either-1.6.1/.cargo_vcs_info.json0000644000000001121373051555400123610ustar { "git": { "sha1": "6d3216446d4828d9fa254a6952b40408fbc9c9bd" } } either-1.6.1/.gitignore010066400247370024737000000000241343360064600131770ustar 00000000000000/target /Cargo.lock either-1.6.1/.travis.yml010066400247370024737000000011251371431770400133250ustar 00000000000000language: rust sudo: false # run builds for all the trains (and more) rust: - stable - beta - nightly branches: only: - master # the main build script: - | cargo build --features "${FEATURES}" && cargo test --features "${FEATURES}" && cargo doc --features "${FEATURES}" env: matrix: - FEATURES="" - FEATURES="serde" matrix: include: - rust: 1.12.0 env: FEATURES="" before_script: - | cargo generate-lockfile && cargo update -p serde_json --precise 1.0.0 && cargo update -p serde --precise 1.0.0 either-1.6.1/Cargo.toml0000644000000023151373051555400103660ustar # 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 believe there's an error in this file please file an # issue against the rust-lang/cargo repository. If you're # editing this file be aware that the upstream Cargo.toml # will likely look very different (and much more reasonable) [package] name = "either" version = "1.6.1" authors = ["bluss"] description = "The enum `Either` with variants `Left` and `Right` is a general purpose sum type with two cases.\n" documentation = "https://docs.rs/either/1/" readme = "README-crates.io.md" keywords = ["data-structure", "no_std"] categories = ["data-structures", "no-std"] license = "MIT/Apache-2.0" repository = "https://github.com/bluss/either" [package.metadata.docs.rs] features = ["serde"] [package.metadata.release] no-dev-version = true tag-name = "{{version}}" [dependencies.serde] version = "1.0" features = ["derive"] optional = true [dev-dependencies.serde_json] version = "1.0.0" [features] default = ["use_std"] use_std = [] either-1.6.1/Cargo.toml.orig010066400247370024737000000013121373051450100140710ustar 00000000000000[package] name = "either" version = "1.6.1" authors = ["bluss"] license = "MIT/Apache-2.0" repository = "https://github.com/bluss/either" documentation = "https://docs.rs/either/1/" readme = "README-crates.io.md" description = """ The enum `Either` with variants `Left` and `Right` is a general purpose sum type with two cases. """ keywords = ["data-structure", "no_std"] categories = ["data-structures", "no-std"] [dependencies] serde = { version = "1.0", optional = true, features = ["derive"] } [features] default = ["use_std"] use_std = [] [dev-dependencies] serde_json = "1.0.0" [package.metadata.release] no-dev-version = true tag-name = "{{version}}" [package.metadata.docs.rs] features = ["serde"] either-1.6.1/LICENSE-APACHE010066400247370024737000000251371343360064600131470ustar 00000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License. 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See the License for the specific language governing permissions and limitations under the License. either-1.6.1/LICENSE-MIT010066400247370024737000000020231343360064600126440ustar 00000000000000Copyright (c) 2015 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. either-1.6.1/README-crates.io.md010066400247370024737000000006711343360064600143630ustar 00000000000000The enum `Either` with variants `Left` and `Right` is a general purpose sum type with two cases. Either has methods that are similar to Option and Result, and it also implements traits like `Iterator`. Includes macros `try_left!()` and `try_right!()` to use for short-circuiting logic, similar to how the `?` operator is used with `Result`. Note that `Either` is general purpose. For describing success or error, use the regular `Result`. either-1.6.1/README.rst010066400247370024737000000053421373051455200127060ustar 00000000000000 Either ====== The enum ``Either`` with variants ``Left`` and ``Right`` and trait implementations including Iterator, Read, Write. Either has methods that are similar to Option and Result. Includes convenience macros ``try_left!()`` and ``try_right!