar -- selector accum )
92 [ length ] keep (selector-as*) ; inline
94 : selector* ( quot -- selector accum ) V{ } selector-as* ; inline
96 : filter-index-as ( ... seq quot: ( ... elt i -- ... ? ) exemplar -- ... seq' )
97 pick length over [ (index-selector-as) [ each-index ] dip ] 2curry dip like ; inline
99 : filter-index ( ... seq quot: ( ... elt i -- ... ? ) -- ... seq' )
100 over filter-index-as ; inline
102 : even-indices ( seq -- seq' )
103 [ length 1 + 2/ ] keep [
104 [ [ 2 * ] dip nth-unsafe ] curry
105 ] keep map-integers-as ;
107 : odd-indices ( seq -- seq' )
109 [ [ 2 * 1 + ] dip nth-unsafe ] curry
110 ] keep map-integers-as ;
112 : compact ( ... seq quot: ( ... elt -- ... ? ) elt -- ... seq' )
113 [ split-when harvest ] dip join ; inline
115 : collapse ( ... seq quot: ( ... elt -- ... ? ) elt -- ... seq' )
117 [ [ harvest ] dip join ]
118 [ [ first empty? ] dip [ prepend ] curry when ]
119 [ [ last empty? ] dip [ append ] curry when ]
122 :: slice-when ( seq quot: ( elt -- ? ) -- seq' )
125 dup seq quot find-from drop
126 [ 2dup = [ 1 + ] when ] [ len ] if*
127 [ seq <slice> ] keep len or swap
128 ] produce nip ; inline
130 : ?<slice> ( from/f to/f sequence -- slice )
131 [ [ 0 ] unless* ] 2dip
132 over [ nip [ length ] [ ] bi ] unless
135 : sequence>slice ( sequence -- slice )
136 [ drop 0 ] [ length ] [ ] tri <slice> ; inline
138 : slice-order-by-from ( slice1 slice2 -- slice-lt slice-gt )
139 2dup [ from>> ] bi@ > [ swap ] when ; inline
141 : ordered-slices-range ( slice-lt slice-gt -- to from )
142 [ to>> ] [ from>> ] bi* ;
144 : unordered-slices-range ( slice1 slice2 -- to from )
145 slice-order-by-from ordered-slices-range ;
147 : ordered-slices-overlap? ( slice-lt slice-gt -- ? )
148 ordered-slices-range > ; inline
150 : unordered-slices-overlap? ( slice1 slice2 -- ? )
151 unordered-slices-range > ; inline
153 : slices-overlap? ( slice1 slice2 -- ? )
154 unordered-slices-overlap? ;
156 : ordered-slices-touch? ( slice-lt slice-gt -- ? )
157 ordered-slices-range >= ; inline
159 : unordered-slices-touch? ( slice1 slice2 -- ? )
160 unordered-slices-range >= ; inline
162 : slices-touch? ( slice1 slice2 -- ? )
163 unordered-slices-touch? ;
165 ERROR: slices-don't-touch slice1 slice2 ;
167 : merge-slices ( slice1 slice2 -- slice/* )
169 2dup ordered-slices-touch? [
170 [ from>> ] [ [ to>> ] [ seq>> ] bi ] bi* <slice>
175 : rotate ( seq n -- seq' )
176 over length mod dup 0 >= [ cut ] [ abs cut* ] if prepend ;
178 ERROR: underlying-mismatch slice1 slice2 ;
180 : ensure-same-underlying ( slice1 slice2 -- slice1 slice2 )
181 2dup [ seq>> ] bi@ eq? [ underlying-mismatch ] unless ;
183 : span-slices ( slice1 slice2 -- slice )
184 ensure-same-underlying
185 [ [ from>> ] bi@ min ]
187 [ drop seq>> ] 2tri <slice> ;
189 : ?span-slices ( slice1/f slice2/f -- slice )
190 2dup and [ span-slices ] [ or ] if ;
192 :: rotate! ( seq n -- )
194 n len mod dup 0 < [ len + ] when seq bounds-check drop 0 over
196 [ seq exchange-unsafe ] [ [ 1 + ] bi@ ] 2bi
197 dup len = [ drop over ] when
198 2over = [ -rot nip over ] when
201 : all-rotations ( seq -- seq' )
202 dup length <iota> [ rotate ] with map ;
206 : (appender-for) ( quot length exemplar -- appender accum )
207 new-resizable [ [ push-all ] curry compose ] keep ; inline
211 : appender-for ( quot exemplar -- appender accum )
212 [ length ] keep (appender-for) ; inline
214 : appender ( quot -- appender accum )
215 V{ } appender-for ; inline
217 : map-concat-as ( ... seq quot: ( ... elt -- ... newelt ) exemplar -- ... newseq )
218 [ appender-for [ each ] dip ] keep like ; inline
220 : >resizable ( seq -- accum ) ! fixes map-concat "cannot apply call to run-time..."
