New upstream version 1.68.2+dfsg1

[rustc.git] / vendor / pest_derive / _README.md

diff --git a/vendor/pest_derive/_README.md b/vendor/pest_derive/_README.md
index f91188ccbebf831a2dd5b25f8664c3a521ae1455..da30ab74ebc0fc21bb444b15e3dd03d859a0e962 100644 (file)
--- a/vendor/pest_derive/_README.md
+++ b/vendor/pest_derive/_README.md
@@ -5,8 +5,8 @@
 
 # pest. The Elegant Parser
 
-[![Join the chat at https://gitter.im/dragostis/pest](https://badges.gitter.im/dragostis/pest.svg)](https://gitter.im/dragostis/pest?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Book](https://img.shields.io/badge/book-WIP-4d76ae.svg)](https://pest-parser.github.io/book)
+[![Join the chat at https://gitter.im/pest-parser/pest](https://badges.gitter.im/dragostis/pest.svg)](https://gitter.im/pest-parser/pest?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Book](https://img.shields.io/badge/book-WIP-4d76ae.svg)](https://pest.rs/book)
 [![Docs](https://docs.rs/pest/badge.svg)](https://docs.rs/pest)
 
 [![pest Continuous Integration](https://github.com/pest-parser/pest/actions/workflows/ci.yml/badge.svg)](https://github.com/pest-parser/pest/actions/workflows/ci.yml)
@@ -31,25 +31,28 @@ Other helpful resources:
 
 * 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 alphanumeric identifiers
-where the first identifier does not start with a digit:
+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
 ```
@@ -81,6 +84,9 @@ thread 'main' panicked at ' --> 1:1
   = 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.
@@ -133,6 +139,25 @@ Letter:  b
 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