[Caml-list] ocamlbuild add unexpected directories to including-dirs while building multi-targets

[Caml-list] ocamlbuild add unexpected directories to including-dirs while building multi-targets

[ZAN DoYe]

suppose the dir tree is:

.
├── a
│   ├── a.ml (let v= I.a)
│   ├── i
│   │   └── i.ml (let a= 1)
│   └── _tags ("i": include)
├── b
│   ├── b.ml (let v= I.b)
│   ├── i
│   │   └── i.ml (let b= 1)
│   └── _tags ("i": include)
├── myocamlbuild.ml (an empty file)
└── o.itarget (a/a.byte \n b/b.byte)

after running ocamlbuild o.otarget, the error info:

Finished, 1 target (0 cached) in 00:00:00.
+ /home/kandu/.opam/4.02.3/bin/ocamlc.opt -c -I a -I b/i -I a/i -o a/a.cmo a/a.ml
File "a/a.ml", line 1, characters 7-10:
Error: Unbound value I.a

Is there any way to isolate including-dirs while compiling multi-targets?

Re: [Caml-list] ocamlbuild add unexpected directories to including-dirs while building multi-targets

[Christian Lindig]

> On 18 Oct 2015, at 10:18, ZAN DoYe <zandoye@gmail.com> wrote:
> 
> Is there any way to isolate including-dirs while compiling multi-targets?

> .
> ├── a
> │   ├── a.ml (let v= I.a)
> │   ├── i
> │   │   └── i.ml (let a= 1)
> │   └── _tags ("i": include)
> ├── b
> │   ├── b.ml (let v= I.b)
> │   ├── i
> │   │   └── i.ml (let b= 1)
> │   └── _tags ("i": include)
> ├── myocamlbuild.ml (an empty file)
> └── o.itarget (a/a.byte \n b/b.byte)

I believe you can’t have two modules I (a/i/i.ml and b/i/i.ml) in the project. While the two are in different directories, they are both top-level modules in the language.

— Christian

Re: [Caml-list] ocamlbuild add unexpected directories to including-dirs while building multi-targets

[ZAN DoYe]

On 2015-10-18 17:44, Christian Lindig wrote:
> I believe you can’t have two modules I (a/i/i.ml and b/i/i.ml) in the project. While the two are in different directories, they are both top-level modules in the language.
Thanks. I think it's common that two targets contain modules with the same name. e.g. targetA.Init and targetB.Init. each target has a Init module to initialize themself. It'll be convenient if ocamlbuild isolates inc-dir for each target.

For now, Do I have to structure my targets as separate ocamlbuild projects?

Re: [Caml-list] ocamlbuild add unexpected directories to including-dirs while building multi-targets

[Daniel Bünzli]

Le dimanche, 18 octobre 2015 à 12:03, ZAN DoYe a écrit :
> Thanks. I think it's common that two targets contain modules with the same name. e.g. targetA.Init and targetB.Init. each target has a Init module to initialize themself. It'll be convenient if ocamlbuild isolates inc-dir for each target.

Note that if you are writing libraries you should prefix these names anyway as they would exist in the global toplevel namespace and hence potentially clash with other libraries.  

That said I'm also often hit by the limitations you mention when I have libraries that provide multiple implementations of the same interface. The work around is to avoid `include`ing the directories in your _tags file and invoke ocamlbuild with the `-I` option, see for example [1].  

Best,

Daniel

[1] https://github.com/dbuenzli/mtime/blob/a9dafd38002bfd8bdc5d3c3963e2d2d446c2ad6a/build#L19-L20

Re: [Caml-list] ocamlbuild add unexpected directories to including-dirs while building multi-targets

[Christian Lindig]

> On 18 Oct 2015, at 12:46, ZAN DoYe <zandoye@gmail.com> wrote:
> 
> On 2015-10-18 17:44, Christian Lindig wrote:
>> I believe you can’t have two modules I (a/i/i.ml and b/i/i.ml) in the project. While the two are in different directories, they are both top-level modules in the language.
> Thanks. I think it's common that two targets contain modules with the same name. e.g. targetA.Init and targetB.Init. each target has a Init module to initialize themself.
> It's be more convenient if ocamlbuild isolates inc-dir for each target.
> 
> For now, Do I have to structure my targets as separate ocamlbuild projects?
> 

If you want sub-modules A.I and B.I, it would be easiest to implement the respective I inside A and B but not as separate files:

a.ml:
module I = struct
  let a = 1
end 
let v = I.a

b.ml:
module I = struct
  let b = 1
end 
let v = I.b

— Christian