221 [ length ] keep [ new-resizable ] [ append! ] bi ;
223 : map-concat ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
224 over empty? [ 2drop { } ] [
225 [ [ first ] dip call ] 2keep rot [
226 >resizable [ '[ @ _ push-all ] 1 each-from ] keep
230 : map-filter-as ( ... seq map-quot: ( ... elt -- ... newelt ) filter-quot: ( ... newelt -- ... ? ) exemplar -- ... subseq )
232 [ (selector-as) [ compose each ] dip ] 2curry dip like ; inline
234 : map-filter ( ... seq map-quot: ( ... elt -- ... newelt ) filter-quot: ( ... newelt -- ... ? ) -- ... subseq )
235 pick map-filter-as ; inline
237 : map-sift ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
238 [ ] map-filter ; inline
240 : map-harvest ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
241 [ empty? not ] map-filter ; inline
243 : (each-integer-with-previous) ( ... prev i n quot: ( ... i -- ... ) -- ... )
245 [ nip call ] 4keep nipdd
246 [ 1 + ] 2dip (each-integer-with-previous)
249 ] if ; inline recursive
251 : each-integer-with-previous ( ... n quot: ( ... i -- ... ) -- ... )
252 [ f 0 ] 2dip (each-integer-with-previous) ; inline
254 : (collect-with-previous) ( quot into -- quot' )
255 [ [ keep ] dip [ set-nth-unsafe ] keepdd ] 2curry ; inline
257 : collect-with-previous ( n quot into -- )
258 (collect-with-previous) each-integer-with-previous ; inline
260 : map-integers-with ( ... len quot: ( ... prev i -- ... elt ) exemplar -- ... newseq )
261 overd [ [ collect-with-previous ] keep ] new-like ; inline
263 : map-with-previous-as ( ... seq quot: ( ... elt prev/f -- ... newelt ) exemplar -- ... newseq )
264 [ length-operator ] dip map-integers-with ; inline
266 : map-with-previous ( ... seq quot: ( ... elt prev/f -- ... newelt ) -- ... newseq )
267 over map-with-previous-as ; inline
271 : (setup-each-from) ( i seq -- n quot )
272 [ length over [-] swap ] keep '[ _ + _ nth-unsafe ] ; inline
274 : setup-each-from ( i seq quot -- n quot' )
275 [ (setup-each-from) ] dip compose ; inline
279 : map-from-as ( ... seq quot: ( ... elt -- ... newelt ) i exemplar -- ... newseq )
280 [ -rot setup-each-from ] dip map-integers-as ; inline
282 : map-from ( ... seq quot: ( ... elt -- ... newelt ) i -- ... newseq )
283 pick map-from-as ; inline
287 : push-map-if ( ..a elt filter-quot: ( ..a elt -- ..b ? ) map-quot: ( ..a elt -- ..b newelt ) accum -- ..b )
288 [ keep over ] 2dip [ when ] dip rot [ push ] [ 2drop ] if ; inline
290 : (filter-mapper-for) ( filter-quot map-quot length exempler -- filter-mapper accum )
291 new-resizable [ [ push-map-if ] 3curry ] keep ; inline
293 : filter-mapper-for ( filter-quot map-quot exemplar -- filter-mapper accum )
294 [ length ] keep (filter-mapper-for) ; inline
296 : filter-mapper ( filter-quot map-quot -- filter-mapper accum )
297 V{ } filter-mapper-for ; inline
301 : filter-map-as ( ... seq filter-quot: ( ... elt -- ... ? ) map-quot: ( ... elt -- ... newelt ) exemplar -- ... newseq )
303 [ (filter-mapper-for) [ each ] dip ] 2curry dip like ; inline
305 : filter-map ( ... seq filter-quot: ( ... elt -- ... ? ) map-quot: ( ... elt -- ... newelt ) -- ... newseq )
306 pick filter-map-as ; inline
308 : 2map-sum ( ... seq1 seq2 quot: ( ... elt1 elt2 -- ... n ) -- ... n )
