dune init appears to ignore its name argument

[emengd]

Dune version: 2.1.3

When I do dune init exe myexe I get the following dune file:

(executable
 (name main))

plus a file main.ml.

I expect name myexe and a myexe.ml file. Did I misunderstand what dune init is supposed to do?

[shonfeder]

Thanks for the report, @emengd!

So, under the current behavior, the name argument for executable components only applies to the public_name field. E.g., (note the addition of the --public flag):

[sf@comp dune_test]$ dune init exe myexe --public
Success: initialized executable component named myexe
[sf@comp dune_test]$ cat dune 
(executable
 (public_name myexe)
 (name main))

This entails that all initialized .ml files for executable components (whether public or private) will be called main.ml. The (admittedly confusing) result is that the name is simply ignored when the executable component is not public! I can't recall whether this was a design error or an implementation error, but it is confusing behavior regardless.

• re: private components, it seems like the right thing to do is to name the .ml files the way you were expecting.
• re: public components, I am not sure whether or not we want to change the behavior, since it might be viewed as a positive that we enforce the (imo, reasonable) convention that the main module of public executables is named main.

[emengd]

Thanks for the answer! One thing I can say is that I would definitely expect to get (name myexe) based on the current documentation (by which I mean dune init --help). The meta-variable is called NAME, and there is a --public option that sets the public name and “defaults to the name”, so you expect this argument to become the name field.

I would also find it confusing if the positional argument had a different meaning depending on whether --public is present.

Here are two states that I find not confusing:

1. The argument is called PUBLIC_NAME. Components are public when it is present, and it determines the value of public_name. Otherwise they are private. There could be an option to set the name that defaults to main (with perhaps no argument meaning “same as public”).

2. The argument is NAME. It sets name in all cases. The public name can only come from --public (the behaviour I was expecting).

[shonfeder]

I agree with your reasoning. Indeed, the current inline help (which I wrote) is incorrect, as it reads:

       Define an executable component named 'myexe' in a dune file in the
       current directory:

                 dune init exe myexe

I prefer option 2, as it keeps the CLI more uniform across components. I'll plan to fix things in that way, unless I hear opinions otherwise.