https://github.com/sof3/dirmod
Automatic `mod` declaration with visibility/re-export customization, conditional compilation and more.
https://github.com/sof3/dirmod
Last synced: 5 months ago
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Automatic `mod` declaration with visibility/re-export customization, conditional compilation and more.
- Host: GitHub
- URL: https://github.com/sof3/dirmod
- Owner: SOF3
- License: apache-2.0
- Created: 2019-10-06T05:56:17.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2023-03-20T11:58:37.000Z (almost 3 years ago)
- Last Synced: 2025-05-01T00:55:14.579Z (9 months ago)
- Language: Rust
- Homepage: https://docs.rs/dirmod/
- Size: 4.05 MB
- Stars: 21
- Watchers: 2
- Forks: 2
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# dirmod
[](https://travis-ci.om/SOF3/dirmod)
[](https://crates.io/crates/dirmod)
[](https://crates.io/crates/dirmod)
[](https://sof3.github.io/dirmod/)
[](https://github.com/SOF3/dirmod)
Tired of writing and updating all the `mod` statements in mod.rs?
Generate them with `dirmod` instead.
`dirmod` scans your directory and generates the corresponding `mod` statements automatically
with a simple macro call:
```rust
dirmod::all!();
```
And that's all!
> *(Note: `dirmod` is designed for [Rust 2018 Edition][rust-2018],
so macros take simple and ambiguous names like `all`, `os`, etc.
It is recommended to call the macros in fully-qualified fashion
like `dirmod::all!()`, `dirmod::os!()`, etc. for clarity.
The old `#[macro_use] extern crate dirmod;` style is not recommended.)*
## Visibility
### Default visibility
All modules can be set to a common visibility,
e.g. `pub mod` or `pub(self) mod`, etc. at your favour:
```rust
dirmod::all!(default pub);
```
### Re-exporting
You can also make all modules private, and set the visibility for the *re-exported* items instead:
```rust
dirmod::all!(default pub use);
```
### Separate file defaults and directory defaults
It might be common to handle file modules and directory modules separately:
```rust
dirmod::all!(default file pub use; default dir pub);
```
This re-exports all items from file modules, and makes all directory modules public by name.
(This behaviour is similar to the package system in Go)
### The default behaviour
If the `default` argument is not given, `default file priv use; default dir priv` is the default
choice.
### Individual visibility
If there are individual modules among dozens that need special visibility configuration,
it is also possible to write:
```rust
dirmod::all!(default pub; priv foo, bar);
```
Then all modules have `pub` visibility,
except `foo` and `bar` which are private.
Similarly, if all modules are publicly re-exported and `foo` and `bar` are only exported as modules:
```rust
dirmod::all!(default pub use; pub foo, bar);
```
## Conditional compilation
> But I use `mod` to implement conditional compilation!
No problem, `dirmod` generates `cfg` attributes for some idiomatic styles:
- A directory where each module name is the feature name (e.g. `#[cfg(feature = "foo")] mod foo;`)
- A directory where each module name is the OS/OS family name (e.g. `#[cfg(target_family = "unix")] mod unix;`)
This can be achieved by calling `dirmod::os!()`, `dirmod::family!()` or `dirmod::feature!()`.
It is likely that different OS variants of the same module expose the same API,
so it might be practical to write:
```rust
dirmod::os!(pub use);
```
If none of the modules support the current OS, you could trigger a compile error:
```rust
dirmod::os!(pub use ||);
```
Or with a custom error message:
```rust
dirmod::os!(pub use || "custom error message");
```
Note that it does not make sense to use the `||` on `dirmod::feature!`,
because Cargo features are incremental and should not be restricted in amount.
[File an issue][gh-issues] if I missed any common styles!
## But I am still unhappy about xxxx corner case!
No problem, you don't have to use `dirmod` for every module.
`dirmod::all!()` has an `except` argument that excludes certain modules.
Since the macro simply generates `mod` statements,
it is perfectly fine to add more items before/after the macro call.
```rust
dirmod::all!(except corge, grault);
```
## Documentation
Instead of writing docs in mod.rs, write them in the module directly.
In addition to `dirmod` constraints, there are a few advantages:
- Avoid lots of docs mixed together in a single mod.rs. Easier to navigate!
- Writing docs inside the module itself is much more relevant than references to the parent module.
To write docs for the module, use this syntax at the top of the module (before any other items):
```rust
//! Yay, I'm now describing myself!
//! I finally have my own place!
```
## Supported Rust versions
Since detecting the source file requires the [`proc_macro_span`][proc-macro-span-issue] feature,
Rust Nightly is required to compile this crate.
## Examples
See the [`testcrate`][testcrate-blob] directory, which demonstrates the use of `dirmod::all!` and `dirmod::family!`.
## Syntax reference
A BNF syntax reference is available at [`syntax.bnf`][bnf-blob].
## Known unresolved issues
### `rustfmt` support
`rustfmt` and `cargo fmt` operate on the modules directly included by the entry points
by detecting direct `mod` statements in the included files.
Since `rustfmt` does not expand (or even compile) macros ([known issue][rustfmt-issue]),
modules included by `dirmod` would not be formatted.
The most straightforward alternative for now is to run `rustfmt src/**/*.rs`
with `shopt -s globstar` enabled on a Linux shell.
### Error reporting
The Rust compiler may fail to locate syntax error locations correctly
([known issue][compiler-issue]).
However, this issue has only been reproduced with the specific case
where the syntax error is related to leading `#[]` which could be an inner attribute.
[rust-2018]: https://doc.rust-lang.org/edition-guide/rust-2018/index.html
[gh-issues]: https://github.com/SOF3/dirmod
[proc-macro-span-issue]: https://github.com/rust-lang/rust/issues/54725
[testcrate-blob]: https://github.com/SOF3/dirmod/tree/master/testcrate
[bnf-blob]: https://github.com/SOF3/dirmod/blob/master/syntax.bnf
[rustfmt-issue]: https://github.com/rust-lang/rustfmt/issues/3253
[compiler-issue]: https://github.com/rust-lang/rust/issues/66071