https://github.com/chaosunity/ebnf

A successor bnf parsing library of bnf parsing library, for parsing Extended Backus–Naur form context-free grammars
https://github.com/chaosunity/ebnf

ebnf ebnf-syntax parser rust

Last synced: 4 months ago
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A successor bnf parsing library of bnf parsing library, for parsing Extended Backus–Naur form context-free grammars

• Host: GitHub
• URL: https://github.com/chaosunity/ebnf
• Owner: ChAoSUnItY
• License: mit
• Created: 2022-03-17T18:38:20.000Z (almost 4 years ago)
• Default Branch: main
• Last Pushed: 2025-09-17T18:04:53.000Z (4 months ago)
• Last Synced: 2025-09-20T09:12:18.020Z (4 months ago)
• Topics: ebnf, ebnf-syntax, parser, rust
• Language: Rust
• Homepage:
• Size: 29.3 KB
• Stars: 14
• Watchers: 1
• Forks: 4
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# ebnf

[![Crates.io](https://img.shields.io/crates/v/ebnf)](https://crates.io/crates/ebnf)

[![Docs](https://docs.rs/ebnf/badge.svg)](https://docs.rs/ebnf/)

[![.github/workflows/push.yml](https://github.com/ChAoSUnItY/ebnf/actions/workflows/push.yml/badge.svg)](https://github.com/ChAoSUnItY/ebnf/actions/workflows/push.yml)

> A successor bnf parsing library of bnf parsing library, for parsing Extended Backus–Naur form context-free grammars

The code is available on [GitHub](https://github.com/ChAoSUnItY/ebnf)

## Disclaimer:

There are various variants of EBNF, which uses somewhat different syntactic conventions. This library 

takes [EBNF Evaluator](https://mdkrajnak.github.io/ebnftest/)'s example code as standard, which has 

almost most syntactic conventions on Wikipedia's page.

## What does a valid EBNF grammar looks like?

The following example is taken from EBNF Evaluator:

```ebnf

filter ::= ( first ' ' )? ( number '~ ' )? ( number '-' number ) ( ' ' number '~' )? ( ' hz' )? ( ' b' )? ( ' i' )? ( ' a' )?;

first  ::= #'[a-za-z][a-za-z0-9_+]*';

number ::= digits ( ( '.' | ',' ) digits? )?;

digits ::= #'[0-9]+';

```

## How to use this library?

```rust

extern crate ebnf;

fn main() {

    let source = r"

        filter ::= ( first ' ' )? ( number '~ ' )? ( number '-' number ) ( ' ' number '~' )? ( ' hz' )? ( ' b' )? ( ' i' )? ( ' a' )?;

        first  ::= #'[a-za-z][a-za-z0-9_+]*';

        number ::= digits ( ( '.' | ',' ) digits? )?;

        digits ::= #'[0-9]+';

    ";

    let result = ebnf::get_grammar(source);

}

```