()`` to use for short-circuiting logic. Please read the `API documentation here`__ __ https://docs.rs/either/ |build_status|_ |crates|_ .. |build_status| image:: https://travis-ci.org/bluss/either.svg?branch=master .. _build_status: https://travis-ci.org/bluss/either .. |crates| image:: http://meritbadge.herokuapp.com/either .. _crates: https://crates.io/crates/either How to use with cargo:: [dependencies] either = "1.6" Recent Changes -------------- - 1.6.1 - Add new methods ``.expect_left()``, ``.unwrap_left()``, and equivalents on the right, by @spenserblack (#51) - 1.6.0 - Add new modules ``serde_untagged`` and ``serde_untagged_optional`` to customize how ``Either`` fields are serialized in other types, by @MikailBag (#49) - 1.5.3 - Add new method ``.map()`` for ``Either`` by @nvzqz (#40). - 1.5.2 - Add new methods ``.left_or()``, ``.left_or_default()``, ``.left_or_else()``, and equivalents on the right, by @DCjanus (#36) - 1.5.1 - Add ``AsRef`` and ``AsMut`` implementations for common unsized types: ``str``, ``[T]``, ``CStr``, ``OsStr``, and ``Path``, by @mexus (#29) - 1.5.0 - Add new methods ``.factor_first()``, ``.factor_second()`` and ``.into_inner()`` by @mathstuf (#19) - 1.4.0 - Add inherent method ``.into_iter()`` by @cuviper (#12) - 1.3.0 - Add opt-in serde support by @hcpl - 1.2.0 - Add method ``.either_with()`` by @Twey (#13) - 1.1.0 - Add methods ``left_and_then``, ``right_and_then`` by @rampantmonkey - Include license files in the repository and released crate - 1.0.3 - Add crate categories - 1.0.2 - Forward more ``Iterator`` methods - Implement ``Extend`` for ``Either`` if ``L, R`` do. - 1.0.1 - Fix ``Iterator`` impl for ``Either`` to forward ``.fold()``. - 1.0.0 - Add default crate feature ``use_std`` so that you can opt out of linking to std. - 0.1.7 - Add methods ``.map_left()``, ``.map_right()`` and ``.either()``. - Add more documentation - 0.1.3 - Implement Display, Error - 0.1.2 - Add macros ``try_left!`` and ``try_right!``. - 0.1.1 - Implement Deref, DerefMut - 0.1.0 - Initial release - Support Iterator, Read, Write License ------- Dual-licensed to be compatible with the Rust project. Licensed under the Apache License, Version 2.0 http://www.apache.org/licenses/LICENSE-2.0 or the MIT license http://opensource.org/licenses/MIT, at your option. This file may not be copied, modified, or distributed except according to those terms. either-1.6.1/src/lib.rs010066400247370024737000000715701373051413400131240ustar 00000000000000//! The enum [`Either`] with variants `Left` and `Right` is a general purpose //! sum type with two cases. //! //! [`Either`]: enum.Either.html //! //! **Crate features:** //! //! * `"use_std"` //! Enabled by default. Disable to make the library `#![no_std]`. //! //! * `"serde"` //! Disabled by default. Enable to `#[derive(Serialize, Deserialize)]` for `Either` //! #![doc(html_root_url = "https://docs.rs/either/1/")] #![cfg_attr(all(not(test), not(feature = "use_std")), no_std)] #[cfg(all(not(test), not(feature = "use_std")))] extern crate core as std; #[cfg(feature = "serde")] #[macro_use] extern crate serde; #[cfg(feature = "serde")] pub mod serde_untagged; #[cfg(feature = "serde")] pub mod serde_untagged_optional; use std::convert::{AsMut, AsRef}; use std::fmt; use std::iter; use std::ops::Deref; use std::ops::DerefMut; #[cfg(any(test, feature = "use_std"))] use std::error::Error; #[cfg(any(test, feature = "use_std"))] use std::io::{self, BufRead, Read, Write}; pub use Either::{Left, Right}; /// The enum `Either` with variants `Left` and `Right` is a general purpose /// sum type with two cases. /// /// The `Either` type is symmetric and treats its variants the same way, without /// preference. /// (For representing success or error, use the regular `Result` enum instead.) #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))] #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] pub enum Either { /// A value of type `L`. Left(L), /// A value of type `R`. Right(R), } macro_rules! either { ($value:expr, $pattern:pat => $result:expr) => { match $value { Either::Left($pattern) => $result, Either::Right($pattern) => $result, } }; } /// Macro for unwrapping the left side of an `Either`, which fails early /// with the opposite side. Can only be used in functions that return /// `Either` because of the early return of `Right` that it provides. /// /// See also `try_right!