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 ! The f object supports the sequence protocol trivially
94 M: f like drop [ f ] when-empty ;
96 INSTANCE: f immutable-sequence
98 ! Integers support the sequence protocol
100 M: integer nth-unsafe drop ;
102 INSTANCE: integer immutable-sequence
106 ! In the future, this will replace integer sequences
107 TUPLE: iota { n integer read-only } ;
109 : iota ( n -- iota ) \ iota boa ; inline
114 M: iota nth-unsafe drop ;
116 INSTANCE: iota immutable-sequence
118 : first-unsafe ( seq -- first )
119 0 swap nth-unsafe ; inline
121 : first2-unsafe ( seq -- first second )
122 [ first-unsafe ] [ 1 swap nth-unsafe ] bi ; inline
124 : first3-unsafe ( seq -- first second third )
125 [ first2-unsafe ] [ 2 swap nth-unsafe ] bi ; inline
127 : first4-unsafe ( seq -- first second third fourth )
128 [ first3-unsafe ] [ 3 swap nth-unsafe ] bi ; inline
130 : exchange-unsafe ( m n seq -- )
131 [ [ nth-unsafe ] curry bi@ ]
132 [ [ set-nth-unsafe ] curry bi@ ] 3bi ; inline
134 : (head) ( seq n -- from to seq ) [ 0 ] 2dip swap ; inline
136 : (tail) ( seq n -- from to seq ) swap [ length ] keep ; inline
138 : from-end ( seq n -- seq n' ) [ dup length ] dip - ; inline
140 : (1sequence) ( obj seq -- seq )
141 [ 0 swap set-nth-unsafe ] keep ; inline
143 : (2sequence) ( obj1 obj2 seq -- seq )
144 [ 1 swap set-nth-unsafe ] keep
147 : (3sequence) ( obj1 obj2 obj3 seq -- seq )
148 [ 2 swap set-nth-unsafe ] keep
151 : (4sequence) ( obj1 obj2 obj3 obj4 seq -- seq )
152 [ 3 swap set-nth-unsafe ] keep
157 : 1sequence ( obj exemplar -- seq )
158 1 swap [ (1sequence) ] new-like ; inline
160 : 2sequence ( obj1 obj2 exemplar -- seq )
161 2 swap [ (2sequence) ] new-like ; inline
163 : 3sequence ( obj1 obj2 obj3 exemplar -- seq )
164 3 swap [ (3sequence) ] new-like ; inline
166 : 4sequence ( obj1 obj2 obj3 obj4 exemplar -- seq )
167 4 swap [ (4sequence) ] new-like ; inline
169 : first2 ( seq -- first second )
170 1 swap bounds-check nip first2-unsafe ; flushable
172 : first3 ( seq -- first second third )
173 2 swap bounds-check nip first3-unsafe ; flushable
175 : first4 ( seq -- first second third fourth )
176 3 swap bounds-check nip first4-unsafe ; flushable
178 : ?nth ( n seq -- elt/f )
179 2dup bounds-check? [ nth-unsafe ] [ 2drop f ] if ; flushable
181 MIXIN: virtual-sequence
182 GENERIC: virtual-seq ( seq -- seq' )
183 GENERIC: virtual@ ( n seq -- n' seq' )
185 M: virtual-sequence nth virtual@ nth ;
186 M: virtual-sequence set-nth virtual@ set-nth ;
187 M: virtual-sequence nth-unsafe virtual@ nth-unsafe ;
188 M: virtual-sequence set-nth-unsafe virtual@ set-nth-unsafe ;
189 M: virtual-sequence like virtual-seq like ;
190 M: virtual-sequence new-sequence virtual-seq new-sequence ;
192 INSTANCE: virtual-sequence sequence
194 ! A reversal of an underlying sequence.
195 TUPLE: reversed { seq read-only } ;
197 C: <reversed> reversed
199 M: reversed virtual-seq seq>> ;
201 M: reversed virtual@ seq>> [ length swap - 1- ] keep ;
203 M: reversed length seq>> length ;
205 INSTANCE: reversed virtual-sequence
207 ! A slice of another sequence.
