├── .gitignore ├── Cargo.toml ├── LICENSE-APACHE.txt ├── LICENSE-MIT.txt ├── README.md ├── examples ├── from_error.rs ├── map_err.rs └── simple.rs ├── rust-toolchain └── src └── lib.rs /.gitignore: -------------------------------------------------------------------------------- 1 | /target 2 | **/*.rs.bk 3 | Cargo.lock 4 | -------------------------------------------------------------------------------- /Cargo.toml: -------------------------------------------------------------------------------- 1 | [package] 2 | name = "exit" 3 | version = "0.2.0" 4 | authors = ["Josh Mcguigan"] 5 | edition = "2018" 6 | description = "Custom exit status codes with ? in main" 7 | repository = "https://github.com/JoshMcguigan/exit" 8 | readme = "README.md" 9 | license = "MIT OR Apache-2.0" 10 | 11 | [dependencies] 12 | -------------------------------------------------------------------------------- /LICENSE-APACHE.txt: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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IN NO EVENT SHALL THE 18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 | SOFTWARE. 22 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # exit [![crates.io badge](https://img.shields.io/crates/v/exit.svg)](https://crates.io/crates/exit) 2 | 3 | This crate exposes a type, `Exit`, which allows using `?` in `main` while also specifying custom exit status codes. 4 | 5 | The goal of this crate was to provide a proof of concept and sample implementation for the ideas discussed in [this blog post](https://www.joshmcguigan.com/blog/custom-exit-status-codes-rust/). 6 | 7 | ## Example 8 | 9 | ```rust 10 | #![feature(try_trait)] 11 | use exit::{Exit, ExitDisplay}; 12 | 13 | use std::env; 14 | use std::option; 15 | 16 | #[derive(Debug)] 17 | enum MyErr { 18 | MissingArg, 19 | ParseErrorUserNum, 20 | ParseErrorGroupNum, 21 | } 22 | 23 | impl From for i32 { 24 | fn from(err: MyErr) -> Self { 25 | match err { 26 | MyErr::MissingArg => 2, 27 | MyErr::ParseErrorUserNum => 3, 28 | MyErr::ParseErrorGroupNum => 4, 29 | } 30 | } 31 | } 32 | 33 | // You can optionally implement ExitDisplay for your error type in order to print an error message 34 | // on exit 35 | impl ExitDisplay for MyErr { 36 | fn display(&self) -> String { 37 | format!("{:?}", self) 38 | } 39 | } 40 | 41 | impl From for MyErr { 42 | fn from(_: option::NoneError) -> Self { 43 | MyErr::MissingArg 44 | } 45 | } 46 | 47 | fn main() -> Exit { 48 | let user_num_string : String = env::args().skip(1).next()?; 49 | let group_num_string : String = env::args().skip(2).next()?; 50 | 51 | let user_num : u32 = user_num_string.parse() 52 | .map_err(|_| MyErr::ParseErrorUserNum)?; 53 | let group_num : u32 = group_num_string.parse() 54 | .map_err(|_| MyErr::ParseErrorGroupNum)?; 55 | 56 | println!("Hello, user #{} from group #{}!", user_num, group_num); 57 | 58 | Exit::Ok 59 | } 60 | ``` 61 | 62 | ## License 63 | 64 | Licensed under either of 65 | 66 | * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) 67 | * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) 68 | 69 | at your option. 70 | 71 | ### Contribution 72 | 73 | Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. 74 | -------------------------------------------------------------------------------- /examples/from_error.rs: -------------------------------------------------------------------------------- 1 | #![feature(try_trait)] 2 | use exit::Exit; 3 | 4 | use std::env; 5 | use core::option; 6 | use core::num; 7 | 8 | enum MyErr { 9 | MissingArg, 10 | ParseIntError, 11 | } 12 | 13 | impl From for i32 { 14 | fn from(err: MyErr) -> Self { 15 | match err { 16 | MyErr::MissingArg => 2, 17 | MyErr::ParseIntError => 3, 18 | } 19 | } 20 | } 21 | 22 | impl From for MyErr { 23 | fn from(_: option::NoneError) -> Self { 24 | MyErr::MissingArg 25 | } 26 | } 27 | 28 | impl From for MyErr { 29 | fn from(_: num::ParseIntError) -> Self { 30 | MyErr::ParseIntError 31 | } 32 | } 33 | 34 | fn main() -> Exit { 35 | let num_string= env::args().skip(1).next()?; 36 | let num : u32 = num_string.parse()?; 37 | 38 | println!