` for its dual, which applies the same just to the /// right side. /// /// # Example /// /// ``` /// #[macro_use] extern crate either; /// use either::{Either, Left, Right}; /// /// fn twice(wrapper: Either) -> Either { /// let value = try_left!(wrapper); /// Left(value * 2) /// } /// /// fn main() { /// assert_eq!(twice(Left(2)), Left(4)); /// assert_eq!(twice(Right("ups")), Right("ups")); /// } /// ``` #[macro_export] macro_rules! try_left { ($expr:expr) => { match $expr { $crate::Left(val) => val, $crate::Right(err) => return $crate::Right(::std::convert::From::from(err)), } }; } /// Dual to `try_left!`, see its documentation for more information. #[macro_export] macro_rules! try_right { ($expr:expr) => { match $expr { $crate::Left(err) => return $crate::Left(::std::convert::From::from(err)), $crate::Right(val) => val, } }; } impl Either { /// Return true if the value is the `Left` variant. /// /// ``` /// use either::*; /// /// let values = [Left(1), Right("the right value")]; /// assert_eq!(values[0].is_left(), true); /// assert_eq!(values[1].is_left(), false); /// ``` pub fn is_left(&self) -> bool { match *self { Left(_) => true, Right(_) => false, } } /// Return true if the value is the `Right` variant. /// /// ``` /// use either::*; /// /// let values = [Left(1), Right("the right value")]; /// assert_eq!(values[0].is_right(), false); /// assert_eq!(values[1].is_right(), true); /// ``` pub fn is_right(&self) -> bool { !self.is_left() } /// Convert the left side of `Either` to an `Option`. /// /// ``` /// use either::*; /// /// let left: Either<_, ()> = Left("some value"); /// assert_eq!(left.left(), Some("some value")); /// /// let right: Either<(), _> = Right(321); /// assert_eq!(right.left(), None); /// ``` pub fn left(self) -> Option { match self { Left(l) => Some(l), Right(_) => None, } } /// Convert the right side of `Either` to an `Option`. /// /// ``` /// use either::*; /// /// let left: Either<_, ()> = Left("some value"); /// assert_eq!(left.right(), None); /// /// let right: Either<(), _> = Right(321); /// assert_eq!(right.right(), Some(321)); /// ``` pub fn right(self) -> Option { match self { Left(_) => None, Right(r) => Some(r), } } /// Convert `&Either` to `Either<&L, &R>`. /// /// ``` /// use either::*; /// /// let left: Either<_, ()> = Left("some value"); /// assert_eq!(left.as_ref(), Left(&"some value")); /// /// let right: Either<(), _> = Right("some value"); /// assert_eq!(right.as_ref(), Right(&"some value")); /// ``` pub fn as_ref(&self) -> Either<&L, &R> { match *self { Left(ref inner) => Left(inner), Right(ref inner) => Right(inner), } } /// Convert `&mut Either` to `Either<&mut L, &mut R>`. /// /// ``` /// use either::*; /// /// fn mutate_left(value: &mut Either) { /// if let Some(l) = value.as_mut().left() { /// *l = 999; /// } /// } /// /// let mut left = Left(123); /// let mut right = Right(123); /// mutate_left(&mut left); /// mutate_left(&mut right); /// assert_eq!(left, Left(999)); /// assert_eq!(right, Right(123)); /// ``` pub fn as_mut(&mut self) -> Either<&mut L, &mut R> { match *self { Left(ref mut inner) => Left(inner), Right(ref mut inner) => Right(inner), } } /// Convert `Either` to `Either`. /// /// ``` /// use either::*; /// /// let left: Either<_, ()> = Left(123); /// assert_eq!(left.flip(), Right(123)); /// /// let right: Either<(), _> = Right("some value"); /// assert_eq!(right.flip(), Left("some value")); /// ``` pub fn flip(self) -> Either { match self { Left(l) => Right(l), Right(r) => Left(r), } } /// Apply the function `f` on the value in the `Left` variant if it is present rewrapping the /// result in `Left`. /// /// ``` /// use either::*; /// /// let left: Either<_, u32> = Left(123); /// assert_eq!(left.map_left(|x| x * 2), Left(246)); /// /// let right: Either = Right(123); /// assert_eq!(right.map_left(|x| x * 2), Right(123)); /// ``` pub fn map_left(self, f: F) -> Either where F: FnOnce(L) -> M, { match self { Left(l) => Left(f(l)), Right(r) => Right(r), } } /// Apply the function `f` on the value in the `Right` variant if it is present rewrapping the /// result in `Right`. /// /// ``` /// use either::*; /// /// let left: Either<_, u32> = Left(123); /// assert_eq!(left.map_right(|x| x * 2), Left(123)); /// /// let right: Either = Right(123); /// assert_eq!