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 locals 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 quot -- n quot' )
362 [ [ length ] keep [ nth-unsafe ] curry ] dip compose ; inline
364 : (collect) ( quot into -- quot' )
365 [ [ keep ] dip set-nth-unsafe ] 2curry ; inline
367 : collect ( n quot into -- )
368 (collect) each-integer ; inline
370 : map-into ( seq quot into -- )
371 [ (each) ] dip collect ; inline
373 : 2nth-unsafe ( n seq1 seq2 -- elt1 elt2 )
374 [ nth-unsafe ] bi-curry@ bi ; inline
376 : (2each) ( seq1 seq2 quot -- n quot' )
379 [ 2nth-unsafe ] 2curry
380 ] dip compose ; inline
382 : 3nth-unsafe ( n seq1 seq2 seq3 -- elt1 elt2 elt3 )
383 [ nth-unsafe ] tri-curry@ tri ; inline
385 : (3each) ( seq1 seq2 seq3 quot -- n quot' )
387 [ [ length ] tri@ min min ]
388 [ [ 3nth-unsafe ] 3curry ] 3bi
389 ] dip compose ; inline
391 : finish-find ( i seq -- i elt )
392 over [ dupd nth-unsafe ] [ drop f ] if ; inline
394 : (find) ( seq quot quot' -- i elt )
395 pick [ [ (each) ] dip call ] dip finish-find ; inline
397 : (find-from) ( n seq quot quot' -- i elt )
398 [ 2dup bounds-check? ] 2dip
405 : each ( seq quot -- )
406 (each) each-integer ; inline
408 : reduce ( seq identity quot -- result )
411 : map-as ( seq quot exemplar -- newseq )
412 [ over length ] dip [ [ map-into ] keep ] new-like ; inline
414 : map ( seq quot -- newseq )
417 : replicate ( seq quot -- newseq )
418 [ drop ] prepose map ; inline
420 : replicate-as ( seq quot exemplar -- newseq )
421 [ [ drop ] prepose ] dip map-as ; inline
423 : change-each ( seq quot -- )
424 over map-into ; inline
426 : accumulate ( seq identity quot -- final newseq )
427 swapd [ [ call ] [ 2drop ] 3bi ] curry { } map-as ; inline
429 : 2each ( seq1 seq2 quot -- )
430 (2each) each-integer ; inline
432 : 2reverse-each ( seq1 seq2 quot -- )
433 [ [ <reversed> ] bi@ ] dip 2each ; inline
435 : 2reduce ( seq1 seq2 identity quot -- result )
436 [ -rot ] dip 2each ; inline
438 : 2map-as ( seq1 seq2 quot exemplar -- newseq )
439 [ (2each) ] dip map-as ; inline
441 : 2map ( seq1 seq2 quot -- newseq )
442 pick 2map-as ; inline
444 : 2all? ( seq1 seq2 quot -- ? )
445 (2each) all-integers? ; inline
447 : 3each ( seq1 seq2 seq3 quot -- )
448 (3each) each ; inline
450 : 3map-as ( seq1 seq2 seq3 quot exemplar -- newseq )
451 [ (3each) ] dip map-as ; inline
453 : 3map ( seq1 seq2 seq3 quot -- newseq )
454 [ pick ] dip swap 3map-as ; inline
456 : find-from ( n seq quot -- i elt )
457 [ (find-integer) ] (find-from) ; inline
459 : find ( seq quot -- i elt )
460 [ find-integer ] (find) ; inline
462 : find-last-from ( n seq quot -- i elt )
463 [ nip find-last-integer ] (find-from) ; inline
465 : find-last ( seq quot -- i elt )
466 [ [ 1 - ] dip find-last-integer ] (find) ; inline
468 : all? ( seq quot -- ? )
469 (each) all-integers? ; inline
471 : push-if ( elt quot accum -- )
472 [ keep ] dip rot [ push ] [ 2drop ] if ; inline
474 : pusher ( quot -- quot accum )
475 V{ } clone [ [ push-if ] 2curry ] keep ; inline
477 : filter ( seq quot -- subseq )
478 over [ pusher [ each ] dip ] dip like ; inline
480 : push-either ( elt quot accum1 accum2 -- )
481 [ keep swap ] 2dip ? push ; inline
483 : 2pusher ( quot -- quot accum1 accum2 )
484 V{ } clone V{ } clone [ [ push-either ] 3curry ] 2keep ; inline
486 : partition ( seq quot -- trueseq falseseq )
