Module Core_extended.Fold_map

A map that folds in new values.

An example would be a multi-map in which a key is initialized with the empty list as its value, and adding a new key/value pair appends the value to the key's list.

module type Foldable : sig ... end

Input signature of the functor Make

module type S : sig ... end

Output signature of the functor Make

module Make : functor (Fold : Foldable) -> S with type in_value = Fold.data and type out_value = Fold.t

Builds a fold_map

Sexpable interface

Same as above but builds the sexp_of and of_sexp functions. Requires the passed in types to be sexpable.

module type S_sexpable : sig ... end

module type Foldable_sexpable : sig ... end

module Make_sexpable : functor (Fold : Foldable_sexpable) -> S_sexpable with type in_value = Fold.data and type out_value = Fold.t

Polymorphic folds

Polymorphic fold take a

module type Foldable2 : sig ... end

module type S2 : sig ... end

module Make2 : functor (Fold : Foldable2) -> S2 with type 'a out_value = 'a Fold.t

Sexpable interface

module type Foldable2_sexpable : sig ... end

module type S2_sexpable : sig ... end

module Make2_sexpable : functor (Fold : Foldable2_sexpable) -> S2_sexpable with type 'a out_value = 'a Fold.t

Predefined modules

module Cons : S2_sexpable with type 'a out_value = 'a list

module Add : S_sexpable with type in_value = int and type out_value = int

A fold for adding. e.g. symbol positions

module Multiply : S_sexpable with type in_value = int and type out_value = int