1 USING: accessors arrays assocs combinators fry generalizations
2 grouping growable kernel locals make math math.order math.ranges
3 sequences sequences.deep sequences.private sorting splitting
7 : find-all ( ... seq quot: ( ... elt -- ... ? ) -- ... elts )
8 [ <enumerated> ] dip '[ nip @ ] assoc-filter ; inline
10 : reduce-from ( ... seq identity quot: ( ... prev elt -- ... next ) i -- ... result )
11 [ swap ] 2dip each-from ; inline
13 :: subseq* ( from to seq -- subseq )
15 from [ dup 0 < [ len + ] when ] [ 0 ] if*
16 to [ dup 0 < [ len + ] when ] [ len ] if*
17 [ 0 len clamp ] bi@ dupd max seq subseq ;
19 : safe-subseq ( from to seq -- subseq )
20 [ length '[ 0 _ clamp ] bi@ ] keep subseq ;
22 : all-subseqs ( seq -- seqs )
23 dup length [1,b] [ clump ] with map concat ;
25 :: each-subseq ( ... seq quot: ( ... subseq -- ... ) -- ... )
28 from len (a,b] [| to |
29 from to seq subseq quot call
33 : map-like ( seq exemplar -- seq' )
34 '[ _ like ] map ; inline
36 : filter-all-subseqs-range ( ... seq range quot: ( ... subseq -- ... ) -- seq )
38 '[ <clumps> _ filter ] with map concat
39 ] keepdd map-like ; inline
41 : filter-all-subseqs ( ... seq quot: ( ... subseq -- ... ) -- seq )
42 [ dup length [1,b] ] dip filter-all-subseqs-range ; inline
44 :: longest-subseq ( seq1 seq2 -- subseq )
49 len1 1 + [ len2 1 + 0 <array> ] replicate :> table
53 y 1 - seq2 nth-unsafe = [
54 y 1 - x 1 - table nth-unsafe nth-unsafe 1 + :> len
55 len y x table nth-unsafe set-nth-unsafe
56 len n > [ len n! x end! ] when
57 ] [ 0 y x table nth-unsafe set-nth-unsafe ] if
59 ] each end n - end seq1 subseq ;
61 : pad-longest ( seq1 seq2 elt -- seq1 seq2 )
62 [ 2dup max-length ] dip [ pad-tail ] 2curry bi@ ;
64 :: pad-center ( seq n elt -- padded )
65 n seq length [-] :> extra
68 left elt <repetition> seq right elt <repetition>
71 : change-nths ( ... indices seq quot: ( ... elt -- ... elt' ) -- ... )
72 [ change-nth ] 2curry each ; inline
74 : push-if-index ( ..a elt i quot: ( ..a elt i -- ..b ? ) accum -- ..b )
75 [ keepd ] dip rot [ push ] [ 2drop ] if ; inline
77 : push-if* ( ..a elt quot: ( ..a elt -- ..b obj/f ) accum -- ..b )
78 [ call ] dip [ push ] [ drop ] if* ; inline
82 : (index-selector-as) ( quot length exampler -- selector accum )
83 new-resizable [ [ push-if-index ] 2curry ] keep ; inline
85 : (selector-as*) ( quot length exemplar -- selector accum )
86 new-resizable [ [ push-if* ] 2curry ] keep ; inline
90 : index-selector-as ( quot exemplar -- selector accum )
91 [ length ] keep (index-selector-as) ; inline
93 : index-selector ( quot -- selector accum )
94 V{ } index-selector-as ; inline
96 : selector-as* ( quot exemplar -- selector accum )
97 [ length ] keep (selector-as*) ; inline
99 : selector* ( quot -- selector accum ) V{ } selector-as* ; inline
101 : filter-index-as ( ... seq quot: ( ... elt i -- ... ? ) exemplar -- ... seq' )
102 pick length over [ (index-selector-as) [ each-index ] dip ] 2curry dip like ; inline
104 : filter-index ( ... seq quot: ( ... elt i -- ... ? ) -- ... seq' )
105 over filter-index-as ; inline
107 : even-indices ( seq -- seq' )
108 [ length 1 + 2/ ] keep [
109 [ [ 2 * ] dip nth-unsafe ] curry
110 ] keep map-integers ;
