Open-source alternatives to Ast Types

This project is a technical handbook and tutorial guide for the Babel compiler. It serves as a resource for configuring the tool and writing custom plugins to transform JavaScript source code. The guide provides instructional material on creating custom transformation plugins and modifying the compilation process. It specifically covers how to navigate and modify abstract syntax trees to programmatically rewrite source code. The documentation covers the mechanics of code transformation, the management of compiler configurations, and the fundamentals of compiler tooling. It includes guidance

Hy is a Lisp implementation for Python that allows for writing Lisp syntax which compiles to Python bytecode. It operates as a Python-based Lisp dialect and S-expression language, providing full access to the Python standard library and ecosystem. The language focuses on macro-based metaprogramming, featuring an AST-walking macro system and reader macros that allow for custom syntax transformations and parsing rules. It enables the manipulation of the abstract syntax tree to extend language capabilities. The project includes a read-eval-print loop for interactive development and supports sta

ts-morph is a TypeScript AST manipulation library and a high-level wrapper for the TypeScript compiler API. It provides a programmatic interface for analyzing, modifying, and generating TypeScript source code, serving as a tool for automated code refactoring and source code generation. The library simplifies the process of navigating and inspecting project structures by offering an object-oriented abstraction over the underlying compiler API. It allows for the programmatic transformation of existing codebases to automate structural updates and bulk code migrations. Its capabilities cover sta

syn is a Rust syntax tree parser and token stream converter. It serves as a toolkit for procedural macro development, providing a framework to parse Rust source code into structured syntax trees for analysis and transformation. The project enables the manipulation of Rust abstract syntax trees through specialized visitor and folder patterns for traversing and mutating nodes. It provides a bidirectional mapping that allows developers to convert token streams into structured trees and print those trees back into tokens for code generation. The library covers a broad range of syntax analysis ca

ANTLR is a grammar-based code generator and multi-language parser generator used to design and implement custom languages. It functions as a toolkit for transforming formal language definitions into executable source code for processing structured text or binary files, while providing a framework for automatically constructing and traversing hierarchical parse trees. The project is distinguished by its ability to generate lexers and parsers in various target programming languages from a single shared grammar definition. It supports grammars containing direct left recursion and utilizes adapti

This is a collection of official extensions for the Rollup bundling process. These plugins serve as module transformers, resolution managers, and bundle optimizers designed to modify how JavaScript modules are processed, resolved, and optimized. The suite provides specialized capabilities for modern web transpilation, converting TypeScript, JSX, Flow, and GraphQL into compatible JavaScript. It distinguishes itself through extensive non-JavaScript asset integration, allowing the import of JSON, YAML, CSV, and image files as JavaScript modules or data URIs, and providing support for bundling We

JSqlParser is a Java library for SQL query parsing, converting raw SQL strings into a structured hierarchy of strongly typed Java objects. It provides the means to programmatically analyze and manipulate database queries by representing them as a tree of objects. The library supports both the parsing of existing SQL text and the programmatic generation of new statements through a fluent API. It includes mechanisms for transforming query trees and serializing structured object models back into formatted SQL text. Additional capabilities include database schema analysis, such as the extraction

Nearley is a JavaScript parser toolkit and context-free grammar compiler. It functions as an Earley parser generator that transforms BNF-like grammar definitions into executable code capable of analyzing text and generating abstract syntax trees. The project is distinguished by its ability to handle any context-free grammar, including those with left recursion and ambiguity, by maintaining multiple valid derivations for a single input. It further supports incremental parsing, allowing input strings to be processed in chunks to provide partial results and real-time feedback. Beyond core parsi

Tree-sitter is a parsing system and incremental parsing framework designed to generate high-performance syntax trees from source code. It functions as a language parsing engine that compiles formal grammar definitions into portable code, which can then be integrated into text editors and development tools to facilitate structural analysis, code navigation, and syntax highlighting. The project distinguishes itself through its ability to maintain valid, usable syntax tree structures even when source code contains syntax errors or incomplete fragments. It utilizes a generalized parsing algorithm

