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Lists

type t<elt> = list<elt>

The type `t` is an alias for the predefined type `list`.

empty: <elt>t<elt>

The value List.empty is the empty list. It is a synonym for list([]). In some contexts, it is useful to annotate it with its type, for example: (empty as list<int>).

length: <elt>(list: t<elt>) => nat

The call List.length(l) is the number of elements in the list l. Note: List.length is another name for List.size.

size: <elt>(list: t<elt>) => nat

The call List.size(l) is the number of elements in the list l.

head: <elt>(list: t<elt>) => option<elt>

The call List.head(l), where l is a list, is ["None" as "None"] if l is empty; otherwise, ["Some" as "Some", hd], where hd is the head of the list.

tail: <elt>(list: t<elt>) => option<t<elt>>

The call List.tail(l), where l is a list, is ["None" as "None"] if l is empty; otherwise, ["Some" as "Some", tl], where tl is the tail of the list.

head_and_tail: <elt>(list: t<elt>) => option<elt,t< elt>>

The call List.head_and_tail(l), where l is a list, is ["None" as "None"] if l is empty; otherwise, ["Some" as "Some", [hd,tl]], where hd and tl are the head and tail of the list, respectively.

map: <src, dst>(f: (_: src) => dst, list: t<src>) => t<dst>

The call List.map(f, list([a1; ...; an])) applies the function f to a1, ..., an (from left to right), and builds the list list([f(a1); ...; f(an)]) with the results returned by f.

iter: <elt>(f: (_: elt) => unit, list: t<elt>) => unit

The call List.iter(f, list([a1; ...; an])) applies the function f in turn to list([a1; ...; an]). It is equivalent to {f(a1); f(a2); ...; f(an)}.

fold_left: <elt, acc>(f: (_: [acc, elt]) => acc, init: acc, list: t<elt>) => acc

The call List.fold_left(f, init, list([a1; ...; an])) is f (... (f (f(init, a1)), a2), ...), an).

fold_right: <elt, acc>(f: (_: [elt, acc]) => acc, list: t<elt>, init: acc) => acc

The call List.fold_right(f, list([a1; ...; an]), init) is f (a1, f (a2, (..., f (an, init))...)).

fold: <elt, acc>(f: (_: [acc, elt]) => acc, list: t<elt>, init: acc) => acc

The call List.fold(f, list([a1; ...; an]), init) is f (... (f (f (init, a1), a2) ...), an). Note: List.fold_left(f, init, list) is the same as List.fold(f, list, init).

cons: <elt>(elt: elt, list: t<elt>) => t<elt>

The call List.cons(e, l) is list([e, ...l]).

find_opt: <elt>(f: (_: elt) => bool, list: t<elt>) => option<elt>

The call List.find_opt(pred, list) is ["None" as "None"] if no element of the list list satisfies the predicate pred; otherwise, it is ["Some" as "Some", e], where e is the leftmost element in list that satisfies pred. The order of the calls of pred is not specified.

filter_map: <src, dst>(filter: (_: src) => option<dst>, list: list<src>) => list<dst>

The call List.filter_map(f, l) is the maximal sub-list of l such that the call of function f on its elements is not ["None" as "None"]. Note: f is called on all elements of l. The order of the calls of f is not specified.

update: <elt>(filter: (_: elt) => option<elt>, list: t<elt>) => t<elt>

The call List.update(f, l) is the list l where the elements e such that f(e) is ["Some" as "Some", v] have been replaced by v.

update_with: <elt>(pred: (_: elt) => bool, default: elt, list: t<elt>) => t<elt>

The call List.update_with(p,d,l) is the list l where the elements e such that satisfy the predicate p are replaced by d.