213 : collapse-slice ( m n slice -- m' n' seq )
214 [ from>> ] [ seq>> ] bi [ [ + ] curry bi@ ] dip ; inline
216 ERROR: slice-error from to seq reason ;
218 : check-slice ( from to seq -- from to seq )
219 pick 0 < [ "start < 0" slice-error ] when
220 dup length pick < [ "end > sequence" slice-error ] when
221 2over > [ "start > end" slice-error ] when ; inline
223 : <slice> ( from to seq -- slice )
224 dup slice? [ collapse-slice ] when
228 M: slice virtual-seq seq>> ;
230 M: slice virtual@ [ from>> + ] [ seq>> ] bi ;
232 M: slice length [ to>> ] [ from>> ] bi - ;
234 : short ( seq n -- seq n' ) over length min ; inline
236 : head-slice ( seq n -- slice ) (head) <slice> ; inline
238 : tail-slice ( seq n -- slice ) (tail) <slice> ; inline
240 : rest-slice ( seq -- slice ) 1 tail-slice ; inline
242 : head-slice* ( seq n -- slice ) from-end head-slice ; inline
244 : tail-slice* ( seq n -- slice ) from-end tail-slice ; inline
246 : but-last-slice ( seq -- slice ) 1 head-slice* ; inline
248 INSTANCE: slice virtual-sequence
250 ! One element repeated many times
251 TUPLE: repetition { len read-only } { elt read-only } ;
253 C: <repetition> repetition
255 M: repetition length len>> ;
256 M: repetition nth-unsafe nip elt>> ;
258 INSTANCE: repetition immutable-sequence
262 : check-length ( n -- n )
264 dup integer? [ "length not an integer" throw ] unless ; inline
266 : ((copy)) ( dst i src j n -- dst i src j n )
268 + swap nth-unsafe -roll [
269 + swap set-nth-unsafe
273 : (copy) ( dst i src j n -- dst )
274 dup 0 <= [ 2drop 2drop ] [ 1- ((copy)) (copy) ] if ;
277 : prepare-subseq ( from to seq -- dst i src j n )
278 #! The check-length call forces partial dispatch
279 [ [ swap - ] dip new-sequence dup 0 ] 3keep
280 -rot drop roll length check-length ; inline
282 : check-copy ( src n dst -- )
283 over 0 < [ bounds-error ] when
284 [ swap length + ] dip lengthen ; inline
288 : subseq ( from to seq -- subseq )
289 [ check-slice prepare-subseq (copy) ] keep like ;
291 : head ( seq n -- headseq ) (head) subseq ;
293 : tail ( seq n -- tailseq ) (tail) subseq ;
295 : rest ( seq -- tailseq ) 1 tail ;
297 : head* ( seq n -- headseq ) from-end head ;
299 : tail* ( seq n -- tailseq ) from-end tail ;
301 : but-last ( seq -- headseq ) 1 head* ;
303 : copy ( src i dst -- )
304 #! The check-length call forces partial dispatch
305 pick length check-length [ 3dup check-copy spin 0 ] dip
308 M: sequence clone-like
309 [ dup length ] dip new-sequence [ 0 swap copy ] keep ;
311 M: immutable-sequence clone-like like ;
313 : push-all ( src dest -- ) [ length ] [ copy ] bi ;
317 : (append) ( seq1 seq2 accum -- accum )
318 [ [ over length ] dip copy ]
324 : append-as ( seq1 seq2 exemplar -- newseq )
325 [ over length over length + ] dip
326 [ (append) ] new-like ; inline
328 : 3append-as ( seq1 seq2 seq3 exemplar -- newseq )
329 [ pick length pick length pick length + + ] dip [
330 [ [ pick length pick length + ] dip copy ]
334 : append ( seq1 seq2 -- newseq ) over append-as ;
336 : prepend ( seq1 seq2 -- newseq ) swap append ; inline
338 : 3append ( seq1 seq2 seq3 -- newseq ) pick 3append-as ;
340 : surround ( seq1 seq2 seq3 -- newseq ) swapd 3append ; inline
