bnf_rules

Crates.iobnf_rules
lib.rsbnf_rules
version0.1.7
created_at2023-11-26 14:30:05.965203+00
updated_at2025-06-14 09:48:28.77897+00
descriptionLR(1) parser generator
homepage
repositoryhttps://github.com/bea4dev/bnf_rules
max_upload_size
id1049151
size24,052
bea4dev (bea4dev)

documentation

README

bnf_rules!

LR(1) parser generator

Generate LR(1) parser at compilation time.

use bnf_rules::bnf_rules_macro::bnf_rules;

// Grammar
bnf_rules!(
    source   ::= expr
    expr     ::= factor { "+" factor }
    factor   ::= "-" primary | primary
    primary  ::= "(" expr ")" | number
    number   ::= r"\d+" // regex
);

pub fn parse() {

    // A function named "parse_source" is automatically generated.
    let ast_node: Result<ASTNode, ParseError> = parse_source("(100 + 200) + -100");
    dbg!(ast_node.unwrap());

}

Usage

bnf_rules = "0.1.7"

Extended BNF

Form Semantic
source An entire input source.
ident A non-terminal symbol named "ident".
"something" A terminal symbol for text.
r"\d+" A terminal symbol for regex.
fn (function_name) A custom tokenizer with user function.1
{ pattern } Zero or more repetitions of "pattern".
[ pattern ] "pattern" or null.
pattern1 | pattern2 "pattern1" or "pattern2".
( patterns ) A group of patterns.

Example 1: https://github.com/bea4dev/bnf_rules/blob/master/src/lib.rs

Example 2: https://github.com/bea4dev/catla/blob/master/catla_parser/src/grammar.rs

Footnotes

  1. Generic parameters are also available. ↩

Commit count: 48

cargo fmt