(right.map_right(|x| x * 2), Right(246)); /// ``` pub fn map_right(self, f: F) -> Either where F: FnOnce(R) -> S, { match self { Left(l) => Left(l), Right(r) => Right(f(r)), } } /// Apply one of two functions depending on contents, unifying their result. If the value is /// `Left(L)` then the first function `f` is applied; if it is `Right(R)` then the second /// function `g` is applied. /// /// ``` /// use either::*; /// /// fn square(n: u32) -> i32 { (n * n) as i32 } /// fn negate(n: i32) -> i32 { -n } /// /// let left: Either = Left(4); /// assert_eq!(left.either(square, negate), 16); /// /// let right: Either = Right(-4); /// assert_eq!(right.either(square, negate), 4); /// ``` pub fn either(self, f: F, g: G) -> T where F: FnOnce(L) -> T, G: FnOnce(R) -> T, { match self { Left(l) => f(l), Right(r) => g(r), } } /// Like `either`, but provide some context to whichever of the /// functions ends up being called. /// /// ``` /// // In this example, the context is a mutable reference /// use either::*; /// /// let mut result = Vec::new(); /// /// let values = vec![Left(2), Right(2.7)]; /// /// for value in values { /// value.either_with(&mut result, /// |ctx, integer| ctx.push(integer), /// |ctx, real| ctx.push(f64::round(real) as i32)); /// } /// /// assert_eq!(result, vec![2, 3]); /// ``` pub fn either_with(self, ctx: Ctx, f: F, g: G) -> T where F: FnOnce(Ctx, L) -> T, G: FnOnce(Ctx, R) -> T, { match self { Left(l) => f(ctx, l), Right(r) => g(ctx, r), } } /// Apply the function `f` on the value in the `Left` variant if it is present. /// /// ``` /// use either::*; /// /// let left: Either<_, u32> = Left(123); /// assert_eq!(left.left_and_then::<_,()>(|x| Right(x * 2)), Right(246)); /// /// let right: Either = Right(123); /// assert_eq!(right.left_and_then(|x| Right::<(), _>(x * 2)), Right(123)); /// ``` pub fn left_and_then(self, f: F) -> Either where F: FnOnce(L) -> Either, { match self { Left(l) => f(l), Right(r) => Right(r), } } /// Apply the function `f` on the value in the `Right` variant if it is present. /// /// ``` /// use either::*; /// /// let left: Either<_, u32> = Left(123); /// assert_eq!(left.right_and_then(|x| Right(x * 2)), Left(123)); /// /// let right: Either = Right(123); /// assert_eq!(right.right_and_then(|x| Right(x * 2)), Right(246)); /// ``` pub fn right_and_then(self, f: F) -> Either where F: FnOnce(R) -> Either, { match self { Left(l) => Left(l), Right(r) => f(r), } } /// Convert the inner value to an iterator. /// /// ``` /// use either::*; /// /// let left: Either<_, Vec> = Left(vec![1, 2, 3, 4, 5]); /// let mut right: Either, _> = Right(vec![]); /// right.extend(left.into_iter()); /// assert_eq!(right, Right(vec![1, 2, 3, 4, 5])); /// ``` pub fn into_iter(self) -> Either where L: IntoIterator, R: IntoIterator, { match self { Left(l) => Left(l.into_iter()), Right(r) => Right(r.into_iter()), } } /// Return left value or given value /// /// Arguments passed to `left_or` are eagerly evaluated; if you are passing /// the result of a function call, it is recommended to use [`left_or_else`], /// which is lazily evaluated. /// /// [`left_or_else`]: #method.left_or_else /// /// # Examples /// /// ``` /// # use either::*; /// let left: Either<&str, &str> = Left("left"); /// assert_eq!(left.left_or("foo"), "left"); /// /// let right: Either<&str, &str> = Right("right"); /// assert_eq!(right.left_or("left"), "left"); /// ``` pub fn left_or(self, other: L) -> L { match self { Either::Left(l) => l, Either::Right(_) => other, } } /// Return left or a default /// /// # Examples /// /// ``` /// # use either::*; /// let left: Either = Left("left".to_string()); /// assert_eq!(left.left_or_default(), "left"); /// /// let right: Either = Right(42); /// assert_eq!(right.left_or_default(), String::default()); /// ``` pub fn left_or_default(self) -> L where L: Default, { match self { Either::Left(l) => l, Either::Right(_) => L::default(), } } /// Returns left value or computes it from a closure /// /// # Examples /// /// ``` /// # use either::*; /// let left: Either = Left("3".to_string()); /// assert_eq!(left.left_or_else(|_| unreachable!()), "3"); /// /// let right: Either = Right(3); /// assert_eq!