spinoso_exception/lib.rs
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198
#![warn(clippy::all)]
#![warn(clippy::pedantic)]
#![warn(clippy::cargo)]
#![allow(unknown_lints)]
#![allow(clippy::manual_let_else)]
#![warn(missing_docs)]
#![warn(missing_debug_implementations)]
#![warn(missing_copy_implementations)]
#![warn(rust_2018_idioms)]
#![warn(rust_2021_compatibility)]
#![warn(trivial_casts, trivial_numeric_casts)]
#![warn(unused_qualifications)]
#![warn(variant_size_differences)]
#![forbid(unsafe_code)]
// Enable feature callouts in generated documentation:
// https://doc.rust-lang.org/beta/unstable-book/language-features/doc-cfg.html
//
// This approach is borrowed from tokio.
#![cfg_attr(docsrs, feature(doc_cfg))]
#![cfg_attr(docsrs, feature(doc_alias))]
//! Built in Ruby exception types.
//!
//! Descendants of class [`Exception`] are used to communicate between
//! [`Kernel#raise`] and `rescue` statements in `begin ... end` blocks.
//! Exception objects carry information about the exception – its type (the
//! exception's class name), an optional descriptive string, and optional
//! traceback information. `Exception` subclasses may add additional information
//! like [`NameError#name`].
//!
//! # Ruby Exception Hierarchy
//!
//! The built-in subclasses of [`Exception`] are:
//!
//! - [`NoMemoryError`]
//! - [`ScriptError`]
//! - [`LoadError`]
//! - [`NotImplementedError`]
//! - [`SyntaxError`]
//! - [`SecurityError`]
//! - [`SignalException`]
//! - [`Interrupt`]
//! - [`StandardError`] — default for `rescue`
//! - [`ArgumentError`]
//! - [`UncaughtThrowError`]
//! - [`EncodingError`]
//! - [`FiberError`]
//! - [`IOError`]
//! - [`EOFError`]
//! - [`IndexError`]
//! - [`KeyError`]
//! - [`StopIteration`]
//! - [`LocalJumpError`]
//! - [`NameError`]
//! - [`NoMethodError`]
//! - [`RangeError`]
//! - [`FloatDomainError`]
//! - [`RegexpError`]
//! - [`RuntimeError`] — default for `raise`
//! - [`FrozenError`]
//! - [`SystemCallError`]
//! - `Errno::*`
//! - [`ThreadError`]
//! - [`TypeError`]
//! - [`ZeroDivisionError`]
//! - [`SystemExit`]
//! - [`SystemStackError`]
//! - `fatal` — impossible to rescue
//!
//! # `no_std`
//!
//! This crate is `no_std` compatible when built without the `std` feature. This
//! crate has a required dependency on [`alloc`].
//!
//! # Crate features
//!
//! All features are enabled by default.
//!
//! - **std** - Enables a dependency on the Rust Standard Library. Activating
//! this feature enables [`std::error::Error`] impls on error types in this
//! crate.
//!
//! [`Exception`]: https://ruby-doc.org/core-3.1.2/Exception.html
//! [`Kernel#raise`]: https://ruby-doc.org/core-3.1.2/Kernel.html#method-i-raise
//! [`NameError#name`]: https://ruby-doc.org/core-3.1.2/NameError.html#method-i-name
//! [`NoMemoryError`]: https://ruby-doc.org/core-3.1.2/NoMemoryError.html
//! [`ScriptError`]: https://ruby-doc.org/core-3.1.2/ScriptError.html
//! [`LoadError`]: https://ruby-doc.org/core-3.1.2/LoadError.html
//! [`NotImplementedError`]: https://ruby-doc.org/core-3.1.2/NotImplementedError.html
//! [`SyntaxError`]: https://ruby-doc.org/core-3.1.2/SyntaxError.html
//! [`SecurityError`]: https://ruby-doc.org/core-3.1.2/SecurityError.html
//! [`SignalException`]: https://ruby-doc.org/core-3.1.2/SignalException.html
//! [`Interrupt`]: https://ruby-doc.org/core-3.1.2/Interrupt.html
//! [`StandardError`]: https://ruby-doc.org/core-3.1.2/StandardError.html
//! [`ArgumentError`]: https://ruby-doc.org/core-3.1.2/ArgumentError.html
//! [`UncaughtThrowError`]: https://ruby-doc.org/core-3.1.2/UncaughtThrowError.html
