[Ocaml-lib-devel] Suggestion for Option module

[Bardur A. <oca...@sc...>]

Hi there,

I have a suggestion for an additional function to put in
the Option module:

  let map_default f default = function
      | None -> default
      | Some v -> f v
    
As you can see it's sort of "Option.may for expressions".
I chose the name map_default because the function is
basically a combination of Option.map and Option.default.
Its behaviour is exactly identical to

     Option.default default (Option.map f x)

where x is the last parameter to map_default.

It can be convenient to have this function when building
predicates for e.g. Set.for_all when the set in question
contains option-type values. I also find that having one
function for the job instead of having to string
Option.map and Option.default together reduces clutter.

Cheers,

-- 
Bardur Arantsson
<ba...@im...>
<ba...@sc...>

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