342 : glue ( seq1 seq2 seq3 -- newseq ) swap 3append ; inline
344 : change-nth ( i seq quot -- )
345 [ [ nth ] dip call ] 3keep drop set-nth ; inline
347 : min-length ( seq1 seq2 -- n ) [ length ] bi@ min ; inline
349 : max-length ( seq1 seq2 -- n ) [ length ] bi@ max ; inline
353 : (each) ( seq quot -- n quot' )
354 [ [ length ] keep [ nth-unsafe ] curry ] dip compose ; inline
356 : (collect) ( quot into -- quot' )
357 [ [ keep ] dip set-nth-unsafe ] 2curry ; inline
359 : collect ( n quot into -- )
360 (collect) each-integer ; inline
362 : map-into ( seq quot into -- )
363 [ (each) ] dip collect ; inline
365 : 2nth-unsafe ( n seq1 seq2 -- elt1 elt2 )
366 [ nth-unsafe ] bi-curry@ bi ; inline
368 : (2each) ( seq1 seq2 quot -- n quot' )
371 [ 2nth-unsafe ] 2curry
372 ] dip compose ; inline
374 : 3nth-unsafe ( n seq1 seq2 seq3 -- elt1 elt2 elt3 )
375 [ nth-unsafe ] tri-curry@ tri ; inline
377 : (3each) ( seq1 seq2 seq3 quot -- n quot' )
379 [ [ length ] tri@ min min ]
380 [ [ 3nth-unsafe ] 3curry ] 3bi
381 ] dip compose ; inline
383 : finish-find ( i seq -- i elt )
384 over [ dupd nth-unsafe ] [ drop f ] if ; inline
386 : (find) ( seq quot quot' -- i elt )
387 pick [ [ (each) ] dip call ] dip finish-find ; inline
389 : (find-from) ( n seq quot quot' -- i elt )
390 [ 2dup bounds-check? ] 2dip
397 : each ( seq quot -- )
398 (each) each-integer ; inline
400 : reduce ( seq identity quot -- result )
403 : map-as ( seq quot exemplar -- newseq )
404 [ over length ] dip [ [ map-into ] keep ] new-like ; inline
406 : map ( seq quot -- newseq )
409 : replicate ( seq quot -- newseq )
410 [ drop ] prepose map ; inline
412 : replicate-as ( seq quot exemplar -- newseq )
413 [ [ drop ] prepose ] dip map-as ; inline
415 : change-each ( seq quot -- )
416 over map-into ; inline
418 : accumulate ( seq identity quot -- final newseq )
419 swapd [ [ call ] [ 2drop ] 3bi ] curry map ; inline
421 : 2each ( seq1 seq2 quot -- )
422 (2each) each-integer ; inline
424 : 2reverse-each ( seq1 seq2 quot -- )
425 [ [ <reversed> ] bi@ ] dip 2each ; inline
427 : 2reduce ( seq1 seq2 identity quot -- result )
428 [ -rot ] dip 2each ; inline
430 : 2map-as ( seq1 seq2 quot exemplar -- newseq )
431 [ (2each) ] dip map-as ; inline
433 : 2map ( seq1 seq2 quot -- newseq )
434 pick 2map-as ; inline
436 : 2all? ( seq1 seq2 quot -- ? )
437 (2each) all-integers? ; inline
439 : 3each ( seq1 seq2 seq3 quot -- )
440 (3each) each ; inline
442 : 3map-as ( seq1 seq2 seq3 quot exemplar -- newseq )
443 [ (3each) ] dip map-as ; inline
445 : 3map ( seq1 seq2 seq3 quot -- newseq )
446 [ pick ] dip swap 3map-as ; inline
448 : find-from ( n seq quot -- i elt )
449 [ (find-integer) ] (find-from) ; inline
451 : find ( seq quot -- i elt )
452 [ find-integer ] (find) ; inline
454 : find-last-from ( n seq quot -- i elt )
455 [ nip find-last-integer ] (find-from) ; inline
457 : find-last ( seq quot -- i elt )
458 [ [ 1- ] dip find-last-integer ] (find) ; inline
460 : all? ( seq quot -- ? )
461 (each) all-integers? ; inline
463 : push-if ( elt quot accum -- )
464 [ keep ] dip rot [ push ] [ 2drop ] if ; inline
466 : pusher ( quot -- quot accum )