//! [`EncodingError`]: https://ruby-doc.org/core-3.1.2/EncodingError.html
//! [`FiberError`]: https://ruby-doc.org/core-3.1.2/FiberError.html
//! [`IOError`]: https://ruby-doc.org/core-3.1.2/IOError.html
//! [`EOFError`]: https://ruby-doc.org/core-3.1.2/EOFError.html
//! [`IndexError`]: https://ruby-doc.org/core-3.1.2/IndexError.html
//! [`KeyError`]: https://ruby-doc.org/core-3.1.2/KeyError.html
//! [`StopIteration`]: https://ruby-doc.org/core-3.1.2/StopIteration.html
//! [`LocalJumpError`]: https://ruby-doc.org/core-3.1.2/LocalJumpError.html
//! [`NameError`]: https://ruby-doc.org/core-3.1.2/NameError.html
//! [`NoMethodError`]: https://ruby-doc.org/core-3.1.2/NoMethodError.html
//! [`RangeError`]: https://ruby-doc.org/core-3.1.2/RangeError.html
//! [`FloatDomainError`]: https://ruby-doc.org/core-3.1.2/FloatDomainError.html
//! [`RegexpError`]: https://ruby-doc.org/core-3.1.2/RegexpError.html
//! [`RuntimeError`]: https://ruby-doc.org/core-3.1.2/RuntimeError.html
//! [`FrozenError`]: https://ruby-doc.org/core-3.1.2/FrozenError.html
//! [`SystemCallError`]: https://ruby-doc.org/core-3.1.2/SystemCallError.html
//! [`ThreadError`]: https://ruby-doc.org/core-3.1.2/ThreadError.html
//! [`TypeError`]: https://ruby-doc.org/core-3.1.2/TypeError.html
//! [`ZeroDivisionError`]: https://ruby-doc.org/core-3.1.2/ZeroDivisionError.html
//! [`SystemExit`]: https://ruby-doc.org/core-3.1.2/SystemExit.html
//! [`SystemStackError`]: https://ruby-doc.org/core-3.1.2/SystemStackError.html
#![no_std]
// Ensure code blocks in `README.md` compile
#[cfg(doctest)]
#[doc = include_str!("../README.md")]
mod readme {}
extern crate alloc;
#[cfg(feature = "std")]
extern crate std;
use alloc::borrow::Cow;
pub mod core;
#[doc(inline)]
pub use self::core::*;
/// Polymorphic exception type that corresponds to Ruby's `Exception`.
///
/// This trait unifies all concrete exception types defined in this crate and is
/// [object safe]. This means `RubyException` can be used as a trait object to
/// represent an error type of any set of exception subclasses.
///
/// All types that implement `RubyException` should be `raise`able in an
/// Artichoke Ruby VM.
///
/// # Examples
///
/// ```
/// # use spinoso_exception::*;
/// # struct Array(()); impl Array { pub fn is_frozen(&self) -> bool { true } }
/// fn array_concat(slf: Array, other: Array) -> Result<Array, Box<dyn RubyException>> {
/// if slf.is_frozen() {
/// return Err(Box::new(FrozenError::new()));
/// }
/// Err(Box::new(NotImplementedError::new()))
/// }
/// ```
///
/// [object safe]: https://doc.rust-lang.org/book/ch17-02-trait-objects.html#object-safety-is-required-for-trait-objects
pub trait RubyException {
/// The exception's message.
///
/// # Examples
///
/// ```
/// # use spinoso_exception::*;
/// fn exception_inspect(exc: &dyn RubyException) {
/// let message = exc.message();
/// let message = String::from_utf8_lossy(&message);
/// println!("{} ({})", exc.name(), message);
/// }
/// ```
///
/// # Implementation notes
///
/// This method returns a byte slice since Ruby `String`s are best
/// represented as a [`Vec<u8>`].
///
/// [`Vec<u8>`]: alloc::vec::Vec
fn message(&self) -> Cow<'_, [u8]>;
/// The exception's class name.
///
/// # Examples
///
/// ```
/// # use spinoso_exception::*;
/// fn exception_inspect(exc: &dyn RubyException) {
/// let message = exc.message();
/// let message = String::from_utf8_lossy(&message);
/// println!("{} ({})", exc.name(), message);
/// }
/// ```
fn name(&self) -> Cow<'_, str>;
}
// Assert that `RubyException` is object-safe (i.e. supports dynamic dispatch).
const _: Option<&dyn RubyException> = None;