(right.left_or_else(|x| x.to_string()), "3"); /// ``` pub fn left_or_else(self, f: F) -> L where F: FnOnce(R) -> L, { match self { Either::Left(l) => l, Either::Right(r) => f(r), } } /// Return right value or given value /// /// Arguments passed to `right_or` are eagerly evaluated; if you are passing /// the result of a function call, it is recommended to use [`right_or_else`], /// which is lazily evaluated. /// /// [`right_or_else`]: #method.right_or_else /// /// # Examples /// /// ``` /// # use either::*; /// let right: Either<&str, &str> = Right("right"); /// assert_eq!(right.right_or("foo"), "right"); /// /// let left: Either<&str, &str> = Left("left"); /// assert_eq!(left.right_or("right"), "right"); /// ``` pub fn right_or(self, other: R) -> R { match self { Either::Left(_) => other, Either::Right(r) => r, } } /// Return right or a default /// /// # Examples /// /// ``` /// # use either::*; /// let left: Either = Left("left".to_string()); /// assert_eq!(left.right_or_default(), u32::default()); /// /// let right: Either = Right(42); /// assert_eq!(right.right_or_default(), 42); /// ``` pub fn right_or_default(self) -> R where R: Default, { match self { Either::Left(_) => R::default(), Either::Right(r) => r, } } /// Returns right value or computes it from a closure /// /// # Examples /// /// ``` /// # use either::*; /// let left: Either = Left("3".to_string()); /// assert_eq!(left.right_or_else(|x| x.parse().unwrap()), 3); /// /// let right: Either = Right(3); /// assert_eq!(right.right_or_else(|_| unreachable!()), 3); /// ``` pub fn right_or_else(self, f: F) -> R where F: FnOnce(L) -> R, { match self { Either::Left(l) => f(l), Either::Right(r) => r, } } /// Returns the left value /// /// # Examples /// /// ``` /// # use either::*; /// let left: Either<_, ()> = Left(3); /// assert_eq!(left.unwrap_left(), 3); /// ``` /// /// # Panics /// /// When `Either` is a `Right` value /// /// ```should_panic /// # use either::*; /// let right: Either<(), _> = Right(3); /// right.unwrap_left(); /// ``` pub fn unwrap_left(self) -> L where R: std::fmt::Debug, { match self { Either::Left(l) => l, Either::Right(r) => { panic!("called `Either::unwrap_left()` on a `Right` value: {:?}", r) } } } /// Returns the right value /// /// # Examples /// /// ``` /// # use either::*; /// let right: Either<(), _> = Right(3); /// assert_eq!(right.unwrap_right(), 3); /// ``` /// /// # Panics /// /// When `Either` is a `Left` value /// /// ```should_panic /// # use either::*; /// let left: Either<_, ()> = Left(3); /// left.unwrap_right(); /// ``` pub fn unwrap_right(self) -> R where L: std::fmt::Debug, { match self { Either::Right(r) => r, Either::Left(l) => panic!("called `Either::unwrap_right()` on a `Left` value: {:?}", l), } } /// Returns the left value /// /// # Examples /// /// ``` /// # use either::*; /// let left: Either<_, ()> = Left(3); /// assert_eq!(left.expect_left("value was Right"), 3); /// ``` /// /// # Panics /// /// When `Either` is a `Right` value /// /// ```should_panic /// # use either::*; /// let right: Either<(), _> = Right(3); /// right.expect_left("value was Right"); /// ``` pub fn expect_left(self, msg: &str) -> L where R: std::fmt::Debug, { match self { Either::Left(l) => l, Either::Right(r) => panic!("{}: {:?}", msg, r), } } /// Returns the right value /// /// # Examples /// /// ``` /// # use either::*; /// let right: Either<(), _> = Right(3); /// assert_eq!(right.expect_right("value was Left"), 3); /// ``` /// /// # Panics /// /// When `Either` is a `Left` value /// /// ```should_panic /// # use either::*; /// let left: Either<_, ()> = Left(3); /// left.expect_right("value was Right"); /// ``` pub fn expect_right(self, msg: &str) -> R where L: std::fmt::Debug, { match self { Either::Right(r) => r, Either::Left(l) => panic!("{}: {:?}", msg, l), } } } impl Either<(T, L), (T, R)> { /// Factor out a homogeneous type from an either of pairs. /// /// Here, the homogeneous type is the first element of the pairs. /// /// ``` /// use either::*; /// let left: Either<_, (u32, String)> = Left((123, vec![0])); /// assert_eq!(left.factor_first().0, 123); /// /// let right: Either<(u32, Vec), _> = Right((123, String::new())); /// assert_eq!