if_chain-1.0.2/.cargo_vcs_info.json0000644000000001120000000000100125660ustar { "git": { "sha1": "24e822024b3832223ca679d0548187765bcc269c" } } if_chain-1.0.2/.github/workflows/ci.yml000064400000000000000000000015640072674642500161350ustar 00000000000000name: CI on: push: branches: - main pull_request: schedule: - cron: '0 1 27 * *' jobs: main: name: Main runs-on: ubuntu-latest strategy: fail-fast: false matrix: rust: - nightly - stable - 1.12.0 include: - rust: nightly components: clippy steps: - name: Check out repository uses: actions/checkout@v2 - name: Install Rust uses: actions-rs/toolchain@v1 with: toolchain: ${{ matrix.rust }} profile: minimal override: true components: ${{ matrix.components }} - name: Run tests uses: actions-rs/cargo@v1 with: command: test - if: ${{ matrix.rust == 'nightly' }} name: Check Clippy uses: actions-rs/cargo@v1 with: command: clippy args: -- -D warnings if_chain-1.0.2/.gitignore000064400000000000000000000000220072674642500133760ustar 00000000000000target Cargo.lock if_chain-1.0.2/CHANGELOG.md000064400000000000000000000017730072674642500132350ustar 00000000000000# Changelog ## [Unreleased] ## [1.0.2] - 2021-08-21 - Fix "trailing semicolon" warning for `let` statements with multiple patterns. ## [1.0.1] - 2020-09-29 - Update GitHub links from lfairy → lambda-fairy. ## [1.0.0] - 2019-05-22 - **Breaking change:** Update minimum Rust version to 1.12.0. - Expand `if` and `if let` to their equivalent expressions instead of `match`. - Work around an edge case regarding Rust's treatment of `block` matchers. ## [0.1.3] - 2018-07-20 - Add `local_inner_macros` attribute for compatibility with new-style macro imports. ## [0.1.2] - 2017-02-17 - Support `no_std`. [Unreleased]: https://github.com/lfairy/if_chain/compare/v1.0.2...HEAD [1.0.2]: https://github.com/lfairy/if_chain/compare/v1.0.1...v1.0.2 [1.0.1]: https://github.com/lfairy/if_chain/compare/v1.0.0...v1.0.1 [1.0.0]: https://github.com/lfairy/if_chain/compare/v0.1.3...v1.0.0 [0.1.3]: https://github.com/lfairy/if_chain/compare/v0.1.2...v0.1.3 [0.1.2]: https://github.com/lfairy/if_chain/compare/v0.1.1...v0.1.2 if_chain-1.0.2/Cargo.toml0000644000000014560000000000100106000ustar # THIS FILE IS AUTOMATICALLY GENERATED BY CARGO # # When uploading crates to the registry Cargo will automatically # "normalize" Cargo.toml files for maximal compatibility # with all versions of Cargo and also rewrite `path` dependencies # to registry (e.g., crates.io) dependencies. # # If you are reading this file be aware that the original Cargo.toml # will likely look very different (and much more reasonable). # See Cargo.toml.orig for the original contents. [package] name = "if_chain" version = "1.0.2" authors = ["Chris Wong "] description = "Macro for writing nested `if let` expressions." documentation = "https://docs.rs/if_chain" readme = "README.md" categories = ["rust-patterns", "no-std"] license = "MIT/Apache-2.0" repository = "https://github.com/lambda-fairy/if_chain" if_chain-1.0.2/Cargo.toml.orig000064400000000000000000000005350072674642500143060ustar 00000000000000[package] name = "if_chain" version = "1.0.2" authors = ["Chris Wong "] license = "MIT/Apache-2.0" documentation = "https://docs.rs/if_chain" repository = "https://github.com/lambda-fairy/if_chain" description = "Macro for writing nested `if let` expressions." categories = ["rust-patterns", "no-std"] readme = "README.md" if_chain-1.0.2/LICENSE-APACHE000064400000000000000000000251370072674642500133500ustar 00000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. 