Module Generic_core_consumer

module Generic_core_consumer: sig .. end

Extensible type-indexed consumers.

Consumers are a special case of type-indexed functions which consume a value of the type index and produce something independent of that type. They have a signature of the form: forall 'a . 'a ty -> 'a -> b for some type b independent of 'a.

Specialising Generic_core_extensible, allows us to get rid of the Generic_util_app.t datatype.

See Generic_core_extensible for more details.

type 'b ty_fun = {

f : 'a. 'a Ty.ty -> 'a -> 'b;

}

Type-indexed consumer function

type 'b closure = {

	`f : 'a. 'a Ty.ty -> 'a -> 'b;`	`(*`	`f`: applies the extensible function. Raises `Generic_core_extensible.Type_pattern_match_failure` when the type index doesn't match any of the patterns in the collection.	`*)`
	`ext : 'a. 'a Ty.ty -> 'b ty_fun -> unit;`	`(*`	`ext`: extends the function with a new case. We must provide a type pattern, (example: `List Any`). The `ty_fun` provided is only expected to handle types matching with the pattern. Effectful. Raises `Generic_core_extensible.Pattern_overwrite` when called with a type pattern that was already registered.	`*)`

}

A closure allows us to call a type-indexed consumer and to extend it to new type cases.

val create : string -> 'a closure

create name, creates a new closure initially empty: calling f will raise Type_pattern_match_failure. The name is used in the exception messages. Effectful.