Markdig is a high-performance Markdown processor for .NET applications that converts Markdown text into HTML or other target formats. It is a CommonMark compliant parser and extensible engine that can transform Markdown into a searchable and manipulatable abstract syntax tree. The library provides a framework for adding custom syntax and rendering logic through a modular pipeline of parsers and renderers. It supports native ahead-of-time compilation and trimming to minimize binary size. Capabilities include the generation of structured HTML with custom attributes and styling, the extraction

Markdig is a markdown parser library that converts text into structured HTML, plain text, or other formats using a configurable pipeline. It functions as a CommonMark compliant parser and an abstract syntax tree generator that transforms markdown into a hierarchical tree of block and inline nodes with precise source location mapping. The project is distinguished by a decoupled renderer architecture that separates parsing logic from output generation, enabling the transformation of the syntax tree into non-HTML formats such as LaTeX or XAML. It also serves as a lossless markdown processor by t

fuckitpy is a Python exception suppression tool and AST modifier designed to ensure program execution continues despite the presence of runtime errors. It functions as a fault-tolerant module loader and error handling wrapper that rewrites Python code to skip statements that would otherwise cause crashes. The project utilizes abstract syntax tree manipulation to automatically inject exception handlers around expressions and functions. This allows for the loading of modules that contain errors, ensuring that valid members remain accessible even when the module itself is partially broken. The

HCL is a configuration language implementation designed for parsing, evaluating, and encoding structured settings through the use of blocks and attributes. It functions as a configuration AST parser and a schema-based decoder that maps attributes and blocks to internal data structures using predefined rules. The project includes an expression evaluation engine that resolves dynamic values and cross-references through multi-phase processing of variables and functions. It also provides a configuration file formatter to standardize the layout and indentation of source code for consistent visual

Terser is a JavaScript minifier and compressor designed to reduce file size through whitespace removal, symbol mangling, and logic optimization for ES6+. It functions as a toolkit for minification, a code mangler for shortening variable and property names, and a dead code eliminator that evaluates constant expressions to remove unreachable logic. The project operates as an AST toolkit that parses JavaScript source into SpiderMonkey AST format for structural analysis. It generates source maps to link compressed production code back to the original source, ensuring that minified bundles remain

Traceur is a JavaScript syntax transpiler that transforms modern and next-generation language features into compatible versions for older runtime environments. It functions as a compiler that translates proposed language standards and upcoming syntax into current versions to maintain cross-engine compatibility. The project operates as an asynchronous code transformer, converting async functions and generators into promise-based state machines. It includes a functional tail-call optimizer that wraps recursive functions in trampolines to prevent stack overflows and an ECMAScript polyfill engine

This project is a comprehensive manual and educational resource focused on the Babel compiler. It serves as a documentation guide and handbook for understanding the inner workings of JavaScript compilation, specifically regarding the transformation of source code. The material provides a technical walkthrough for developing custom plugins and extensions. It covers the process of creating tailored transformations to modify how JavaScript is parsed and generated. The content encompasses the broader JavaScript compilation workflow, focusing on abstract syntax tree manipulation, code generation,

SpotBugs is a static analysis tool and bytecode analyzer for Java applications. It scans compiled class files to identify bugs, security vulnerabilities, and performance issues without executing the code. The system functions as both a bug detector and a static application security testing tool to locate logical errors and API misuse. The project distinguishes itself through a plugin-based detector architecture that allows the integration of external libraries to add custom detection rules. It provides specialized security auditing for vulnerabilities such as SQL injection, cross-site scripti

Lebab is a JavaScript code modernization tool that converts older ES5 syntax into contemporary ES6 equivalents. It operates as a source-to-source transpiler, parsing code into an abstract syntax tree, applying structural transformations, and regenerating the output without intermediate representations or runtime dependencies. The tool distinguishes itself through a rule-driven pipeline of independent transformation rules, each targeting a specific ES6 feature like arrow functions, let/const, classes, or modules. It provides a programmatic API that accepts source code and an array of transform