467 V{ } clone [ [ push-if ] 2curry ] keep ; inline
469 : filter ( seq quot -- subseq )
470 over [ pusher [ each ] dip ] dip like ; inline
472 : push-either ( elt quot accum1 accum2 -- )
473 [ keep swap ] 2dip ? push ; inline
475 : 2pusher ( quot -- quot accum1 accum2 )
476 V{ } clone V{ } clone [ [ push-either ] 3curry ] 2keep ; inline
478 : partition ( seq quot -- trueseq falseseq )
479 over [ 2pusher [ each ] 2dip ] dip [ like ] curry bi@ ; inline
481 : accumulator ( quot -- quot' vec )
482 V{ } clone [ [ push ] curry compose ] keep ; inline
484 : produce-as ( pred quot tail exemplar -- seq )
485 [ swap accumulator [ swap while ] dip ] dip like ; inline
487 : produce ( pred quot tail -- seq )
488 { } produce-as ; inline
490 : follow ( obj quot -- seq )
491 [ dup ] swap [ keep ] curry [ ] produce nip ; inline
493 : prepare-index ( seq quot -- seq n quot )
494 [ dup length ] dip ; inline
496 : each-index ( seq quot -- )
497 prepare-index 2each ; inline
499 : interleave ( seq between quot -- )
500 swap [ drop ] [ [ 2dip call ] 2curry ] 2bi
501 [ [ 0 = ] 2dip if ] 2curry
504 : map-index ( seq quot -- )
505 prepare-index 2map ; inline
507 : reduce-index ( seq identity quot -- )
508 swapd each-index ; inline
510 : index ( obj seq -- n )
511 [ = ] with find drop ;
513 : index-from ( obj i seq -- n )
514 rot [ = ] curry find-from drop ;
516 : last-index ( obj seq -- n )
517 [ = ] with find-last drop ;
519 : last-index-from ( obj i seq -- n )
520 rot [ = ] curry find-last-from drop ;
522 : (indices) ( elt i obj accum -- )
523 [ swap [ = ] dip ] dip [ push ] 2curry when ; inline
525 : indices ( obj seq -- indices )
527 [ [ (indices) ] 2curry each-index ] keep ;
529 : nths ( indices seq -- seq' )
532 : any? ( seq quot -- ? )
533 find drop >boolean ; inline
535 : member? ( elt seq -- ? )
538 : memq? ( elt seq -- ? )
541 : remove ( elt seq -- newseq )
542 [ = not ] with filter ;
544 : remq ( elt seq -- newseq )
545 [ eq? not ] with filter ;
547 : sift ( seq -- newseq )
550 : harvest ( seq -- newseq )
551 [ empty? not ] filter ;
553 : mismatch ( seq1 seq2 -- i )
555 [ 2nth-unsafe = not ] 2curry
560 [ -rot 2nth-unsafe <=> ] [ [ length ] compare ] if* ;
562 : sequence= ( seq1 seq2 -- ? )
563 2dup [ length ] bi@ =
564 [ mismatch not ] [ 2drop f ] if ; inline
566 : sequence-hashcode-step ( oldhash newpart -- newhash )
568 [ -2 fixnum-shift-fast ] [ 5 fixnum-shift-fast ] bi
569 fixnum+fast fixnum+fast
570 ] keep fixnum-bitxor ; inline
572 : sequence-hashcode ( n seq -- x )
573 [ 0 ] 2dip [ hashcode* sequence-hashcode-step ] with each ; inline
575 M: reversed equal? over reversed? [ sequence= ] [ 2drop f ] if ;
577 M: slice equal? over slice? [ sequence= ] [ 2drop f ] if ;
579 : move ( to from seq -- )
581 [ 3drop ] [ [ nth swap ] [ set-nth ] bi ] if ; inline
585 : (filter-here) ( quot: ( elt -- ? ) store scan seq -- )
588 [ nth-unsafe pick call [ 1+ ] when ] 2keep
591 ] [ nip set-length drop ] if ; inline recursive
595 : filter-here ( seq quot -- )
596 swap [ 0 0 ] dip (filter-here) ; inline
598 : delete ( elt seq -- )
599 [ = not ] with filter-here ;
601 : delq ( elt seq -- )
602 [ eq? not ] with filter-here ;
