If I want to extend List with additional functions, I can just do: include module type of List val flat_map : ('a -> 'b list) -> 'a list -> 'b list include List let flat_map f l = flatten (map f) l and that’s fine. But if I want to extend Format, this simple trick doesn’t work so well, because t…

Easy peasy! There is an OCaml idiom for that: include module type of struct include Format end To understand why that works, you need a bit of knowledge on the module type system. The basic idea is the following: the struct include X end dance forces the typechecker to “strengthen” the module sign…

Extend existing module

Learning

c-cube January 6, 2018, 2:26pm 7

really neat, thank you!

Topic		Replies	Views
ICFP and improvement of module language Learning	19	867	October 29, 2024
De-duplicating module signatures that depend on abstract data types Learning module	11	3319	May 24, 2019
Managing functor dependencies Learning	24	1407	September 24, 2021
Concise Module Syntax Community language-design , ideas	23	4439	January 5, 2018
Modules that extend modules from third-party packages Ecosystem package-design	2	2576	May 9, 2019

Extend existing module

Related topics