PMD is a multi-language static code analyzer used to identify programming flaws, unused variables, and dead code without executing the program. It functions as a code smell detector and coding standard enforcer, ensuring source code adheres to specific naming conventions, structural requirements, and project style guides. The project features an XPath-based rule engine that allows users to define custom analysis patterns using queries against an abstract syntax tree. It also includes a copy-paste detector to identify duplicated code blocks across multiple files and a visual rule designer for

GoGoCode is an AST-based code transformation toolkit that enables developers to query, match, and rewrite JavaScript source code using jQuery-style selectors and wildcard patterns. At its core, it provides a programmatic code refactoring library that manipulates parsed AST nodes, allowing precise structural modifications without worrying about formatting differences. The toolkit also functions as a JavaScript AST query engine, finding code patterns through snippet-based matching with wildcards that capture unknown or variable-length fragments. What distinguishes GoGoCode is its callback-drive

Istanbul is a JavaScript code coverage tool and instrumentation engine that measures the execution of statements, lines, functions, and branches. It functions as a test coverage analysis tool capable of monitoring code across unit, functional, and browser tests to identify untested areas of a codebase. The project distinguishes itself through a transparent instrumentation engine that uses module loader hooks to inject tracking code without requiring manual source modifications. It supports distributed test reporting by aggregating fragmented coverage data from multiple concurrent processes in

This project is a JavaScript code protection tool designed to transform source code into a version that is difficult for humans to read. Its primary purpose is to protect intellectual property and prevent reverse engineering by altering the original program logic. The tool employs several advanced techniques to hinder analysis, including control flow flattening and the injection of dead code. It can compile functions into custom bytecode executed by an embedded virtual machine and encrypt string literals to prevent static analysis of text. Additional capabilities include anti-debugging mecha

OpenRewrite is an automated refactoring engine and source-to-source migration framework. It uses a lossless semantic tree parser to represent source code as type-aware trees that preserve original whitespace and formatting, enabling precise and deterministic modifications. The project utilizes a declarative refactoring pipeline where sequences of transformations are defined in YAML to resolve breaking changes and technical debt. It features type-aware pattern matching and cross-language model mapping to apply similar refactoring patterns across different programming languages. The framework

JavaParser is a library that parses Java source code up to version 12 into an Abstract Syntax Tree (AST), enabling programmatic analysis, transformation, and generation of Java code. It serves as a parser, code analyzer, code generator, comment parser, and symbol resolver, providing a unified toolkit for working with Java source at the AST level. The library distinguishes itself through several integrated capabilities that go beyond basic parsing. It includes a symbol resolution engine that resolves type and symbol references across files for accurate semantic analysis, and an error-recovery

This project is an ESLint plugin and static analysis tool designed to enforce best practices, prevent bugs, and maintain code quality in React projects. It functions as a specialized JSX linter that analyzes the syntax and structure of components to detect anti-patterns and API misuse. The plugin distinguishes itself by providing deep analysis of React-specific patterns, such as detecting state race conditions, preventing nested component definitions, and identifying unstable references that cause unnecessary re-renders. It also includes security hardening rules to identify vulnerabilities li

Tern is an editor-independent code analyzer and static analysis engine for JavaScript. It functions as a language server that provides semantic intelligence by parsing source code into abstract syntax trees to infer types and resolve symbols without requiring manual type annotations. The engine distinguishes itself through the use of JSON-based type definitions, which allow it to describe library signatures and external dependencies without needing the original source code. It also features a plugin system that enables the extension of server functionality to support custom loaders or framewo

Lightning CSS is a high-performance CSS toolchain implemented in Rust. It provides a comprehensive suite of tools for stylesheet processing, including a bundler, minifier, module compiler, syntax lowerer, and vendor prefixer. The engine utilizes a browser-grade grammar for parsing and converts stylesheets into typed property values. It distinguishes itself through a visitor-based transformation API that allows for custom modifications of the parsed abstract syntax tree and an error-tolerant parsing mechanism that recovers from malformed syntax to prevent build failures. The toolset covers br