604 : prefix ( seq elt -- newseq )
605 over [ over length 1+ ] dip [
606 [ 0 swap set-nth-unsafe ] keep
610 : suffix ( seq elt -- newseq )
611 over [ over length 1+ ] dip [
612 [ [ over length ] dip set-nth-unsafe ] keep
616 : peek ( seq -- elt ) [ length 1- ] [ nth ] bi ;
618 : pop* ( seq -- ) [ length 1- ] [ shorten ] bi ;
622 : move-backward ( shift from to seq -- )
626 [ [ 2over + pick ] dip move [ 1+ ] dip ] keep
630 : move-forward ( shift from to seq -- )
634 [ [ pick [ dup dup ] dip + swap ] dip move 1- ] keep
638 : (open-slice) ( shift from to seq ? -- )
640 [ [ 1- ] bi@ ] dip move-forward
642 [ over - ] 2dip move-backward
645 : open-slice ( shift from seq -- )
649 pick over length + over
650 [ pick 0 > [ [ length ] keep ] dip (open-slice) ] 2dip
656 : delete-slice ( from to seq -- )
657 check-slice [ over [ - ] dip ] dip open-slice ;
659 : delete-nth ( n seq -- )
660 [ dup 1+ ] dip delete-slice ;
662 : snip ( from to seq -- head tail )
663 [ swap head ] [ swap tail ] bi-curry bi* ; inline
665 : snip-slice ( from to seq -- head tail )
666 [ swap head-slice ] [ swap tail-slice ] bi-curry bi* ; inline
668 : replace-slice ( new from to seq -- seq' )
669 snip-slice surround ;
671 : remove-nth ( n seq -- seq' )
672 [ [ { } ] dip dup 1+ ] dip replace-slice ;
675 [ length 1- ] [ [ nth ] [ shorten ] 2bi ] bi ;
677 : exchange ( m n seq -- )
678 [ nip bounds-check 2drop ]
679 [ bounds-check 3drop ]
683 : reverse-here ( seq -- )
684 [ length 2/ ] [ length ] [ ] tri
685 [ [ over - 1- ] dip exchange-unsafe ] 2curry each ;
687 : reverse ( seq -- newseq )
689 dup [ length ] keep new-sequence
691 [ reverse-here ] keep
694 : sum-lengths ( seq -- n )
695 0 [ length + ] reduce ;
697 : concat ( seq -- newseq )
700 [ first new-resizable ] keep
701 [ [ over push-all ] each ] keep
707 : joined-length ( seq glue -- n )
708 [ [ sum-lengths ] [ length 1 [-] ] bi ] dip length * + ;
712 : join ( seq glue -- newseq )
714 2dup joined-length over new-resizable [
715 [ [ push-all ] 2curry ] [ [ nip push-all ] 2curry ] 2bi
720 : padding ( seq n elt quot -- newseq )
722 [ over length [-] dup 0 = [ drop ] ] dip
723 [ <repetition> ] curry
724 ] dip compose if ; inline
726 : pad-head ( seq n elt -- padded )
727 [ swap dup append-as ] padding ;
729 : pad-tail ( seq n elt -- padded )
732 : shorter? ( seq1 seq2 -- ? ) [ length ] bi@ < ;
734 : head? ( seq begin -- ? )
738 [ nip ] [ length head-slice ] 2bi sequence=
741 : tail? ( seq end -- ? )
745 [ nip ] [ length tail-slice* ] 2bi sequence=
748 : cut-slice ( seq n -- before-slice after-slice )
749 [ head-slice ] [ tail-slice ] 2bi ;
751 : insert-nth ( elt n seq -- seq' )
752 swap cut-slice [ swap suffix ] dip append ;
754 : midpoint@ ( seq -- n ) length 2/ ; inline
756 : halves ( seq -- first-slice second-slice )
757 dup midpoint@ cut-slice ;
759 : binary-reduce ( seq start quot: ( elt1 elt2 -- newelt ) -- value )
760 #! We can't use case here since combinators depends on
762 pick length dup 0 3 between? [
766 [ [ drop first2 ] dip call ]
767 [ [ drop first3 ] dip bi@ ]
772 [ [ binary-reduce ] 2curry bi@ ] keep
774 ] if ; inline recursive
776 : cut ( seq n -- before after )
