https://github.com/Boereck/fn_block
Library for wrapping a Rust block or expression into a closure and call it.
https://github.com/Boereck/fn_block
closures macros rust
Last synced: about 1 year ago
JSON representation
Library for wrapping a Rust block or expression into a closure and call it.
- Host: GitHub
- URL: https://github.com/Boereck/fn_block
- Owner: Boereck
- License: apache-2.0
- Created: 2018-05-28T17:08:13.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2018-07-31T08:09:00.000Z (almost 8 years ago)
- Last Synced: 2024-10-08T08:44:34.438Z (over 1 year ago)
- Topics: closures, macros, rust
- Language: Rust
- Size: 26.4 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGES.md
- License: LICENSE-APACHE
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# `fn_block` Crate
Library defining macros for calling blocks or expressions in a closure.
## Quick Introduction
This library was mostly written to allow "safe navigation" with the `?.` operator combination
(seemingly) without jumping out of the current function. This allows a similar use of the operator
as in other languages (such as Swift, C# or Kotlin).
To use this library, you have to add it to the dependencies of your `Cargo.toml` file
```toml
[dependencies]
fn_block = "0.2.1"
```
Then add the following lines to your module:
```rust
#[macro_use]
extern crate fn_block;
use fn_block::*;
```
Instead of the wildcard, you can also just import the symbols you need.
Here is an example on how to use the crate:
```rust
let o = Some("Foobar");
let s = fn_expr!{ o?.get(0..3)?.to_lowercase().into_some() };
assert_eq!("foo", s.unwrap());
```
Please visit the [API Documentation](https://docs.rs/fn_block/latest/) for more details.
## Functionality Overview
In short, this crate provides the following APIs:
* The [`fn_expr`] macro allows wrapping an expression into a lambda that is directly called.
* The [`IntoSome`] trait, which is implemented for all `Sized` types, allows to call [`into_some`]
on a value to move it into an `Option::Some`.
* The [`IntoOk`] trait, which is implemented for all `Sized` types, allows to call [`into_ok`]
on a value to move it into an `Result::Ok`.
For more examples, please have a look at the test module.
## Unstable Features
To use unstable features, the dependency declaration in your `Cargo.toml` has to be updated:
```toml
[dependencies]
fn_block = { version = "0.2.1", features = ["unproven"] }
```
Note that this crate's unstable features *do* work on stable Rust.
The following unstable APIs are available:
* The [`fn_try`] macro allows wrapping an expression into a lambda, being called directly and recover from errors directly afterwards.
## License
The fn_block crate is licensed under the following licenses:
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) / http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) / http://opensource.org/licenses/MIT)
Choose under which you want to use the library.
[`fn_expr`]: https://docs.rs/fn_block/latest/fn_block/macro.fn_expr.html
[`fn_block`]: https://docs.rs/fn_block/latest/fn_block/macro.fn_block.html
[`fn_try`]: https://docs.rs/fn_block/latest/fn_block/macro.fn_try.html
[`IntoSome`]: https://docs.rs/fn_block/latest/fn_block/trait.IntoSome.html
[`into_some`]: https://docs.rs/fn_block/latest/fn_block/trait.IntoSome.html#tymethod.into_some
[`IntoOk`]: https://docs.rs/fn_block/latest/fn_block/trait.IntoOk.html
[`into_ok`]: https://docs.rs/fn_block/latest/fn_block/trait.IntoOk.html#tymethod.into_ok