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See the License for the specific language governing permissions and limitations under the License. if_chain-1.0.2/LICENSE-MIT000064400000000000000000000020360072674642500130510ustar 00000000000000Copyright (c) 2018 Chris Wong Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. if_chain-1.0.2/README.md000064400000000000000000000012450072674642500126750ustar 00000000000000# if_chain [![Build Status](https://travis-ci.com/lambda-fairy/if_chain.svg?branch=master)](https://travis-ci.com/lambda-fairy/if_chain) [![Cargo](https://img.shields.io/crates/v/if_chain.svg)](https://crates.io/crates/if_chain) This crate provides a single macro called `if_chain!`. `if_chain!` lets you write long chains of nested `if` and `if let` statements without the associated rightward drift. It also supports multiple patterns (e.g. `if let Foo(a) | Bar(a) = b`) in places where Rust would normally not allow them. For more information on this crate, see the [documentation](https://docs.rs/if_chain) and associated [blog post](https://lambda.xyz/blog/if-chain). if_chain-1.0.2/src/lib.rs000064400000000000000000000172330072674642500133250ustar 00000000000000//! This crate provides a single macro called `if_chain!`. //! //! `if_chain!` lets you write long chains of nested `if` and `if let` //! statements without the associated rightward drift. It also supports multiple //! patterns (e.g. `if let Foo(a) | Bar(a) = b`) in places where Rust would //! normally not allow them. //! //! See the associated [blog post] for the background behind this crate. //! //! [blog post]: https://lambda.xyz/blog/if-chain //! //! # Note about recursion limits //! //! If you run into "recursion limit reached" errors while using this macro, try //! adding //! //! ```rust,ignore //! #![recursion_limit = "1000"] //! ``` //! //! to the top of your crate. //! //! # Examples //! //! ## Quick start //! //! ```rust,ignore //! if_chain! { //! if let Some(y) = x; //! if y.len() == 2; //! if let Some(z) = y; //! then { //! do_stuff_with(z); //! } //! } //! ``` //! //! becomes //! //! ```rust,ignore //! if let Some(y) = x { //! if y.len() == 2 { //! if let Some(z) = y { //! do_stuff_with(z); //! } //! } //! } //! ``` //! //! ## Fallback values with `else` //! //! ```rust,ignore //! if_chain! { //! if let Some(y) = x; //! if let Some(z) = y; //! then { //! do_stuff_with(z) //! } else { //! do_something_else() //! } //! } //! ``` //! //! becomes //! //! ```rust,ignore //! if let Some(y) = x { //! if let Some(z) = y { //! do_stuff_with(z) //! } else { //! do_something_else() //! } //! } else { //! do_something_else() //! } //! ``` //! //! ## Intermediate variables with `let` //! //! ```rust,ignore //! if_chain! { //! if let Some(y) = x; //! let z = y.some().complicated().expression(); //! if z == 42; //! then { //! do_stuff_with(y); //! } //! } //! ``` //! //! becomes //! //! ```rust,ignore //! if let Some(y) = x { //! let z = y.some().complicated().expression(); //! if z == 42 { //! do_stuff_with(y); //! } //! } //! ``` //! //! ## Type ascription //! //! ```rust,ignore //! let mut x = some_generic_computation(); //! if_chain! { //! if x > 7; //! let y: u32 = another_generic_computation(); //! then { x += y } //! else { x += 1 } //! } //! ``` //! //! becomes //! //! ```rust,ignore //! let mut x = some_generic_computation(); //! if x > 7 { //! let y: u32 = another_generic_computation(); //! x += y //! } else { //! x += 1 //! } //! ``` //! //! ## Multiple patterns //! //! ```rust,ignore //! if_chain! { //! if let Foo(y) | Bar(y) | Baz(y) = x; //! let Bubbles(z) | Buttercup(z) | Blossom(z) = y; //! then { do_stuff_with(z) } //! } //! ``` //! //! becomes //! //! ```rust,ignore //! match x { //! Foo(y) | Bar(y) | Baz(y) => match y { //! Bubbles(z) | Buttercup(z) | Blossom(z) => do_stuff_with(z) //! }, //! _ => {} //! } //! ``` //! //! Note that if you use a plain `let`, then `if_chain!