309 [ 0 ] 3dip [ dip + ] curry [ rot ] prepose 2each ; inline
311 : 2count ( ... seq1 seq2 quot: ( ... elt1 elt2 -- ... ? ) -- ... n )
312 [ 1 0 ? ] compose 2map-sum ; inline
315 ( ... seq1 seq2 seq3 quot: ( ... elt1 elt2 elt3 -- ... ) i -- ... )
316 [ (3each) ] dip -rot each-integer-from ; inline
319 ( ..a seq1 seq2 seq3 map-quot: ( ..a elt1 elt2 elt3 -- ..b intermediate ) reduce-quot: ( ..b prev intermediate -- ..a next ) -- ..a result )
320 [ [ [ [ first ] tri@ ] 3keep ] dip [ 3dip ] keep ] dip compose 1 3each-from ; inline
322 : round-robin ( seq -- newseq )
324 [ longest length <iota> ] keep
325 [ [ ?nth ] with map ] curry map concat sift
328 : sift-as ( seq exemplar -- newseq )
331 : sift! ( seq -- newseq )
334 : harvest-as ( seq exemplar -- newseq )
335 [ empty? not ] swap filter-as ;
337 : harvest! ( seq -- newseq )
340 : head-as ( seq n exemplar -- seq' )
341 [ head-slice ] [ like ] bi* ; inline
343 : head*-as ( seq n exemplar -- seq' )
344 [ head-slice* ] [ like ] bi* ; inline
346 : tail-as ( seq n exemplar -- seq' )
347 [ tail-slice ] [ like ] bi* ; inline
349 : tail*-as ( seq n exemplar -- seq' )
350 [ tail-slice* ] [ like ] bi* ; inline
352 : trim-as ( ... seq quot: ( ... elt -- ... ? ) exemplar -- ... newseq )
353 [ trim-slice ] [ like ] bi* ; inline
355 : ?trim ( seq quot: ( elt -- ? ) -- seq/newseq )
356 over empty? [ drop ] [
357 over [ first-unsafe ] [ last-unsafe ] bi pick either?
361 : ?trim-head ( seq quot: ( elt -- ? ) -- seq/newseq )
362 over empty? [ drop ] [
363 over first-unsafe over call
364 [ trim-head ] [ drop ] if
367 : ?trim-tail ( seq quot: ( elt -- ? ) -- seq/newseq )
368 over empty? [ drop ] [
369 over last-unsafe over call
370 [ trim-tail ] [ drop ] if
373 : unsurround ( newseq seq2 seq3 -- seq1 )
374 [ ?head drop ] [ ?tail drop ] bi* ;
376 : >string-list ( seq -- seq' )
377 [ "\"" 1surround ] map "," join ;
379 : one? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? )
381 [ 1 + ] 2dip find-from drop not
382 ] [ 3drop f ] if ; inline
384 : map-index! ( ... seq quot: ( ... elt index -- ... newelt ) -- ... seq )
385 over [ [ sequence-index-iterator ] dip collect ] keep ; inline
389 : (2each-index) ( seq1 seq2 quot -- n quot' )
390 [ setup-2each [ keep ] curry ] dip compose ; inline
394 : 2each-index ( ... seq1 seq2 quot: ( ... elt1 elt2 index -- ... ) -- ... )
395 (2each-index) each-integer ; inline
397 : 2map-into ( seq1 seq2 quot into -- )
398 [ (2each) ] dip collect ; inline
400 : 2map! ( ... seq1 seq2 quot: ( ... elt1 elt2 -- ... newelt ) -- ... seq1 )
401 pick [ 2map-into ] keep ; inline
403 : 2map-index ( ... seq1 seq2 quot: ( ... elt1 elt2 index -- ... newelt ) -- ... newseq )
404 pick [ (2each-index) ] dip map-integers-as ; inline
406 TUPLE: evens { seq read-only } ;
410 M: evens length seq>> length 1 + 2/ ; inline
412 M: evens virtual@ [ 2 * ] [ seq>> ] bi* ; inline
414 M: evens virtual-exemplar seq>> ; inline
416 INSTANCE: evens virtual-sequence
418 TUPLE: odds { seq read-only } ;
422 M: odds length seq>> length 2/ ; inline
424 M: odds virtual@ [ 2 * 1 + ] [ seq>> ] bi* ; inline
426 M: odds virtual-exemplar seq>> ; inline
428 INSTANCE: odds virtual-sequence
430 : until-empty ( seq quot -- )