487 over [ 2pusher [ each ] 2dip ] dip [ like ] curry bi@ ; inline
489 : accumulator ( quot -- quot' vec )
490 V{ } clone [ [ push ] curry compose ] keep ; inline
492 : produce-as ( pred quot exemplar -- seq )
493 [ accumulator [ while ] dip ] dip like ; inline
495 : produce ( pred quot -- seq )
496 { } produce-as ; inline
498 : follow ( obj quot -- seq )
499 [ dup ] swap [ keep ] curry produce nip ; inline
501 : prepare-index ( seq quot -- seq n quot )
502 [ dup length ] dip ; inline
504 : each-index ( seq quot -- )
505 prepare-index 2each ; inline
507 : interleave ( seq between quot -- )
508 swap [ drop ] [ [ 2dip call ] 2curry ] 2bi
509 [ [ 0 = ] 2dip if ] 2curry
512 : map-index ( seq quot -- newseq )
513 prepare-index 2map ; inline
515 : reduce-index ( seq identity quot -- )
516 swapd each-index ; inline
518 : index ( obj seq -- n )
519 [ = ] with find drop ;
521 : index-from ( obj i seq -- n )
522 rot [ = ] curry find-from drop ;
524 : last-index ( obj seq -- n )
525 [ = ] with find-last drop ;
527 : last-index-from ( obj i seq -- n )
528 rot [ = ] curry find-last-from drop ;
530 : (indices) ( elt i obj accum -- )
531 [ swap [ = ] dip ] dip [ push ] 2curry when ; inline
533 : indices ( obj seq -- indices )
535 [ [ (indices) ] 2curry each-index ] keep ;
537 : nths ( indices seq -- seq' )
540 : any? ( seq quot -- ? )
541 find drop >boolean ; inline
543 : member? ( elt seq -- ? )
546 : memq? ( elt seq -- ? )
549 : remove ( elt seq -- newseq )
550 [ = not ] with filter ;
552 : remq ( elt seq -- newseq )
553 [ eq? not ] with filter ;
555 : sift ( seq -- newseq )
558 : harvest ( seq -- newseq )
559 [ empty? not ] filter ;
561 : mismatch ( seq1 seq2 -- i )
562 [ min-length iota ] 2keep
563 [ 2nth-unsafe = not ] 2curry
568 [ -rot 2nth-unsafe <=> ] [ [ length ] compare ] if* ;
570 : sequence= ( seq1 seq2 -- ? )
571 2dup [ length ] bi@ =
572 [ mismatch not ] [ 2drop f ] if ; inline
574 ERROR: assert-sequence got expected ;
576 : assert-sequence= ( a b -- )
577 2dup sequence= [ 2drop ] [ assert-sequence ] if ;
579 : sequence-hashcode-step ( oldhash newpart -- newhash )
581 [ -2 fixnum-shift-fast ] [ 5 fixnum-shift-fast ] bi
582 fixnum+fast fixnum+fast
583 ] keep fixnum-bitxor ; inline
585 : sequence-hashcode ( n seq -- x )
586 [ 0 ] 2dip [ hashcode* sequence-hashcode-step ] with each ; inline
588 M: reversed equal? over reversed? [ sequence= ] [ 2drop f ] if ;
590 M: slice equal? over slice? [ sequence= ] [ 2drop f ] if ;
592 : move ( to from seq -- )
594 [ 3drop ] [ [ nth swap ] [ set-nth ] bi ] if ; inline
598 : (filter-here) ( quot: ( elt -- ? ) store scan seq -- )
601 [ nth-unsafe pick call [ 1 + ] when ] 2keep
604 ] [ nip set-length drop ] if ; inline recursive
608 : filter-here ( seq quot -- )
609 swap [ 0 0 ] dip (filter-here) ; inline
611 : delete ( elt seq -- )
612 [ = not ] with filter-here ;
614 : delq ( elt seq -- )
615 [ eq? not ] with filter-here ;
617 : prefix ( seq elt -- newseq )
618 over [ over length 1 + ] dip [
619 [ 0 swap set-nth-unsafe ] keep
623 : suffix ( seq elt -- newseq )
624 over [ over length 1 + ] dip [
625 [ [ over length ] dip set-nth-unsafe ] keep
629 : last ( seq -- elt ) [ length 1 - ] [ nth ] bi ;
631 : pop* ( seq -- ) [ length 1 - ] [ shorten ] bi ;
635 : move-backward ( shift from to seq -- )
639 [ [ 2over + pick ] dip move [ 1 + ] dip ] keep