` assumes that the //! pattern is *irrefutable* (always matches) and doesn't add a fallback branch. #![cfg_attr(not(test), no_std)] /// Macro for writing nested `if let` expressions. /// /// See the crate documentation for information on how to use this macro. #[macro_export(local_inner_macros)] macro_rules! if_chain { ($($tt:tt)*) => { __if_chain! { @init () $($tt)* } }; } #[doc(hidden)] #[macro_export(local_inner_macros)] macro_rules! __if_chain { // Expand with both a successful case and a fallback (@init ($($tt:tt)*) then { $($then:tt)* } else { $($other:tt)* }) => { __if_chain! { @expand { $($other)* } $($tt)* then { $($then)* } } }; // Expand with no fallback (@init ($($tt:tt)*) then { $($then:tt)* }) => { __if_chain! { @expand {} $($tt)* then { $($then)* } } }; // Munch everything until either of the arms above can be matched. // Munched tokens are placed into `$($tt)*` (@init ($($tt:tt)*) $head:tt $($tail:tt)*) => { __if_chain! { @init ($($tt)* $head) $($tail)* } }; // `let` with a single pattern (@expand { $($other:tt)* } let $pat:pat = $expr:expr; $($tt:tt)+) => { { let $pat = $expr; __if_chain! { @expand { $($other)* } $($tt)+ } } }; // `let` with a single identifier and a type hint (@expand { $($other:tt)* } let $ident:ident: $ty:ty = $expr:expr; $($tt:tt)+) => { { let $ident: $ty = $expr; __if_chain! { @expand { $($other)* } $($tt)+ } } }; // `let` with multiple patterns (@expand { $($other:tt)* } let $pat1:pat | $($pat:pat)|+ = $expr:expr; $($tt:tt)+) => { match $expr { $pat1 | $($pat)|+ => { __if_chain! { @expand { $($other)* } $($tt)+ } } } }; // `if let` with a single pattern (@expand {} if let $pat:pat = $expr:expr; $($tt:tt)+) => { if let $pat = $expr { __if_chain! { @expand {} $($tt)+ } } }; // `if let` with a single pattern and a fallback (@expand { $($other:tt)+ } if let $pat:pat = $expr:expr; $($tt:tt)+) => { if let $pat = $expr { __if_chain! { @expand { $($other)+ } $($tt)+ } } else { $($other)+ } }; // `if let` with multiple matterns and a fallback (if present) (@expand { $($other:tt)* } if let $pat1:pat | $($pat:pat)|+ = $expr:expr; $($tt:tt)+) => { match $expr { $pat1 | $($pat)|+ => { __if_chain! { @expand { $($other)* } $($tt)+ } }, _ => { $($other)* } } }; // `if` with a successful case (@expand {} if $expr:expr; $($tt:tt)+) => { if $expr { __if_chain! { @expand {} $($tt)+ } } }; // `if` with both a successful case and a fallback (@expand { $($other:tt)+ } if $expr:expr; $($tt:tt)+) => { if $expr { __if_chain! { @expand { $($other)+ } $($tt)+ } } else { $($other)+ } }; // Final macro call (@expand { $($other:tt)* } then { $($then:tt)* }) => { $($then)* }; } #[cfg(test)] mod tests { #[test] fn simple() { let x: Option, (u32, u32)>> = Some(Err((41, 42))); let mut success = false; if_chain! { if let Some(y) = x; if let Err(z) = y; let (_, b) = z; if b == 42; then { success = true; } } assert!(success); } #[test] fn empty() { let success; if_chain! { then { success = true; } } assert!(success); } #[test] fn empty_with_else() { let success; if_chain! { then { success = true; } else { unreachable!(); } } assert!(success); } #[test] fn if_let_multiple_patterns() { #[derive(Copy, Clone)] enum Robot { Nano, Biscuit1, Biscuit2 } for &(robot, expected) in &[ (Robot::Nano, false), (Robot::Biscuit1, true), (Robot::Biscuit2, true), ] { let is_biscuit = if_chain! { if let Robot::Biscuit1 | Robot::Biscuit2 = robot; then { true } else { false } }; assert_eq!(is_biscuit, expected); } } #[test] fn let_multiple_patterns() { let x: Result = Ok(42); if_chain! { let Ok(x) | Err(x) = x; then { assert_eq!(x, 42); } else { panic!(); } } } #[test] fn let_type_annotation_patterns() { let mut x = 1; if_chain! { if x > 0; let y: u32 = 2; then { x += y; } else { x += 1; } } assert_eq!(x, 3); } }