(right.factor_first().0, 123); /// ``` pub fn factor_first(self) -> (T, Either) { match self { Left((t, l)) => (t, Left(l)), Right((t, r)) => (t, Right(r)), } } } impl Either<(L, T), (R, T)> { /// Factor out a homogeneous type from an either of pairs. /// /// Here, the homogeneous type is the second element of the pairs. /// /// ``` /// use either::*; /// let left: Either<_, (String, u32)> = Left((vec![0], 123)); /// assert_eq!(left.factor_second().1, 123); /// /// let right: Either<(Vec, u32), _> = Right((String::new(), 123)); /// assert_eq!(right.factor_second().1, 123); /// ``` pub fn factor_second(self) -> (Either, T) { match self { Left((l, t)) => (Left(l), t), Right((r, t)) => (Right(r), t), } } } impl Either { /// Extract the value of an either over two equivalent types. /// /// ``` /// use either::*; /// /// let left: Either<_, u32> = Left(123); /// assert_eq!(left.into_inner(), 123); /// /// let right: Either = Right(123); /// assert_eq!(right.into_inner(), 123); /// ``` pub fn into_inner(self) -> T { either!(self, inner => inner) } /// Map `f` over the contained value and return the result in the /// corresponding variant. /// /// ``` /// use either::*; /// /// let value: Either<_, i32> = Right(42); /// /// let other = value.map(|x| x * 2); /// assert_eq!(other, Right(84)); /// ``` pub fn map(self, f: F) -> Either where F: FnOnce(T) -> M, { match self { Left(l) => Left(f(l)), Right(r) => Right(f(r)), } } } /// Convert from `Result` to `Either` with `Ok => Right` and `Err => Left`. impl From> for Either { fn from(r: Result) -> Self { match r { Err(e) => Left(e), Ok(o) => Right(o), } } } /// Convert from `Either` to `Result` with `Right => Ok` and `Left => Err`. impl Into> for Either { fn into(self) -> Result { match self { Left(l) => Err(l), Right(r) => Ok(r), } } } impl Extend for Either where L: Extend, R: Extend, { fn extend(&mut self, iter: T) where T: IntoIterator, { either!(*self, ref mut inner => inner.extend(iter)) } } /// `Either` is an iterator if both `L` and `R` are iterators. impl Iterator for Either where L: Iterator, R: Iterator, { type Item = L::Item; fn next(&mut self) -> Option { either!(*self, ref mut inner => inner.next()) } fn size_hint(&self) -> (usize, Option) { either!(*self, ref inner => inner.size_hint()) } fn fold(self, init: Acc, f: G) -> Acc where G: FnMut(Acc, Self::Item) -> Acc, { either!(self, inner => inner.fold(init, f)) } fn count(self) -> usize { either!(self, inner => inner.count()) } fn last(self) -> Option { either!(self, inner => inner.last()) } fn nth(&mut self, n: usize) -> Option { either!(*self, ref mut inner => inner.nth(n)) } fn collect(self) -> B where B: iter::FromIterator, { either!(self, inner => inner.collect()) } fn all(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool, { either!(*self, ref mut inner => inner.all(f)) } } impl DoubleEndedIterator for Either where L: DoubleEndedIterator, R: DoubleEndedIterator, { fn next_back(&mut self) -> Option { either!(*self, ref mut inner => inner.next_back()) } } impl ExactSizeIterator for Either where L: ExactSizeIterator, R: ExactSizeIterator, { } #[cfg(any(test, feature = "use_std"))] /// `Either` implements `Read` if both `L` and `R` do. /// /// Requires crate feature `"use_std"` impl Read for Either where L: Read, R: Read, { fn read(&mut self, buf: &mut [u8]) -> io::Result { either!(*self, ref mut inner => inner.read(buf)) } fn read_to_end(&mut self, buf: &mut Vec) -> io::Result { either!(*self, ref mut inner => inner.read_to_end(buf)) } } #[cfg(any(test, feature = "use_std"))] /// Requires crate feature `"use_std"` impl BufRead for Either where L: BufRead, R: BufRead, { fn fill_buf(&mut self) -> io::Result<&[u8]> { either!(*self, ref mut inner => inner.fill_buf()) } fn consume(&mut self, amt: usize) { either!(*self, ref mut inner => inner.consume(amt)) } } #[cfg(any(test, feature = "use_std"))] /// `Either` implements `Write` if both `L` and `R` do. /// /// Requires crate feature `"use_std"` impl Write for Either where L: Write, R: Write, { fn write(&mut self, buf: &[u8]) -> io::Result { either!(*self, ref mut inner => inner.write(buf)) } fn flush(&mut self) -> io::Result<()> { either!(*self, ref mut inner => inner.flush()) } } impl AsRef for Either where L: AsRef, R: AsRef, { fn as_ref(&self) -> &Target { either!(*self, ref inner => inner.as_ref()) } } macro_rules! impl_specific_ref_and_mut { ($t:ty, $($attr:meta),* ) => { $(#[$attr])* impl AsRef<$t> for Either where L: AsRef<$t>, R: AsRef<$t> { fn as_ref(&self) -> &$t { either!