643 : move-forward ( shift from to seq -- )
647 [ [ pick [ dup dup ] dip + swap ] dip move 1 - ] keep
651 : (open-slice) ( shift from to seq ? -- )
653 [ [ 1 - ] bi@ ] dip move-forward
655 [ over - ] 2dip move-backward
658 : open-slice ( shift from seq -- )
662 pick over length + over
663 [ pick 0 > [ [ length ] keep ] dip (open-slice) ] 2dip
669 : delete-slice ( from to seq -- )
670 check-slice [ over [ - ] dip ] dip open-slice ;
672 : delete-nth ( n seq -- )
673 [ dup 1 + ] dip delete-slice ;
675 : snip ( from to seq -- head tail )
676 [ swap head ] [ swap tail ] bi-curry bi* ; inline
678 : snip-slice ( from to seq -- head tail )
679 [ swap head-slice ] [ swap tail-slice ] bi-curry bi* ; inline
681 : replace-slice ( new from to seq -- seq' )
682 snip-slice surround ;
684 : remove-nth ( n seq -- seq' )
685 [ [ { } ] dip dup 1 + ] dip replace-slice ;
688 [ length 1 - ] [ [ nth ] [ shorten ] 2bi ] bi ;
690 : exchange ( m n seq -- )
691 [ nip bounds-check 2drop ]
692 [ bounds-check 3drop ]
696 : reverse-here ( seq -- )
697 [ length 2/ ] [ length ] [ ] tri
698 [ [ over - 1 - ] dip exchange-unsafe ] 2curry each ;
700 : reverse ( seq -- newseq )
702 dup [ length ] keep new-sequence
704 [ reverse-here ] keep
707 : sum-lengths ( seq -- n )
708 0 [ length + ] reduce ;
710 : concat-as ( seq exemplar -- newseq )
712 [ sum-lengths over new-resizable ] keep
713 [ over push-all ] each
714 ] if-empty swap like ;
716 : concat ( seq -- newseq )
717 [ { } ] [ dup first concat-as ] if-empty ;
721 : joined-length ( seq glue -- n )
722 [ [ sum-lengths ] [ length 1 [-] ] bi ] dip length * + ;
726 : join ( seq glue -- newseq )
727 dup empty? [ concat-as ] [
729 2dup joined-length over new-resizable [
730 [ [ push-all ] 2curry ] [ [ nip push-all ] 2curry ] 2bi
736 : padding ( seq n elt quot -- newseq )
738 [ over length [-] dup 0 = [ drop ] ] dip
739 [ <repetition> ] curry
740 ] dip compose if ; inline
742 : pad-head ( seq n elt -- padded )
743 [ swap dup append-as ] padding ;
745 : pad-tail ( seq n elt -- padded )
748 : shorter? ( seq1 seq2 -- ? ) [ length ] bi@ < ;
750 : head? ( seq begin -- ? )
754 [ nip ] [ length head-slice ] 2bi sequence=
757 : tail? ( seq end -- ? )
761 [ nip ] [ length tail-slice* ] 2bi sequence=
764 : cut-slice ( seq n -- before-slice after-slice )
765 [ head-slice ] [ tail-slice ] 2bi ;
767 : insert-nth ( elt n seq -- seq' )
768 swap cut-slice [ swap suffix ] dip append ;
770 : midpoint@ ( seq -- n ) length 2/ ; inline
772 : halves ( seq -- first-slice second-slice )
773 dup midpoint@ cut-slice ;
775 : binary-reduce ( seq start quot: ( elt1 elt2 -- newelt ) -- value )
776 #! We can't use case here since combinators depends on
778 pick length dup 0 3 between? [
782 [ [ drop first2 ] dip call ]
783 [ [ drop first3 ] dip bi@ ]
788 [ [ binary-reduce ] 2curry bi@ ] keep
790 ] if ; inline recursive
792 : cut ( seq n -- before after )
793 [ head ] [ tail ] 2bi ;
795 : cut* ( seq n -- before after )
796 [ head* ] [ tail* ] 2bi ;
800 : (start) ( subseq seq n -- subseq seq ? )
802 [ 3dup ] dip [ + swap nth-unsafe ] keep rot nth-unsafe =
807 : start* ( subseq seq n -- i )
808 pick length pick length swap - 1 +
809 [ (start) ] find-from
812 : start ( subseq seq -- i ) 0 start* ; inline
814 : subseq? ( subseq seq -- ? ) start >boolean ;
816 : drop-prefix ( seq1 seq2 -- slice1 slice2 )