112 : odd-indices ( seq -- seq' )
114 [ [ 2 * 1 + ] dip nth-unsafe ] curry
115 ] keep map-integers ;
117 : compact ( ... seq quot: ( ... elt -- ... ? ) elt -- ... seq' )
118 [ split-when harvest ] dip join ; inline
120 : collapse ( ... seq quot: ( ... elt -- ... ? ) elt -- ... seq' )
122 [ [ harvest ] dip join ]
123 [ [ first empty? ] dip [ prepend ] curry when ]
124 [ [ last empty? ] dip [ append ] curry when ]
127 :: slice-when ( seq quot: ( elt -- ? ) -- seq' )
130 dup seq quot find-from drop
131 [ 2dup = [ 1 + ] when ] [ len ] if*
132 [ seq <slice> ] keep len or swap
133 ] produce nip ; inline
135 : cut-slice* ( seq n -- before after )
136 [ head-slice* ] [ tail-slice* ] 2bi ;
138 : ?<slice> ( from/f to/f sequence -- slice )
139 [ [ 0 ] unless* ] 2dip
140 over [ nip [ length ] [ ] bi ] unless
143 : sequence>slice ( sequence -- slice )
144 [ drop 0 ] [ length ] [ ] tri <slice> ; inline
146 : slice-order-by-from ( slice1 slice2 -- slice-lt slice-gt )
147 2dup [ from>> ] bi@ > [ swap ] when ; inline
149 : ordered-slices-range ( slice-lt slice-gt -- to from )
150 [ to>> ] [ from>> ] bi* ;
152 : unordered-slices-range ( slice1 slice2 -- to from )
153 slice-order-by-from ordered-slices-range ;
155 : ordered-slices-overlap? ( slice-lt slice-gt -- ? )
156 ordered-slices-range > ; inline
158 : unordered-slices-overlap? ( slice1 slice2 -- ? )
159 unordered-slices-range > ; inline
161 : slices-overlap? ( slice1 slice2 -- ? )
162 unordered-slices-overlap? ;
164 : ordered-slices-touch? ( slice-lt slice-gt -- ? )
165 ordered-slices-range >= ; inline
167 : unordered-slices-touch? ( slice1 slice2 -- ? )
168 unordered-slices-range >= ; inline
170 : slices-touch? ( slice1 slice2 -- ? )
171 unordered-slices-touch? ;
173 ERROR: slices-don't-touch slice1 slice2 ;
175 : merge-slices ( slice1 slice2 -- slice/* )
177 2dup ordered-slices-touch? [
178 [ from>> ] [ [ to>> ] [ seq>> ] bi ] bi* <slice>
183 : rotate ( seq n -- seq' )
184 over length mod dup 0 >= [ cut ] [ abs cut* ] if prepend ;
186 ERROR: underlying-mismatch slice1 slice2 ;
188 : ensure-same-underlying ( slice1 slice2 -- slice1 slice2 )
189 2dup [ seq>> ] bi@ eq? [ underlying-mismatch ] unless ;
191 : span-slices ( slice1 slice2 -- slice )
192 ensure-same-underlying
193 [ [ from>> ] bi@ min ]
195 [ drop seq>> ] 2tri <slice> ;
197 : ?span-slices ( slice1/f slice2/f -- slice )
198 2dup and [ span-slices ] [ or ] if ;
200 :: rotate! ( seq n -- )
202 n len mod dup 0 < [ len + ] when seq bounds-check drop 0 over
204 [ seq exchange-unsafe ] [ [ 1 + ] bi@ ] 2bi
205 dup len = [ drop over ] when
206 2over = [ -rot nip over ] when
209 : all-rotations ( seq -- seq' )
210 dup length <iota> [ rotate ] with map ;
214 : (appender-for) ( quot length exemplar -- appender accum )
215 new-resizable [ [ push-all ] curry compose ] keep ; inline
219 : appender-for ( quot exemplar -- appender accum )
220 [ length ] keep (appender-for) ; inline
222 : appender ( quot -- appender accum )
223 V{ } appender-for ; inline
225 : map-concat-as ( ... seq quot: ( ... elt -- ... newelt ) exemplar -- ... newseq )
226 [ appender-for [ each ] dip ] keep like ; inline
228 : >resizable ( seq -- accum ) ! fixes map-concat "cannot apply call to run-time..."