("Hello, user #{}!", num); 39 | 40 | Exit::Ok 41 | } 42 | -------------------------------------------------------------------------------- /examples/map_err.rs: -------------------------------------------------------------------------------- 1 | #![feature(try_trait)] 2 | use exit::{Exit, ExitDisplay}; 3 | 4 | use std::env; 5 | use std::option; 6 | 7 | #[derive(Debug)] 8 | enum MyErr { 9 | MissingArg, 10 | ParseErrorUserNum, 11 | ParseErrorGroupNum, 12 | } 13 | 14 | impl From for i32 { 15 | fn from(err: MyErr) -> Self { 16 | match err { 17 | MyErr::MissingArg => 2, 18 | MyErr::ParseErrorUserNum => 3, 19 | MyErr::ParseErrorGroupNum => 4, 20 | } 21 | } 22 | } 23 | 24 | // You can optionally implement ExitDisplay for your error type in order to print an error message 25 | // on exit 26 | impl ExitDisplay for MyErr { 27 | fn display(&self) -> String { 28 | format!("{:?}", self) 29 | } 30 | } 31 | 32 | impl From for MyErr { 33 | fn from(_: option::NoneError) -> Self { 34 | MyErr::MissingArg 35 | } 36 | } 37 | 38 | fn main() -> Exit { 39 | let user_num_string : String = env::args().skip(1).next()?; 40 | let group_num_string : String = env::args().skip(2).next()?; 41 | 42 | let user_num : u32 = user_num_string.parse() 43 | .map_err(|_| MyErr::ParseErrorUserNum)?; 44 | let group_num : u32 = group_num_string.parse() 45 | .map_err(|_| MyErr::ParseErrorGroupNum)?; 46 | 47 | println!("Hello, user #{} from group #{}!", user_num, group_num); 48 | 49 | Exit::Ok 50 | } 51 | -------------------------------------------------------------------------------- /examples/simple.rs: -------------------------------------------------------------------------------- 1 | use exit::Exit; 2 | 3 | enum MyErr { 4 | OneLessThanZero, 5 | OneEqualsTwo, 6 | } 7 | 8 | impl From for i32 { 9 | fn from(err: MyErr) -> Self { 10 | match err { 11 | MyErr::OneLessThanZero => 2, 12 | MyErr::OneEqualsTwo => 3, 13 | } 14 | } 15 | } 16 | 17 | fn main() -> Exit { 18 | if 1 < 0 { 19 | return Exit::Err(MyErr::OneLessThanZero) 20 | } else if 1 == 2 { 21 | return Exit::Err(MyErr::OneEqualsTwo) 22 | } 23 | 24 | Exit::Ok 25 | } 26 | -------------------------------------------------------------------------------- /rust-toolchain: -------------------------------------------------------------------------------- 1 | nightly 2 | -------------------------------------------------------------------------------- /src/lib.rs: -------------------------------------------------------------------------------- 1 | #![feature(termination_trait_lib)] 2 | #![feature(try_trait)] 3 | #![feature(specialization)] 4 | 5 | use std::process::Termination; 6 | use std::ops::Try; 7 | 8 | pub enum Exit { 9 | Ok, 10 | Err(T) 11 | } 12 | 13 | pub trait ExitDisplay { 14 | fn display(&self) -> String; 15 | } 16 | 17 | impl> Termination for Exit { 18 | default fn report(self) -> i32 { 19 | match self { 20 | Exit::Ok => 0, 21 | Exit::Err(err) => { 22 | err.into() 23 | }, 24 | } 25 | } 26 | } 27 | 28 | impl + ExitDisplay> Termination for Exit { 29 | fn report(self) -> i32 { 30 | match self { 31 | Exit::Ok => 0, 32 | Exit::Err(err) => { 33 | eprintln!("{}", err.display()); 34 | err.into() 35 | }, 36 | } 37 | } 38 | } 39 | 40 | impl Try for Exit { 41 | type Ok = (); 42 | type Error = T; 43 | 44 | fn into_result(self) -> Result<::Ok, Self::Error> { 45 | match self { 46 | Exit::Ok => Ok(()), 47 | Exit::Err(err) => Err(err) 48 | } 49 | } 50 | 51 | fn from_error(err: Self::Error) -> Self { 52 | Exit::Err(err) 53 | } 54 | 55 | fn from_ok(_: ::Ok) -> Self { 56 | Exit::Ok 57 | } 58 | } 59 | --------------------------------------------------------------------------------