431 [ dup empty? ] swap until drop ; inline
435 : push-index-if ( ..a elt i quot: ( ..a elt -- ..b ? ) accum -- ..b )
436 [ dip ] dip rot [ push ] [ 2drop ] if ; inline
440 : arg-where ( ... seq quot: ( ... elt -- ... ? ) -- ... indices )
441 over length <vector> [
442 [ push-index-if ] 2curry each-index
445 : arg-sort ( seq -- indices )
446 zip-index sort-keys values ;
448 : first= ( seq elt -- ? ) [ first ] dip = ; inline
449 : second= ( seq elt -- ? ) [ second ] dip = ; inline
450 : third= ( seq elt -- ? ) [ third ] dip = ; inline
451 : fourth= ( seq elt -- ? ) [ fourth ] dip = ; inline
452 : last= ( seq elt -- ? ) [ last ] dip = ; inline
453 : nth= ( n seq elt -- ? ) [ nth ] dip = ; inline
455 : first? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ first ] dip call ; inline
456 : second? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ second ] dip call ; inline
457 : third? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ third ] dip call ; inline
458 : fourth? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ fourth ] dip call ; inline
459 : last? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ last ] dip call ; inline
460 : nth? ( ... n seq quot: ( ... elt -- ... ? ) -- ... ? ) [ nth ] dip call ; inline
462 : loop>sequence** ( ... quot: ( ... -- ... obj ? ) exemplar -- ... seq )
463 [ ] swap produce-as nip ; inline
465 : loop>array** ( ... quot: ( ... -- ... obj ? ) -- ... array )
466 { } loop>sequence** ; inline
468 : loop>sequence* ( ... quot: ( ... -- ... obj ? ) exemplar -- ... seq )
469 [ t ] [ '[ [ _ dip ] [ f f f ] if* ] [ swap ] ] [ produce-as 2nip ] tri* ; inline
471 : loop>array* ( ... quot: ( ... -- ... obj ? ) -- ... array )
472 { } loop>sequence* ; inline
474 : loop>sequence ( ... quot: ( ... -- ... obj/f ) exemplar -- ... seq )
475 [ [ dup ] compose [ ] ] dip produce-as nip ; inline
477 : loop>array ( ... quot: ( ... -- ... obj/f ) -- ... array )
478 { } loop>sequence ; inline
480 : zero-loop>sequence ( ... quot: ( ... n -- ... obj/f ) exemplar -- ... seq )
481 [ 0 ] [ '[ _ keep 1 + swap ] ] [ loop>sequence ] tri* nip ; inline
483 : zero-loop>array ( quot: ( ..a n -- ..a obj ) -- seq )
484 { } zero-loop>sequence ; inline
486 : iterate-heap-while ( heap quot1: ( value key -- slurp? ) quot2: ( value key -- obj/f ) -- obj/f loop? )
490 [ [ heap-peek ] 2dip drop 2keep ]
492 nip ! ( pop? value key heap quot2 )
494 swap heap-pop* call( value key -- obj/f ) t
501 : slurp-heap-while-map ( heap quot1: ( value key -- slurp? ) quot2: ( value key -- obj/f ) -- seq )
502 '[ _ _ _ iterate-heap-while ] loop>array* ; inline
504 : heap>pairs ( heap -- pairs )
505 [ 2drop t ] [ swap 2array ] slurp-heap-while-map ;
507 : map-zip-swap ( quot: ( x -- y ) -- alist )
508 '[ _ keep ] map>alist ; inline
510 : ?heap-pop-value>array ( heap -- array )
511 dup heap-empty? [ drop { } ] [ heap-pop drop 1array ] if ;
515 : (reverse) ( seq -- newseq )
516 dup [ length ] keep new-sequence
517 [ 0 swap copy-unsafe ] keep reverse! ;
521 : reverse-as ( seq exemplar -- newseq )
522 [ (reverse) ] [ like ] bi* ;
524 : map-product ( ... seq quot: ( ... elt -- ... n ) -- ... n )
525 [ 1 ] 2dip [ dip * ] curry [ swap ] prepose each ; inline
