lark-parser/lark
Lark
Lark 是一个 Python 解析工具包，用于定义语法并将原始文本转换为带注释的解析树。它作为一个抽象语法树生成器和语法定义语言，用于通过终结符和正则表达式指定语言规则。
该库提供两种主要的解析实现：一种是能够处理所有上下文无关语言（包括具有歧义和左递归的语言）的 Earley 解析库；另一种是专为具有低内存开销的确定性语言设计的高性能 LALR 解析库。
除了核心解析外，该工具包还包括模块化语法组合、基于规则的树转换以及源位置坐标跟踪功能。它还支持将 LALR 语法序列化为独立的解析器模块。
Features
- Parsing Toolkits - Provides a comprehensive suite of parsing algorithms and grammar definition tools for transforming raw text into structured parse trees.
- AST Generators - Acts as a toolkit for transforming raw input text into hierarchical abstract syntax trees based on predefined grammars.
- Parsing and Grammars - Converts raw text into annotated parse trees based on user-defined grammar rules.
- Custom Language Definitions - Enables the definition of custom language structures using grammar rules and regular expressions.
- Grammar Rule Specification - Allows users to define the structure of a language using a high-level syntax for recursive rules and regular expressions.
- Context-Free Grammar Frameworks - Implements a framework capable of parsing all context-free languages, including those with ambiguity and left-recursion.
- Formal Grammar Specifications - Allows the definition of recursive rules and terminals using extended Backus-Naur Form (EBNF) syntax.
- Annotated Parse Trees - Transforms raw text into hierarchical parse trees annotated with grammar rule matches and source positions.
- Abstract Syntax Tree Parsing - Automatically generates a hierarchical tree representation of the input text based on the defined grammar.
- Concrete Parse Tree Generation - Automatically builds full, annotated hierarchical parse trees based on the specified grammar structure.
- AST Generators - Automatically generates hierarchical abstract syntax trees by matching input tokens against defined grammar rules.
- LALR Parsers - Implements a high-performance LALR parser using look-ahead left-to-right shift-reduce algorithms for deterministic languages.
- Earley Parser Implementations - Implements the Earley parsing algorithm to support all context-free languages, including those with left-recursion.
- Earley Parsers - Implements the Earley parsing algorithm to handle all context-free grammars, including those with ambiguity and left-recursion.
- Interactive Grammar Debugging - Offers tools to design and debug language grammars by inspecting parser decisions interactively.
- Ambiguity Management - Supports marking multiple valid interpretations of a single input string when using the Earley parsing algorithm.
- High-Performance Text Processing - Uses LALR algorithms to process large volumes of text with high efficiency and low memory usage.
- Grammar Compositions - Provides the ability to import terminals and rules from multiple external grammar files to build complex parsing logic.
- Domain Specific Language Parsers - Provides tools to build specialized parsers for custom data formats and complex recursive configuration languages.
- Parsing Optimizations - Implements high-performance LALR parsing to increase execution speed and reduce memory overhead.
- Source Coordinate Tracking - Provides line and column offset tracking for tokens to map parse tree nodes back to the original source code.
- Standalone Parser Generators - Compiles LALR grammars into self-contained parser modules to remove dependencies on the full toolkit.
- Coordinate Tracking - Tracks line and column numbers for every element in the parse tree to facilitate precise error reporting and debugging.
- Grammar Extensions - Imports terminals and rules from external libraries to reuse common language patterns within a grammar.
- Grammar Compositions - Supports importing and combining separate grammar definitions to build complex languages from reusable components.
- Syntax Tree Transformers - Uses a visitor-pattern mechanism to transform parse trees into custom data structures via specific grammar branch mappings.