777 [ head ] [ tail ] 2bi ;
779 : cut* ( seq n -- before after )
780 [ head* ] [ tail* ] 2bi ;
784 : (start) ( subseq seq n -- subseq seq ? )
786 [ 3dup ] dip [ + swap nth-unsafe ] keep rot nth-unsafe =
791 : start* ( subseq seq n -- i )
792 pick length pick length swap - 1+
793 [ (start) ] find-from
796 : start ( subseq seq -- i ) 0 start* ; inline
798 : subseq? ( subseq seq -- ? ) start >boolean ;
800 : drop-prefix ( seq1 seq2 -- slice1 slice2 )
801 2dup mismatch [ 2dup min-length ] unless*
802 [ tail-slice ] curry bi@ ;
804 : unclip ( seq -- rest first )
805 [ rest ] [ first-unsafe ] bi ;
807 : unclip-last ( seq -- butlast last )
808 [ but-last ] [ peek ] bi ;
810 : unclip-slice ( seq -- rest-slice first )
811 [ rest-slice ] [ first-unsafe ] bi ; inline
813 : 2unclip-slice ( seq1 seq2 -- rest-slice1 rest-slice2 first1 first2 )
814 [ unclip-slice ] bi@ swapd ; inline
816 : map-reduce ( seq map-quot reduce-quot -- result )
817 [ [ unclip-slice ] dip [ call ] keep ] dip
818 compose reduce ; inline
820 : 2map-reduce ( seq1 seq2 map-quot reduce-quot -- result )
821 [ [ 2unclip-slice ] dip [ call ] keep ] dip
822 compose 2reduce ; inline
824 : unclip-last-slice ( seq -- butlast-slice last )
825 [ but-last-slice ] [ peek ] bi ; inline
827 : <flat-slice> ( seq -- slice )
828 dup slice? [ { } like ] when
829 [ drop 0 ] [ length ] [ ] tri <slice> ;
834 : (trim-head) ( seq quot -- seq n )
835 over [ [ not ] compose find drop ] dip
836 [ length or ] keep swap ; inline
838 : (trim-tail) ( seq quot -- seq n )
839 over [ [ not ] compose find-last drop ?1+ ] dip
844 : trim-head-slice ( seq quot -- slice )
845 (trim-head) tail-slice ; inline
847 : trim-head ( seq quot -- newseq )
848 (trim-head) tail ; inline
850 : trim-tail-slice ( seq quot -- slice )
851 (trim-tail) head-slice ; inline
853 : trim-tail ( seq quot -- newseq )
854 (trim-tail) head ; inline
856 : trim-slice ( seq quot -- slice )
857 [ trim-head-slice ] [ trim-tail-slice ] bi ; inline
859 : trim ( seq quot -- newseq )
860 [ trim-slice ] [ drop ] 2bi like ; inline
862 : sum ( seq -- n ) 0 [ + ] binary-reduce ;
864 : product ( seq -- n ) 1 [ * ] binary-reduce ;
866 : infimum ( seq -- n ) [ ] [ min ] map-reduce ;
868 : supremum ( seq -- n ) [ ] [ max ] map-reduce ;
870 : sigma ( seq quot -- n )
871 [ 0 ] 2dip [ dip + ] curry [ swap ] prepose each ; inline
873 : count ( seq quot -- n ) [ 1 0 ? ] compose sigma ; inline
875 ! We hand-optimize flip to such a degree because type hints
876 ! cannot express that an array is an array of arrays yet, and
877 ! this word happens to be performance-critical since the compiler
878 ! itself uses it. Optimizing it like this reduced compile time.
881 : generic-flip ( matrix -- newmatrix )
882 [ dup first length [ length min ] reduce ] keep
883 [ [ nth-unsafe ] with { } map-as ] curry { } map-as ; inline
887 : array-length ( array -- len )
888 { array } declare length>> ; inline
890 : array-flip ( matrix -- newmatrix )
892 [ dup first array-length [ array-length min ] reduce ] keep
893 [ [ array-nth ] with { } map-as ] curry { } map-as ;
897 : flip ( matrix -- newmatrix )
901 [ array-flip ] [ generic-flip ] if
902 ] [ generic-flip ] if