527 : insert-nth! ( elt n seq -- )
528 [ length ] keep ensure swap pick (a..b]
529 over '[ [ 1 + ] keep _ move-unsafe ] each
532 : set-nths ( value indices seq -- )
533 swapd '[ _ swap _ set-nth ] each ; inline
535 : set-nths-unsafe ( value indices seq -- )
536 swapd '[ _ swap _ set-nth-unsafe ] each ; inline
540 : (map-find-index) ( seq quot find-quot -- result i elt )
541 [ [ f ] 2dip [ [ nip ] 2dip call dup ] curry ] dip call
542 [ [ [ drop f ] unless ] keep ] dip ; inline
546 : map-find-index ( ... seq quot: ( ... elt index -- ... result/f ) -- ... result i elt )
547 [ find-index ] (map-find-index) ; inline
549 : filter-length ( seq n -- seq' ) '[ length _ = ] filter ;
551 : all-shortest ( seqs -- seqs' ) dup shortest length filter-length ;
553 : all-longest ( seqs -- seqs' ) dup longest length filter-length ;
555 : remove-first ( obj seq -- seq' )
556 [ index ] keep over [ remove-nth ] [ nip ] if ;
558 : remove-first! ( obj seq -- seq )
559 [ index ] keep over [ remove-nth! ] [ nip ] if ;
561 : remove-last ( obj seq -- seq' )
562 [ last-index ] keep over [ remove-nth ] [ nip ] if ;
564 : remove-last! ( obj seq -- seq )
565 [ last-index ] keep over [ remove-nth! ] [ nip ] if ;
567 : ?first2 ( seq -- first/f second/f )
570 { 1 [ first-unsafe f ] }
571 [ drop first2-unsafe ]
574 : ?first3 ( seq -- first/f second/f third/f )
577 { 1 [ first-unsafe f f ] }
578 { 2 [ first2-unsafe f ] }
579 [ drop first3-unsafe ]
582 : ?first4 ( seq -- first/f second/f third/f fourth/f )
584 { 0 [ drop f f f f ] }
585 { 1 [ first-unsafe f f f ] }
586 { 2 [ first2-unsafe f f ] }
587 { 3 [ first3-unsafe f ] }
588 [ drop first4-unsafe ]
591 : cut-when ( ... seq quot: ( ... elt -- ... ? ) -- ... before after )
592 [ find drop ] keepd swap
593 [ cut ] [ f over like ] if* ; inline
595 : nth* ( n seq -- elt )
596 [ length 1 - swap - ] [ nth ] bi ; inline
598 : each-index-from ( ... seq quot: ( ... elt index -- ... ) i -- ... )
599 -rot sequence-index-iterator each-integer-from ; inline
603 : select-by* ( ... seq quot: ( ... elt -- ... x ) compare: ( obj1 obj2 -- ? ) -- ... i elt )
605 [ keep swap ] curry [ dip ] curry
606 [ [ first 0 ] dip call ] 2keep
607 [ 2curry 3dip 5 npick pick ] curry
609 [ [ 3drop ] [ [ 3drop ] 3dip ] if ] compose
610 ] bi* compose 1 each-index-from nip swap ; inline
614 : supremum-by* ( ... seq quot: ( ... elt -- ... x ) -- ... i elt )
615 [ after? ] select-by* ; inline
617 : infimum-by* ( ... seq quot: ( ... elt -- ... x ) -- ... i elt )
618 [ before? ] select-by* ; inline
620 : arg-max ( seq -- n )
621 [ ] supremum-by* drop ;
623 : arg-min ( seq -- n )
624 [ ] infimum-by* drop ;
626 : ?supremum ( seq/f -- elt/f )
628 [ ] [ 2dup and [ max ] [ dupd ? ] if ] map-reduce
631 : ?infimum ( seq/f -- elt/f )
633 [ ] [ 2dup and [ min ] [ dupd ? ] if ] map-reduce
636 : change-last ( seq quot -- )
637 [ drop length 1 - ] [ change-nth ] 2bi ; inline
639 : change-last-unsafe ( seq quot -- )
640 [ drop length 1 - ] [ change-nth-unsafe ] 2bi ; inline
642 : replicate-into ( ... seq quot: ( ... -- ... newelt ) -- ... )
643 over [ length ] 2dip '[ _ dip _ set-nth-unsafe ] each-integer ; inline
645 : count* ( ... seq quot: ( ... elt -- ... ? ) -- ... % )