229 [ length ] keep [ new-resizable ] [ append! ] bi ;
231 : map-concat ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
232 over empty? [ 2drop { } ] [
233 [ [ first ] dip call ] 2keep rot [
234 >resizable [ '[ @ _ push-all ] 1 each-from ] keep
238 : map-filter-as ( ... seq map-quot: ( ... elt -- ... newelt ) filter-quot: ( ... newelt -- ... ? ) exemplar -- ... subseq )
240 [ (selector-as) [ compose each ] dip ] 2curry dip like ; inline
242 : map-filter ( ... seq map-quot: ( ... elt -- ... newelt ) filter-quot: ( ... newelt -- ... ? ) -- ... subseq )
243 pick map-filter-as ; inline
245 : map-sift ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
246 [ ] map-filter ; inline
248 : map-harvest ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
249 [ empty? not ] map-filter ; inline
253 : (setup-each-from) ( i seq -- n quot )
254 [ length over [-] swap ] keep '[ _ + _ nth-unsafe ] ; inline
256 : setup-each-from ( i seq quot -- n quot' )
257 [ (setup-each-from) ] dip compose ; inline
261 : map-from-as ( ... seq quot: ( ... elt -- ... newelt ) i exemplar -- ... newseq )
262 [ -rot setup-each-from ] dip map-integers ; inline
264 : map-from ( ... seq quot: ( ... elt -- ... newelt ) i -- ... newseq )
265 pick map-from-as ; inline
269 : push-map-if ( ..a elt filter-quot: ( ..a elt -- ..b ? ) map-quot: ( ..a elt -- ..b newelt ) accum -- ..b )
270 [ keep over ] 2dip [ when ] dip rot [ push ] [ 2drop ] if ; inline
272 : (filter-mapper-for) ( filter-quot map-quot length exempler -- filter-mapper accum )
273 new-resizable [ [ push-map-if ] 3curry ] keep ; inline
275 : filter-mapper-for ( filter-quot map-quot exemplar -- filter-mapper accum )
276 [ length ] keep (filter-mapper-for) ; inline
278 : filter-mapper ( filter-quot map-quot -- filter-mapper accum )
279 V{ } filter-mapper-for ; inline
283 : filter-map-as ( ... seq filter-quot: ( ... elt -- ... ? ) map-quot: ( ... elt -- ... newelt ) exemplar -- ... newseq )
285 [ (filter-mapper-for) [ each ] dip ] 2curry dip like ; inline
287 : filter-map ( ... seq filter-quot: ( ... elt -- ... ? ) map-quot: ( ... elt -- ... newelt ) -- ... newseq )
288 pick filter-map-as ; inline
290 : 2map-sum ( ... seq1 seq2 quot: ( ... elt1 elt2 -- ... n ) -- ... n )
291 [ 0 ] 3dip [ dip + ] curry [ rot ] prepose 2each ; inline
293 : 2count ( ... seq1 seq2 quot: ( ... elt1 elt2 -- ... ? ) -- ... n )
294 [ 1 0 ? ] compose 2map-sum ; inline
297 ( ... seq1 seq2 seq3 quot: ( ... elt1 elt2 elt3 -- ... ) i -- ... )
298 [ (3each) ] dip -rot (each-integer) ; inline
301 ( ..a seq1 seq2 seq3 map-quot: ( ..a elt1 elt2 elt3 -- ..b intermediate ) reduce-quot: ( ..b prev intermediate -- ..a next ) -- ..a result )
302 [ [ [ [ first ] tri@ ] 3keep ] dip [ 3dip ] keep ] dip compose 1 3each-from ; inline
304 : round-robin ( seq -- newseq )
306 [ longest length <iota> ] keep
307 [ [ ?nth ] with map ] curry map concat sift
310 : sift-as ( seq exemplar -- newseq )
313 : sift! ( seq -- newseq )
316 : harvest-as ( seq exemplar -- newseq )
317 [ empty? not ] swap filter-as ;
319 : harvest! ( seq -- newseq )
322 : head-as ( seq n exemplar -- seq' )
323 [ head-slice ] [ like ] bi* ; inline
325 : head*-as ( seq n exemplar -- seq' )
326 [ head-slice* ] [ like ] bi* ; inline
328 : tail-as ( seq n exemplar -- seq' )
329 [ tail-slice ] [ like ] bi* ; inline
331 : tail*-as ( seq n exemplar -- seq' )
332 [ tail-slice* ] [ like ] bi* ; inline
334 : trim-as ( ... seq quot: ( ... elt -- ... ? ) exemplar -- ... newseq )
335 [ trim-slice ] [ like ] bi* ; inline
337 : ?trim ( seq quot: ( elt -- ? ) -- seq/newseq )
338 over empty? [ drop ] [
339 over [ first-unsafe ] [ last-unsafe ] bi pick either?
