I haven't used D, but in Haskell we have the same module name == file name thing. The only time I don't like it is when we have nested modules, the parent and children modules are not in the same directory:

    import A      -- compiler reads A.hs
    import A.B    -- compiler reads A/B.hs

Thus, two semantically related modules are now in different directories.

Python, IMO, handles this correctly by having __init__.py support inside directories. It's theoretically less elegant because of the special name, but in practice leads to better file organization.

Same for Rust, but even better, because one can define nested modules in the same file. So you can either define a new module in the same file, put it in a different file named by the module, or put it in the file `mod.rs` inside the directory named by the module.