10 releases
0.2.6 | Mar 20, 2019 |
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0.2.5 | Mar 20, 2019 |
0.1.2 | Mar 17, 2019 |
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Getters By Type
This crate provides GettersByType
derive macro for structs, which implements a getter method for each type they contain.
The generated methods start with the prefix get_fields_
and end with a transcription of the type they refer.
Example using GettersByType
:
#[derive(GettersByType)]
struct Foo {
first: i32,
second: i32,
third: i32,
}
let object = Foo { first: 6, second: 12, third: 24 };
// Let's sum all the i32 fields with a fold expression:
assert_eq!(object.get_fields_i32().iter().fold(0, |acc, x| **x + acc), 42);
As you notice, the getter methods return an array containing references to all the fields of the same type.
In that example, the return type of the method get_fields_i32
would be [&i32; 3]
.
This crate also provides a mut
version GettersMutByType
which also adds a mut version for those methods.
In this case, the generated methods start with the prefix get_mut_fields_
instead.
Example using GettersMutByType
:
#[derive(GettersMutByType)]
struct Foo {
first: Updater,
second: Updater,
...
onehundredth: Updater,
}
impl Updater {
fn update(&mut self) {...}
}
let mut object = Foo::new();
// Let's update all the Updater fields
for updater in object.get_mut_fields_updater().iter_mut() {
updater.update();
}
In this example, the return type of the method get_mut_fields_updater
would be [&mut Updater; 3]
.
There is no dynamic memory allocation happening within the getter methods, as they just return a fixed array with references.
There isn't also unsafe code being generated.
For more information, check the documentation page.
Usage
With Cargo, you can add this line to your Cargo.toml:
[dependencies]
getters-by-type = "*"
Development
This currently works with primitive types, and many other referencial and genecic types, such as &str
or Vec
, but there are cases that are not completely covered, like the trait objects. Want to contribute? Pull requests are always welcome. Because this is my first work with procedural macros, I guess things can improve a fair lot under the hood, so there should be a few low hanging fruits already. Let's go for them!
License
MIT
Dependencies
~2MB
~46K SLoC