(*self, ref inner => inner.as_ref()) } } $(#[$attr])* impl AsMut<$t> for Either where L: AsMut<$t>, R: AsMut<$t> { fn as_mut(&mut self) -> &mut $t { either!(*self, ref mut inner => inner.as_mut()) } } }; } impl_specific_ref_and_mut!(str,); impl_specific_ref_and_mut!( ::std::path::Path, cfg(feature = "use_std"), doc = "Requires crate feature `use_std`." ); impl_specific_ref_and_mut!( ::std::ffi::OsStr, cfg(feature = "use_std"), doc = "Requires crate feature `use_std`." ); impl_specific_ref_and_mut!( ::std::ffi::CStr, cfg(feature = "use_std"), doc = "Requires crate feature `use_std`." ); impl AsRef<[Target]> for Either where L: AsRef<[Target]>, R: AsRef<[Target]>, { fn as_ref(&self) -> &[Target] { either!(*self, ref inner => inner.as_ref()) } } impl AsMut for Either where L: AsMut, R: AsMut, { fn as_mut(&mut self) -> &mut Target { either!(*self, ref mut inner => inner.as_mut()) } } impl AsMut<[Target]> for Either where L: AsMut<[Target]>, R: AsMut<[Target]>, { fn as_mut(&mut self) -> &mut [Target] { either!(*self, ref mut inner => inner.as_mut()) } } impl Deref for Either where L: Deref, R: Deref, { type Target = L::Target; fn deref(&self) -> &Self::Target { either!(*self, ref inner => &*inner) } } impl DerefMut for Either where L: DerefMut, R: DerefMut, { fn deref_mut(&mut self) -> &mut Self::Target { either!(*self, ref mut inner => &mut *inner) } } #[cfg(any(test, feature = "use_std"))] /// `Either` implements `Error` if *both* `L` and `R` implement it. impl Error for Either where L: Error, R: Error, { #[allow(deprecated)] fn description(&self) -> &str { either!(*self, ref inner => inner.description()) } #[allow(deprecated)] #[allow(unknown_lints, bare_trait_objects)] fn cause(&self) -> Option<&Error> { either!(*self, ref inner => inner.cause()) } } impl fmt::Display for Either where L: fmt::Display, R: fmt::Display, { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { either!(*self, ref inner => inner.fmt(f)) } } #[test] fn basic() { let mut e = Left(2); let r = Right(2); assert_eq!(e, Left(2)); e = r; assert_eq!(e, Right(2)); assert_eq!(e.left(), None); assert_eq!(e.right(), Some(2)); assert_eq!(e.as_ref().right(), Some(&2)); assert_eq!(e.as_mut().right(), Some(&mut 2)); } #[test] fn macros() { fn a() -> Either { let x: u32 = try_left!(Right(1337u32)); Left(x * 2) } assert_eq!(a(), Right(1337)); fn b() -> Either { Right(try_right!(Left("foo bar"))) } assert_eq!(b(), Left(String::from("foo bar"))); } #[test] fn deref() { fn is_str(_: &str) {} let value: Either = Left(String::from("test")); is_str(&*value); } #[test] fn iter() { let x = 3; let mut iter = match x { 3 => Left(0..10), _ => Right(17..), }; assert_eq!(iter.next(), Some(0)); assert_eq!(iter.count(), 9); } #[test] fn read_write() { use std::io; let use_stdio = false; let mockdata = [0xff; 256]; let mut reader = if use_stdio { Left(io::stdin()) } else { Right(&mockdata[..]) }; let mut buf = [0u8; 16]; assert_eq!(reader.read(&mut buf).unwrap(), buf.len()); assert_eq!(&buf, &mockdata[..buf.len()]); let mut mockbuf = [0u8; 256]; let mut writer = if use_stdio { Left(io::stdout()) } else { Right(&mut mockbuf[..]) }; let buf = [1u8; 16]; assert_eq!(writer.write(&buf).unwrap(), buf.len()); } #[test] #[allow(deprecated)] fn error() { let invalid_utf8 = b"\xff"; let res = if let Err(error) = ::std::str::from_utf8(invalid_utf8) { Err(Left(error)) } else if let Err(error) = "x".parse::() { Err(Right(error)) } else { Ok(()) }; assert!(res.is_err()); res.unwrap_err().description(); // make sure this can be called } /// A helper macro to check if AsRef and AsMut are implemented for a given type. macro_rules! check_t { ($t:ty) => {{ fn check_ref>() {} fn propagate_ref, T2: AsRef<$t>>() { check_ref::>() } fn check_mut>() {} fn propagate_mut, T2: AsMut<$t>>() { check_mut::>() } }}; } // This "unused" method is here to ensure that compilation doesn't fail on given types. fn _unsized_ref_propagation() { check_t!(str); fn check_array_ref, Item>() {} fn check_array_mut, Item>() {} fn propagate_array_ref, T2: AsRef<[Item]>, Item>() { check_array_ref::, _>() } fn propagate_array_mut, T2: AsMut<[Item]>, Item>() { check_array_mut::, _>() } } // This "unused" method is here to ensure that compilation doesn't fail on given types. #[cfg(feature = "use_std")] fn _unsized_std_propagation() { check_t!