tpeg

tpeg is a lightweight and flexible library for parsing text using Parsing Expression Grammars (PEGs) in TypeScript. It provides a set of combinators that allow you to define grammars in a declarative way, making it easy to parse complex text formats.

✨ Key Features

• 🚀 Lightweight: Minimal dependencies and a small footprint.
• 🧩 Declarative Grammars: Define grammars using composable combinators, resulting in clean, readable, and maintainable code.
• 🛠️ Flexible & Powerful: Supports a wide array of parsing operations, including sequence, choice, repetition, and lookahead predicates.
• 🛡️ TypeScript-First: Built from the ground up with TypeScript, providing robust type safety and an exceptional developer experience.

Usage

Core Combinators

tpeg provides a set of core combinators for building parsers:

• any(): Parses any single character.
• lit(str): Parses a literal string.
• charClass(...charsOrRanges): Parses a character within a specified set or range.
• seq(...parsers): Parses a sequence of parsers.
• choice(...parsers): Parses one of several alternative parsers.
• opt(parser): Parses an optional parser (zero or one occurrence).
• star(parser): Parses zero or more occurrences of a parser.
• plus(parser): Parses one or more occurrences of a parser.
• and(parser): Positive lookahead (checks if a parser succeeds without consuming input).
• not(parser): Negative lookahead (checks if a parser fails without consuming input).
• map(parser, f): Transforms the result of a parser using a mapping function.
• mapResult(parser, f): Transforms the result of a parser using a mapping function that receives the whole ParseSuccess object.

📚 Examples

Explore these examples to see tpeg in action:

• Simple Arithmetic Expression Parser: Parse and evaluate basic arithmetic expressions.
• PEG Grammar Parser: Parse PEG grammars themselves, demonstrating the power of tpeg.

🤝 Contributing

We welcome contributions from the community! If you're interested in helping improve tpeg, please:

• Open an issue to report bugs or suggest new features.
• Submit a pull request with your proposed changes.

📄 License

This project is licensed under the MIT License.