Re: [Caml-list] Are implicit modules too implicit?

[Malcolm Matalka <mmatalka@gmail.com>]

Leo White <leo@lpw25.net> writes:

>> To me, this means going from a call-site, to the actual
>> implementation is very difficult especially since I cannot even do some
>> sort of grep to find all those things that implement an implicit module
>> type.
>
> The best way of finding a variable's definition is to use merlin to jump to definition.
> The same will be true for implicit call sites.

In this case I'm interested in if I have a block of code like the
[print] function described in the paper knowing what possible code could
even be executed there and how to define its definition.  For example,
how do I go from [show 5] to the module [Show_int]?

>
> Depending on how libraries are designed I would not expect it to be difficult to locate
> the instances by hand. They are managed with the same scoping mechanisms as
> ordinary values, and since they should rarely be used by name they can also be
> given nice descriptive searchable names.

In the paper, the Show implementation for an int is called Show_int and
for list Show_list, etc.  But this is just a pleasant convention in the
paper.  What if implicit modules required specifying what module type
they are implementing?  That would make finding instances of Show
easier.  How this would look is in the paper:

implicit module Foo : Show = struct ... end

Certainly this isn't needed for correctness, but it seems nicer than
hoping people name their instances something sensible.

Do you have any thoughts on how you think implicit modules would effect
understanding a large application?

>
> Regards,
>
> Leo