(::std::path::Path); check_t!(::std::ffi::OsStr); check_t!(::std::ffi::CStr); } either-1.6.1/src/serde_untagged.rs010066400247370024737000000041201371433670500153310ustar 00000000000000//! Untagged serialization/deserialization support for Either. //! //! `Either` uses default, externally-tagged representation. //! However, sometimes it is useful to support several alternative types. //! For example, we may have a field which is generally Map //! but in typical cases Vec would suffice, too. //! //! ```rust //! #[macro_use] //! extern crate serde; //! // or `use serde::{Serialize, Deserialize};` in newer rust versions. //! //! # fn main() -> Result<(), Box> { //! use either::Either; //! use std::collections::HashMap; //! //! #[derive(Serialize, Deserialize, Debug)] //! #[serde(transparent)] //! struct IntOrString { //! #[serde(with = "either::serde_untagged")] //! inner: Either, HashMap> //! }; //! //! // serialization //! let data = IntOrString { //! inner: Either::Left(vec!["Hello".to_string()]) //! }; //! // notice: no tags are emitted. //! assert_eq!(serde_json::to_string(&data)?, r#"["Hello"]"#); //! //! // deserialization //! let data: IntOrString = serde_json::from_str( //! r#"{"a": 0, "b": 14}"# //! )?; //! println!("found {:?}", data); //! # Ok(()) //! # } //! ``` use serde::{Deserialize, Deserializer, Serialize, Serializer}; #[derive(Serialize, Deserialize)] #[serde(untagged)] enum Either { Left(L), Right(R), } pub fn serialize(this: &super::Either, serializer: S) -> Result where S: Serializer, L: Serialize, R: Serialize, { let untagged = match this { &super::Either::Left(ref left) => Either::Left(left), &super::Either::Right(ref right) => Either::Right(right), }; untagged.serialize(serializer) } pub fn deserialize<'de, L, R, D>(deserializer: D) -> Result, D::Error> where D: Deserializer<'de>, L: Deserialize<'de>, R: Deserialize<'de>, { match Either::deserialize(deserializer) { Ok(Either::Left(left)) => Ok(super::Either::Left(left)), Ok(Either::Right(right)) => Ok(super::Either::Right(right)), Err(error) => Err(error), } } either-1.6.1/src/serde_untagged_optional.rs010066400247370024737000000043571371433667300172560ustar 00000000000000//! Untagged serialization/deserialization support for Option>. //! //! `Either` uses default, externally-tagged representation. //! However, sometimes it is useful to support several alternative types. //! For example, we may have a field which is generally Map //! but in typical cases Vec would suffice, too. //! //! ```rust //! #[macro_use] //! extern crate serde; //! // or `use serde::{Serialize, Deserialize};` in newer rust versions. //! //! # fn main() -> Result<(), Box> { //! use either::Either; //! use std::collections::HashMap; //! //! #[derive(Serialize, Deserialize, Debug)] //! #[serde(transparent)] //! struct IntOrString { //! #[serde(with = "either::serde_untagged_optional")] //! inner: Option, HashMap>> //! }; //! //! // serialization //! let data = IntOrString { //! inner: Some(Either::Left(vec!["Hello".to_string()])) //! }; //! // notice: no tags are emitted. //! assert_eq!(serde_json::to_string(&data)?, r#"["Hello"]"#); //! //! // deserialization //! let data: IntOrString = serde_json::from_str( //! r#"{"a": 0, "b": 14}"# //! )?; //! println!("found {:?}", data); //! # Ok(()) //! # } //! ``` use serde::{Deserialize, Deserializer, Serialize, Serializer}; #[derive(Serialize, Deserialize)] #[serde(untagged)] enum Either { Left(L), Right(R), } pub fn serialize( this: &Option>, serializer: S, ) -> Result where S: Serializer, L: Serialize, R: Serialize, { let untagged = match this { &Some(super::Either::Left(ref left)) => Some(Either::Left(left)), &Some(super::Either::Right(ref right)) => Some(Either::Right(right)), &None => None, }; untagged.serialize(serializer) } pub fn deserialize<'de, L, R, D>(deserializer: D) -> Result>, D::Error> where D: Deserializer<'de>, L: Deserialize<'de>, R: Deserialize<'de>, { match Option::deserialize(deserializer) { Ok(Some(Either::Left(left))) => Ok(Some(super::Either::Left(left))), Ok(Some(Either::Right(right))) => Ok(Some(super::Either::Right(right))), Ok(None) => Ok(None), Err(error) => Err(error), } }