343 : ?trim-head ( seq quot: ( elt -- ? ) -- seq/newseq )
344 over empty? [ drop ] [
345 over first-unsafe over call
346 [ trim-head ] [ drop ] if
349 : ?trim-tail ( seq quot: ( elt -- ? ) -- seq/newseq )
350 over empty? [ drop ] [
351 over last-unsafe over call
352 [ trim-tail ] [ drop ] if
355 : unsurround ( newseq seq2 seq3 -- seq1 )
356 [ ?head drop ] [ ?tail drop ] bi* ;
358 : one? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? )
360 [ 1 + ] 2dip find-from drop not
361 ] [ 3drop f ] if ; inline
363 : map-index! ( ... seq quot: ( ... elt index -- ... newelt ) -- ... seq )
364 over [ [ (each-index) ] dip collect ] keep ; inline
368 : (2each-index) ( seq1 seq2 quot -- n quot' )
369 [ setup-2each [ keep ] curry ] dip compose ; inline
373 : 2each-index ( ... seq1 seq2 quot: ( ... elt1 elt2 index -- ... ) -- ... )
374 (2each-index) each-integer ; inline
376 : 2map-into ( seq1 seq2 quot into -- )
377 [ (2each) ] dip collect ; inline
379 : 2map! ( ... seq1 seq2 quot: ( ... elt1 elt2 -- ... newelt ) -- ... seq1 )
380 pick [ 2map-into ] keep ; inline
382 : 2map-index ( ... seq1 seq2 quot: ( ... elt1 elt2 index -- ... newelt ) -- ... newseq )
383 pick [ (2each-index) ] dip map-integers ; inline
385 TUPLE: evens { seq read-only } ;
389 M: evens length seq>> length 1 + 2/ ; inline
391 M: evens virtual@ [ 2 * ] [ seq>> ] bi* ; inline
393 M: evens virtual-exemplar seq>> ; inline
395 INSTANCE: evens virtual-sequence
397 TUPLE: odds { seq read-only } ;
401 M: odds length seq>> length 2/ ; inline
403 M: odds virtual@ [ 2 * 1 + ] [ seq>> ] bi* ; inline
405 M: odds virtual-exemplar seq>> ; inline
407 INSTANCE: odds virtual-sequence
409 : until-empty ( seq quot -- )
410 [ dup empty? ] swap until drop ; inline
412 : arg-max ( seq -- n )
413 [ supremum ] keep index ;
415 : arg-min ( seq -- n )
416 [ infimum ] keep index ;
420 : push-index-if ( ..a elt i quot: ( ..a elt -- ..b ? ) accum -- ..b )
421 [ dip ] dip rot [ push ] [ 2drop ] if ; inline
425 : arg-where ( ... seq quot: ( ... elt -- ... ? ) -- ... indices )
426 over length <vector> [
427 [ push-index-if ] 2curry each-index
430 : arg-sort ( seq -- indices )
431 zip-index sort-keys values ;
433 : first= ( seq elt -- ? ) [ first ] dip = ; inline
434 : second= ( seq elt -- ? ) [ second ] dip = ; inline
435 : third= ( seq elt -- ? ) [ third ] dip = ; inline
436 : fourth= ( seq elt -- ? ) [ fourth ] dip = ; inline
437 : last= ( seq elt -- ? ) [ last ] dip = ; inline
438 : nth= ( n seq elt -- ? ) [ nth ] dip = ; inline
440 : first? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ first ] dip call ; inline
441 : second? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ second ] dip call ; inline
442 : third? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ third ] dip call ; inline
443 : fourth? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ fourth ] dip call ; inline
444 : last? ( ... seq quot: ( ... elt -- ... ? ) -- ... ? ) [ last ] dip call ; inline
445 : nth? ( ... n seq quot: ( ... elt -- ... ? ) -- ... ? ) [ nth ] dip call ; inline
