0.7.0

[kevinmehall]

New features

• Significantly improved compile-time error messages for invalid grammars
• Support [MyToken(x)] syntax for capturing variables from pattern expressions ( Add support for capturing variables from pattern expressions #245)
• Restore support for [^ ] inverted pattern syntax
• Add #[no_eof] pub rule() = ... syntax to allow matching a prefix of the input rather than reporting a parse error if the rule does not reach end-of-file (Allow nonexhaustive rules #233)
• Allow rule _ = without parentheses when defining special underscore rule (How do "_" rules work? #243)
• Add grammar-level type and lifetime parameters (Accept type parameters on grammar (e.g. lifetimes) (Fixes #220) #254)
• Compile-time check for repeat expressions that infinite-loop without consuming input (Repeat expression that doesn't consume input should be a compile time error #210)
• Implement PartialEq, PartialOrd, Eq, Ord, Debug, Hash for RuleResult (Derive more Implementations for RuleResult #217)

Fixes

• Extend detection of infinite-loop left recursion to check inside precedence!() (Compile-time recursion check doesn't work inside precedence macro #238)
• Wrap user-supplied code in immediately-invoked closure so that return and ? behave as expected (Control flow in {? } blocks #246)
• Remove overzealous error checks to allow passing rule closure arguments as parameters to another call (Reached the type-length limit on parser! macro invocation #226)

Breaking changes

• Add required is_eof() method to Parse trait (Add is_eof() function to Parse trait #252)
• Certain patterns that would infinite-loop or stack overflow if executed are now a compile-time error
• mixed_site hygiene prevents action code from accessing internal parser state variables such as __input, __pos, etc.

Contributors

@kevinmehall @dario23 @bgw @adrianwn

---

This discussion was created from the release 0.7.0.

[godmar]

My first attempt at using rust-peg has been an absolute breeze. With barely any knowledge of Rust everything fit together intuitively and beautifully. I used it to port an old shell grammar written in yacc. Well done.