646 over [ count ] [ length ] bi* / ; inline
648 : find-last-index ( ... seq quot: ( ... elt i -- ... ? ) -- ... i elt )
649 [ [ 1 - ] dip find-last-integer ] (find-index) ; inline
651 : map-find-last-index ( ... seq quot: ( ... elt index -- ... result/f ) -- ... result i elt )
652 [ find-last-index ] (map-find-index) ; inline
654 :: (start-all) ( seq subseq increment -- indices )
656 [ seq subseq find-subseq-from dup ]
657 [ [ increment + ] keep ] produce nip ;
659 : start-all ( seq subseq -- indices )
660 dup length (start-all) ; inline
662 : start-all* ( seq subseq -- indices )
663 1 (start-all) ; inline
665 : count-subseq ( seq subseq -- n )
666 start-all length ; inline
668 : count-subseq* ( seq subseq -- n )
669 start-all* length ; inline
671 : assoc-zip-with ( quot: ( key value -- calc ) -- alist )
672 '[ _ 2keep 2array swap ] assoc-map ; inline
674 : take-while ( ... seq quot: ( ... elt -- ... ? ) -- head-slice )
675 [ '[ @ not ] find drop ] keepd swap
676 [ dup length ] unless* head-slice ; inline
678 : drop-while ( ... seq quot: ( ... elt -- ... ? ) -- tail-slice )
679 [ '[ @ not ] find drop ] keepd swap
680 [ dup length ] unless* tail-slice ; inline
682 : count-head ( seq quot -- n )
683 [ not ] compose [ find drop ] keepd length or ; inline
685 : count-tail ( seq quot -- n )
686 [ not ] compose [ find-last drop ] keepd
687 length swap [ - 1 - ] when* ; inline
689 :: shorten* ( vector n -- seq )
693 :: interleaved-as ( seq glue exemplar -- newseq )
694 seq length dup 1 - + 0 max exemplar new-sequence :> newseq
695 seq [ 2 * newseq set-nth-unsafe ] each-index
696 seq length 1 - [ 2 * 1 + glue swap newseq set-nth-unsafe ] each-integer
699 : interleaved ( seq glue -- newseq )
700 over interleaved-as ;
702 : extract! ( ... seq quot: ( ... elt -- ... ? ) -- ... seq )
703 [ dup ] compose over [ length ] keep new-resizable
704 [ [ push-if ] 2curry reject! ] keep swap like ; inline
706 : find-pred-loop ( ... i n seq quot: ( ... elt -- ... calc ? ) -- ... calc/f i/f elt/f )
710 [ [ 3drop ] 2dip rot ]
711 [ 2drop [ 1 + ] 3dip find-pred-loop ] if
714 ] if ; inline recursive
716 : find-pred ( ... seq quot: ( ... elt -- ... calc ) pred: ( ... calc -- ... ? ) -- ... calc/f i/f elt/f )
718 [ [ length check-length ] keep ] 2dip
719 '[ nth-unsafe _ keep swap _ keep swap ] find-pred-loop swapd ; inline
721 ! https://en.wikipedia.org/wiki/Maximum_subarray_problem
722 ! Kadane's algorithm O(n) largest sum in subarray
723 : max-subarray-sum ( seq -- sum )
725 [ [ + ] keep max [ max ] keep ] each drop ;
728 { from integer read-only initial: 0 }
729 { to integer read-only initial: 0 }
731 { step integer read-only } ;
733 :: <step-slice> ( from to step seq -- step-slice )
734 step zero? [ "can't be zero" throw ] when
743 [ dup 0 < [ len + ] when 0 len clamp ] bi@
744 ! FIXME: make this work with steps
745 seq dup slice? [ collapse-slice ] when
746 step step-slice boa ;
748 M: step-slice virtual-exemplar seq>> ; inline
750 M: step-slice virtual@
751 [ step>> * ] [ from>> + ] [ seq>> ] tri ; inline
754 [ to>> ] [ from>> - ] [ step>> ] tri
755 dup 0 < [ [ neg 0 max ] dip neg ] when /mod
756 zero? [ 1 + ] unless ; inline
758 INSTANCE: step-slice virtual-sequence