pest-parser/pest
Pest
Pest is a Rust parsing library and automatic parser generator that transforms formal grammar definitions into functional parsers. It specializes in Parsing Expression Grammar to recognize and structure complex text patterns, providing a system for context-free grammar parsing.
The library implements zero-copy tokenization and static grammar compilation to reduce runtime overhead. It supports no-std runtime compatibility, allowing the parser to be compiled for embedded or bare-metal environments where a standard library is unavailable.
The project covers a range of parsing capabilities, including the extraction of nested token pairs and automated syntax validation. It is used for implementing domain-specific languages, custom language parsing, and mathematical expression evaluation. It also provides automated error reporting to identify unexpected tokens or missing input.
Features
- PEG Grammar Parsers - Implements a Parsing Expression Grammar (PEG) engine to ensure unambiguous derivation of input text.
- Custom Text Format Parsing - Enables the definition of grammar rules to transform raw text into structured data for custom formats.
- Domain Specific Languages - Facilitates the implementation of custom languages with specific rules and syntax for application domains.
- No-Standard-Library Modes - Supports operation in environments without a standard library by omitting system-level dependencies.
- Rust Parsing Libraries - Provides a comprehensive Rust library for building language parsers with no-std support.
- Formal Grammar Parser Generators - Automatically generates a functional parser implementation and error reporting from a defined formal grammar.
- Grammar-Based Parsers - Recognizes and structures complex text patterns using declarative context-free grammar files.
- Recursive Descent Parsers - Utilizes recursive descent execution to match input patterns against the defined grammar hierarchy.
- Parse Tree Extractions - Provides a hierarchical tree of rule names and byte offsets for efficient traversal of parsed input.
- Syntax Validation - Checks input text against a formal grammar to identify syntax violations and report unexpected tokens.
- Zero-Copy Parsing - Processes input streams using pointers to original text slices to eliminate unnecessary memory allocations.
- Grammar Compilation - Transforms formal grammar definitions into optimized internal representations during the build process.
- General Purpose Embedded Parsing - Implements text parsing in restricted hardware environments by compiling without the standard library.
- Embedded System Compilations - Allows the parser to be compiled for embedded or bare-metal environments where a standard library is unavailable.
- Parse Error Reporters - Generates automatic error messages based on grammar definitions to identify unexpected tokens or missing input.
- Parser Generators - PEG parser generator for Rust.