817 2dup mismatch [ 2dup min-length ] unless*
818 [ tail-slice ] curry bi@ ;
820 : unclip ( seq -- rest first )
821 [ rest ] [ first-unsafe ] bi ;
823 : unclip-last ( seq -- butlast last )
824 [ but-last ] [ last ] bi ;
826 : unclip-slice ( seq -- rest-slice first )
827 [ rest-slice ] [ first-unsafe ] bi ; inline
829 : 2unclip-slice ( seq1 seq2 -- rest-slice1 rest-slice2 first1 first2 )
830 [ unclip-slice ] bi@ swapd ; inline
832 : map-reduce ( seq map-quot reduce-quot -- result )
833 [ [ unclip-slice ] dip [ call ] keep ] dip
834 compose reduce ; inline
836 : 2map-reduce ( seq1 seq2 map-quot reduce-quot -- result )
837 [ [ 2unclip-slice ] dip [ call ] keep ] dip
838 compose 2reduce ; inline
842 : (map-find) ( seq quot find-quot -- result elt )
843 [ [ f ] 2dip [ [ nip ] dip call dup ] curry ] dip call
844 [ [ drop f ] unless ] dip ; inline
848 : map-find ( seq quot -- result elt )
849 [ find ] (map-find) ; inline
851 : map-find-last ( seq quot -- result elt )
852 [ find-last ] (map-find) ; inline
854 : unclip-last-slice ( seq -- butlast-slice last )
855 [ but-last-slice ] [ last ] bi ; inline
857 : <flat-slice> ( seq -- slice )
858 dup slice? [ { } like ] when
859 [ drop 0 ] [ length ] [ ] tri <slice> ;
864 : (trim-head) ( seq quot -- seq n )
865 over [ [ not ] compose find drop ] dip
866 [ length or ] keep swap ; inline
868 : (trim-tail) ( seq quot -- seq n )
869 over [ [ not ] compose find-last drop ?1+ ] dip
874 : trim-head-slice ( seq quot -- slice )
875 (trim-head) tail-slice ; inline
877 : trim-head ( seq quot -- newseq )
878 (trim-head) tail ; inline
880 : trim-tail-slice ( seq quot -- slice )
881 (trim-tail) head-slice ; inline
883 : trim-tail ( seq quot -- newseq )
884 (trim-tail) head ; inline
886 : trim-slice ( seq quot -- slice )
887 [ trim-head-slice ] [ trim-tail-slice ] bi ; inline
889 : trim ( seq quot -- newseq )
890 [ trim-slice ] [ drop ] 2bi like ; inline
892 : sum ( seq -- n ) 0 [ + ] binary-reduce ;
894 : product ( seq -- n ) 1 [ * ] binary-reduce ;
896 : infimum ( seq -- n ) [ ] [ min ] map-reduce ;
898 : supremum ( seq -- n ) [ ] [ max ] map-reduce ;
900 : sigma ( seq quot -- n )
901 [ 0 ] 2dip [ dip + ] curry [ swap ] prepose each ; inline
903 : count ( seq quot -- n ) [ 1 0 ? ] compose sigma ; inline
905 ! We hand-optimize flip to such a degree because type hints
906 ! cannot express that an array is an array of arrays yet, and
907 ! this word happens to be performance-critical since the compiler
908 ! itself uses it. Optimizing it like this reduced compile time.
911 : generic-flip ( matrix -- newmatrix )
912 [ dup first length [ length min ] reduce ] keep
913 [ [ nth-unsafe ] with { } map-as ] curry { } map-as ; inline
917 : array-length ( array -- len )
918 { array } declare length>> ; inline
920 : array-flip ( matrix -- newmatrix )
922 [ dup first array-length [ array-length min ] reduce ] keep
923 [ [ array-nth ] with { } map-as ] curry { } map-as ;
927 : flip ( matrix -- newmatrix )
931 [ array-flip ] [ generic-flip ] if
932 ] [ generic-flip ] if
935 : reduce1 ( seq quot -- result ) [ unclip ] dip reduce ; inline
938 ( list identity quot: ( obj1 obj2 -- obj ) -- result )
941 [ list rest identity quot reduce-r list first quot call ] if ;
944 :: combos ( list1 list2 -- result ) list2 [ [ 2array ] curry list1 swap map ] map concat ;