447 : loop>sequence ( quot: ( ..a -- ..a obj/f ) exemplar -- seq )
448 [ '[ [ @ [ [ , ] when* ] keep ] loop ] ] dip make ; inline
450 : loop>array ( quot: ( ..a -- ..a obj/f ) -- seq )
451 { } loop>sequence ; inline
453 : loop>sequence* ( quot: ( ..a -- ..a obj ? ) exemplar -- seq )
454 [ '[ [ @ [ [ , ] when* ] [ ] bi* ] loop ] ] dip make ; inline
456 : loop>array* ( quot: ( ..a -- ..a obj ? ) -- seq )
457 { } loop>sequence* ; inline
461 : (reverse) ( seq -- newseq )
462 dup [ length ] keep new-sequence
463 [ 0 swap copy-unsafe ] keep reverse! ;
467 : reverse-as ( seq exemplar -- newseq )
468 [ (reverse) ] [ like ] bi* ;
470 : map-product ( ... seq quot: ( ... elt -- ... n ) -- ... n )
471 [ 1 ] 2dip [ dip * ] curry [ swap ] prepose each ; inline
473 : insert-nth! ( elt n seq -- )
474 [ length ] keep ensure swap pick (a,b]
475 over '[ [ 1 + ] keep _ move-unsafe ] each
478 : set-nths ( value indices seq -- )
479 swapd '[ _ swap _ set-nth ] each ; inline
481 : set-nths-unsafe ( value indices seq -- )
482 swapd '[ _ swap _ set-nth-unsafe ] each ; inline
484 : flatten1 ( obj -- seq )
488 [ dup branch? [ % ] [ , ] if ] each
491 ] keep dup branch? [ drop f ] unless make ;
495 : (map-find-index) ( seq quot find-quot -- result i elt )
496 [ [ f ] 2dip [ [ nip ] 2dip call dup ] curry ] dip call
497 [ [ [ drop f ] unless ] keep ] dip ; inline
501 : map-find-index ( ... seq quot: ( ... elt index -- ... result/f ) -- ... result i elt )
502 [ find-index ] (map-find-index) ; inline
504 : filter-length ( seq n -- seq' ) '[ length _ = ] filter ;
506 : all-shortest ( seqs -- seqs' ) dup shortest length filter-length ;
508 : all-longest ( seqs -- seqs' ) dup longest length filter-length ;
510 : remove-first ( obj seq -- seq' )
511 [ index ] keep over [ remove-nth ] [ nip ] if ;
513 : remove-first! ( obj seq -- seq )
514 [ index ] keep over [ remove-nth! ] [ nip ] if ;
516 : remove-last ( obj seq -- seq' )
517 [ last-index ] keep over [ remove-nth ] [ nip ] if ;
519 : remove-last! ( obj seq -- seq )
520 [ last-index ] keep over [ remove-nth! ] [ nip ] if ;
522 : ?first2 ( seq -- first/f second/f )
525 { 1 [ first-unsafe f ] }
526 [ drop first2-unsafe ]
529 : ?first3 ( seq -- first/f second/f third/f )
532 { 1 [ first-unsafe f f ] }
533 { 2 [ first2-unsafe f ] }
534 [ drop first3-unsafe ]
537 : ?first4 ( seq -- first/f second/f third/f fourth/f )
539 { 0 [ drop f f f f ] }
540 { 1 [ first-unsafe f f f ] }
541 { 2 [ first2-unsafe f f ] }
542 { 3 [ first3-unsafe f ] }
543 [ drop first4-unsafe ]
546 : cut-when ( ... seq quot: ( ... elt -- ... ? ) -- ... before after )
547 [ find drop ] keepd swap
548 [ cut ] [ f over like ] if* ; inline
550 : nth* ( n seq -- elt )
551 [ length 1 - swap - ] [ nth ] bi ; inline
553 : each-index-from ( ... seq quot: ( ... elt index -- ... ) i -- ... )
554 -rot (each-index) (each-integer) ; inline
558 : select-by* ( ... seq quot: ( ... elt -- ... x ) compare: ( obj1 obj2 -- ? ) -- ... i elt )
560 [ keep swap ] curry [ dip ] curry
