+
<p align="center">
<img src="https://raw.github.com/pest-parser/pest/master/pest-logo.svg?sanitize=true" width="80%"/>
</p>
# pest. The Elegant Parser
-[](https://gitter.im/dragostis/pest?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[](https://pest-parser.github.io/book)
+[](https://gitter.im/pest-parser/pest?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[](https://pest.rs/book)
[](https://docs.rs/pest)
-[](https://travis-ci.org/pest-parser/pest)
+[](https://github.com/pest-parser/pest/actions/workflows/ci.yml)
[](https://codecov.io/gh/pest-parser/pest)
+<a href="https://blog.rust-lang.org/2021/11/01/Rust-1.56.1.html"><img alt="Rustc Version 1.56.1+" src="https://img.shields.io/badge/rustc-1.56.1%2B-lightgrey.svg"/></a>
+
[](https://crates.io/crates/pest)
[](https://crates.io/crates/pest)
* API reference on [docs.rs]
* play with grammars and share them on our [fiddle]
-* leave feedback, ask questions, or greet us on [Gitter]
+* find previous common questions answered or ask questions on [GitHub Discussions]
+* leave feedback, ask questions, or greet us on [Gitter] or [Discord]
-[book]: https://pest-parser.github.io/book
+[book]: https://pest.rs/book
[docs.rs]: https://docs.rs/pest
-[fiddle]: https://pest-parser.github.io/#editor
-[Gitter]: https://gitter.im/dragostis/pest
+[fiddle]: https://pest.rs/#editor
+[Gitter]: https://gitter.im/pest-parser/pest
+[Discord]: https://discord.gg/XEGACtWpT2
+[GitHub Discussions]: https://github.com/pest-parser/pest/discussions
## Example
-The following is an example of a grammar for a list of alpha-numeric identifiers
-where the first identifier does not start with a digit:
+The following is an example of a grammar for a list of alphanumeric identifiers
+where all identifiers don't start with a digit:
```rust
alpha = { 'a'..'z' | 'A'..'Z' }
digit = { '0'..'9' }
-ident = { (alpha | digit)+ }
+ident = { !digit ~ (alpha | digit)+ }
-ident_list = _{ !digit ~ ident ~ (" " ~ ident)+ }
+ident_list = _{ ident ~ (" " ~ ident)* }
// ^
// ident_list rule is silent which means it produces no tokens
```
= expected ident', src/main.rs:12
```
+These error messages can be obtained from their default `Display` implementation,
+e.g. `panic!("{}", parser_result.unwrap_err())` or `println!("{}", e)`.
+
## Pairs API
The grammar can be used to derive a `Parser` implementation automatically.
// Because ident_list is silent, the iterator will contain idents
for pair in pairs {
-
- let span = pair.clone().into_span();
// A pair is a combination of the rule which matched and a span of input
println!("Rule: {:?}", pair.as_rule());
- println!("Span: {:?}", span);
- println!("Text: {}", span.as_str());
+ println!("Span: {:?}", pair.as_span());
+ println!("Text: {}", pair.as_str());
// A pair can be converted to an iterator of the tokens which make it up:
for inner_pair in pair.into_inner() {
- let inner_span = inner_pair.clone().into_span();
match inner_pair.as_rule() {
- Rule::alpha => println!("Letter: {}", inner_span.as_str()),
- Rule::digit => println!("Digit: {}", inner_span.as_str()),
+ Rule::alpha => println!("Letter: {}", inner_pair.as_str()),
+ Rule::digit => println!("Digit: {}", inner_pair.as_str()),
_ => unreachable!()
};
}
Digit: 2
```
+### Defining multiple parsers in a single file
+The current automatic `Parser` derivation will produce the `Rule` enum
+which would have name conflicts if one tried to define multiple such structs
+that automatically derive `Parser`. One possible way around it is to put each
+parser struct in a separate namespace:
+
+```rust
+mod a {
+ #[derive(Parser)]
+ #[grammar = "a.pest"]
+ pub struct ParserA;
+}
+mod b {
+ #[derive(Parser)]
+ #[grammar = "b.pest"]
+ pub struct ParserB;
+}
+```
+
## Other features
* Precedence climbing
## Projects using pest
* [pest_meta](https://github.com/pest-parser/pest/blob/master/meta/src/grammar.pest) (bootstrapped)
+* [AshPaper](https://github.com/shnewto/ashpaper)
* [brain](https://github.com/brain-lang/brain)
-* [Chelone](https://github.com/Aaronepower/chelone)
+* [cicada](https://github.com/mitnk/cicada)
* [comrak](https://github.com/kivikakk/comrak)
+* [elastic-rs](https://github.com/cch123/elastic-rs)
* [graphql-parser](https://github.com/Keats/graphql-parser)
* [handlebars-rust](https://github.com/sunng87/handlebars-rust)
* [hexdino](https://github.com/Luz/hexdino)
* [Huia](https://gitlab.com/jimsy/huia/)
+* [insta](https://github.com/mitsuhiko/insta)
+* [jql](https://github.com/yamafaktory/jql)
* [json5-rs](https://github.com/callum-oakley/json5-rs)
* [mt940](https://github.com/svenstaro/mt940-rs)
+* [Myoxine](https://github.com/d3bate/myoxine)
* [py_literal](https://github.com/jturner314/py_literal)
* [rouler](https://github.com/jarcane/rouler)
* [RuSh](https://github.com/lwandrebeck/RuSh)
* [tera](https://github.com/Keats/tera)
* [ui_gen](https://github.com/emoon/ui_gen)
* [ukhasnet-parser](https://github.com/adamgreig/ukhasnet-parser)
+* [ZoKrates](https://github.com/ZoKrates/ZoKrates)
+* [Vector](https://github.com/timberio/vector)
+* [AutoCorrect](https://github.com/huacnlee/autocorrect)
+* [yaml-peg](https://github.com/aofdev/yaml-peg)
+* [qubit](https://github.com/abhimanyu003/qubit)
+* [caith](https://github.com/Geobert/caith) (a dice roller crate)
+* [Melody](https://github.com/yoav-lavi/melody)
+
+## Minimum Supported Rust Version (MSRV)
+
+This library should always compile with default features on **Rust 1.56.1**
+or **Rust 1.61** with `const_prec_climber`.
## Special thanks
projects / rustc.git / blobdiff