Extensions to Core.List.
val of_option : 'a option ‑> 'a listof_option o returns a list that is empty if o is None, otherwise it is a singleton
list. Useful to get filter_map-like behavior in the context of something like a
concat_map.
val set_inter : 'a list ‑> 'a list ‑> 'a listset_inter l1 l2 returns a list without duplicates of all elements of l1 that are in l2
val set_diff : 'a list ‑> 'a list ‑> 'a listset_diff l1 l2 returns a list of all elements of l1 that are not in l2
val classify : ?equal:('b ‑> 'b ‑> bool) ‑> f:('a ‑> 'b) ‑> 'a list ‑> ('b * 'a list) listclassify l ~equal ~f elements x and y of list l are assigned to the
same class iff equal (f x) (f y) returns true. The default for equal is ( = )
val enumerate_from : int ‑> 'a list ‑> ('a * int) listenumerate_from n xs returns a list of pairs constructed by pairing an
incrementing counter, starting at n, with the elements of xs.
e.g. enumerate_from 1 a,b,c = a,1; b,2; c,3
val map_accum : 'a list ‑> f:('b ‑> 'a ‑> 'b * 'c) ‑> init:'b ‑> 'b * 'c listA combination of map and fold. Applies a function to each element of the input
list, building up an accumulator, returning both the final state of the accumulator
and a new list.
Numbers the elements in a list by occurence:
[a;b;c;a;d] -> [(a,0);(b,0);(c,0);(a,1);(d,0)]
val multimerge : 'a list list ‑> 'a listMerges several list trying to keep the order in which the elements appear. The elements of the individual are not deduped.
multimerge [[a;b;d;a] [b;c;d]] -> [a;b;c;d;a]
val square : ?null:'v ‑> ('k * 'v) list list ‑> 'k list * 'v list listTakes a list of `key*`value lists and returns a
header * table_body body that is obtained by splitting the lists and
re-ordering the terms (so that they all have the same header).
If null_value is not specified and the rows have different keys
the function will raise an exception.
square ~null
[[(1,a_1);(2,b_1);(4,c_1)];
[(3,a_2)];
[(0,a_3);(1,b_3);(2,c_3);(3,d_3);(4,e_3)]]
=
([0 ;1 ;2 ;3 ;4],
[[null;a_1 ;b_1 ;null;c_1 ]
[null;null;null;a_2 ;null]
[a_3 ;b_3 ;c_3 ;d_3 ;e_3 ]])