561 [ [ first 0 ] dip call ] 2keep
562 [ 2curry 3dip 5 npick pick ] curry
564 [ [ 3drop ] [ [ 3drop ] 3dip ] if ] compose
565 ] bi* compose 1 each-index-from nip swap ; inline
569 : supremum-by* ( ... seq quot: ( ... elt -- ... x ) -- ... i elt )
570 [ after? ] select-by* ; inline
572 : infimum-by* ( ... seq quot: ( ... elt -- ... x ) -- ... i elt )
573 [ before? ] select-by* ; inline
575 : ?supremum ( seq/f -- elt/f )
577 [ ] [ 2dup and [ max ] [ dupd ? ] if ] map-reduce
580 : ?infimum ( seq/f -- elt/f )
582 [ ] [ 2dup and [ min ] [ dupd ? ] if ] map-reduce
585 : change-last ( seq quot -- )
586 [ drop length 1 - ] [ change-nth ] 2bi ; inline
588 : change-last-unsafe ( seq quot -- )
589 [ drop length 1 - ] [ change-nth-unsafe ] 2bi ; inline
591 : replicate-into ( ... seq quot: ( ... -- ... newelt ) -- ... )
592 over [ length ] 2dip '[ _ dip _ set-nth-unsafe ] each-integer ; inline
594 : count* ( ... seq quot: ( ... elt -- ... ? ) -- ... % )
595 over [ count ] [ length ] bi* / ; inline
597 : find-last-index ( ... seq quot: ( ... elt i -- ... ? ) -- ... i elt )
598 [ [ 1 - ] dip find-last-integer ] (find-index) ; inline
600 : map-find-last-index ( ... seq quot: ( ... elt index -- ... result/f ) -- ... result i elt )
601 [ find-last-index ] (map-find-index) ; inline
603 :: (start-all) ( subseq seq increment -- indices )
605 [ [ subseq seq ] dip subseq-start-from dup ]
606 [ [ increment + ] keep ] produce nip ;
608 : start-all ( subseq seq -- indices )
609 over length (start-all) ; inline
611 : start-all* ( subseq seq -- indices )
612 1 (start-all) ; inline
614 : count-subseq ( subseq seq -- n )
615 start-all length ; inline
617 : count-subseq* ( subseq seq -- n )
618 start-all* length ; inline
620 : map-zip ( quot: ( x -- y ) -- alist )
621 '[ _ keep swap ] map>alist ; inline
623 : map-keys ( assoc quot: ( key -- key' ) -- assoc )
624 '[ _ dip ] assoc-map ; inline
626 : map-values ( assoc quot: ( value -- value' ) -- assoc )
627 '[ swap _ dip swap ] assoc-map ; inline
629 : take-while ( ... seq quot: ( ... elt -- ... ? ) -- head-slice )
630 [ '[ @ not ] find drop ] keepd swap
631 [ dup length ] unless* head-slice ; inline
633 : drop-while ( ... seq quot: ( ... elt -- ... ? ) -- tail-slice )
634 [ '[ @ not ] find drop ] keepd swap
635 [ dup length ] unless* tail-slice ; inline
637 : count-head ( seq quot -- n )
638 [ not ] compose [ find drop ] 2keep drop length or ; inline
640 : count-tail ( seq quot -- n )
641 [ not ] compose [ find-last drop ] 2keep drop
642 length swap [ - 1 - ] when* ; inline
644 :: interleaved-as ( seq glue exemplar -- newseq )
645 seq length dup 1 - + 0 max exemplar new-sequence :> newseq
646 seq [ 2 * newseq set-nth-unsafe ] each-index
647 seq length 1 - [ 2 * 1 + glue swap newseq set-nth-unsafe ] each-integer
650 : interleaved ( seq glue -- newseq )
651 over interleaved-as ;
653 : extract! ( ... seq quot: ( ... elt -- ... ? ) -- ... seq )
654 [ dup ] compose over [ length ] keep new-resizable
655 [ [ push-if ] 2curry reject! ] keep swap like ; inline