infer_clone/sledge/nonstdlib/option.mli

(*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *)

open! NS0
include module type of Containers.Option

type 'a t = 'a option [@@deriving compare, equal, hash, sexp]

val pp : ('a_pp -> 'a -> unit, unit) fmt -> 'a_pp -> 'a option pp
val map : 'a t -> f:('a -> 'b) -> 'b t
val map_or : 'a t -> default:'b -> f:('a -> 'b) -> 'b
val bind : 'a t -> f:('a -> 'b t) -> 'b t
val iter : 'a t -> f:('a -> unit) -> unit
val exists : 'a t -> f:('a -> bool) -> bool
val for_all : 'a t -> f:('a -> bool) -> bool
val fold : 'a t -> 's -> f:('a -> 's -> 's) -> 's
[sledge] Move Import.Option to separate module Reviewed By: ngorogiannis Differential Revision: D20482757 fbshipit-source-id: 492674549 5 years ago			`(*`
			`* Copyright (c) Facebook, Inc. and its affiliates.`
			`*`
			`* This source code is licensed under the MIT license found in the`
			`* LICENSE file in the root directory of this source tree.`
			`*)`

[sledge] Build: Promote `import` subdirectory to a toplevel `nonstdlib` library Reviewed By: jvillard Differential Revision: D21720977 fbshipit-source-id: 0b9001eea 5 years ago			`open! NS0`
[sledge] Switch from Base.Option to Containers.Option Reviewed By: ngorogiannis Differential Revision: D24306079 fbshipit-source-id: e42b45cfa 4 years ago			`include module type of Containers.Option`
[sledge] Move Import.Option to separate module Reviewed By: ngorogiannis Differential Revision: D20482757 fbshipit-source-id: 492674549 5 years ago
[sledge] Switch from Base.Option to Containers.Option Reviewed By: ngorogiannis Differential Revision: D24306079 fbshipit-source-id: e42b45cfa 4 years ago			`type 'a t = 'a option [@@deriving compare, equal, hash, sexp]`
[sledge] Add Option.or_else Summary: ``` val or_else : (unit -> 'a option) -> 'a option -> 'a option (** [or_else f] is [f ()] on [None] and otherwise identity *) ``` Reviewed By: jvillard Differential Revision: D20637481 fbshipit-source-id: 72a9d930f 5 years ago
[sledge] Switch from Base.Option to Containers.Option Reviewed By: ngorogiannis Differential Revision: D24306079 fbshipit-source-id: e42b45cfa 4 years ago			`val pp : ('a_pp -> 'a -> unit, unit) fmt -> 'a_pp -> 'a option pp`
			`val map : 'a t -> f:('a -> 'b) -> 'b t`
			`val map_or : 'a t -> default:'b -> f:('a -> 'b) -> 'b`
			`val bind : 'a t -> f:('a -> 'b t) -> 'b t`
			`val iter : 'a t -> f:('a -> unit) -> unit`
			`val exists : 'a t -> f:('a -> bool) -> bool`
			`val for_all : 'a t -> f:('a -> bool) -> bool`
[sledge] Change type of fold functions for improved composition Summary: Change the type of `fold` functions to enable them to compose better. The guiding reasoning behind using types such as: ``` val fold : 'a t -> 's -> f:('a -> 's -> 's) -> 's ``` is: 1. The function argument should be labeled. This is so that it can be reordered relative to the others, since it is often a multi-line `fun` expression. 2. The function argument should come last. This enables its arguments (which are often polymorphic) to benefit from type-based disambiguation information determined by the types of the other arguments at the call sites. 3. The function argument's type should produce an accumulator-transformer when partially-applied. That is, `f x : 's -> 's`. This composes well with other functions designed to produce transformers/endofunctions when partially applied, and in particular improves the common case of composing folds into "state-passing style" code. 4. The fold function itself should produce an accumulator-transformer when partially applied. So `'a t -> 's -> f:_ -> 's` rather than `'s -> 'a t -> f:_ -> 's` or `'a t -> init:'s -> f:_ -> 's` etc. Reviewed By: jvillard Differential Revision: D24306063 fbshipit-source-id: 13bd8bbee 4 years ago			`val fold : 'a t -> 's -> f:('a -> 's -> 's) -> 's`