Open-source alternatives to Dtolnay Syn

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

swift-syntax is a library for parsing, manipulating, and generating Swift source code. It provides a source-accurate abstract syntax tree representation of Swift code, acting as a parser, transformer, and code generator. The project serves as the infrastructure for Swift macro development, enabling the expansion and transformation of source code during compilation. It is used to build compiler tooling for static analysis, formatting, and automated refactoring. The system covers a broad range of source analysis capabilities, including the ability to convert source code into structured trees f

Nearley is a JavaScript parser toolkit used to define context-free grammars and generate corresponding parsers. It features an EBNF grammar compiler that transforms language definitions written in extended Backus-Naur Form into executable JavaScript code, utilizing an Earley parser implementation to process any context-free grammar. The toolkit distinguishes itself by its ability to handle left-recursion and ambiguity without failing, allowing it to identify and return multiple valid derivations for a single input string. It also includes a grammar fuzzing generator to produce random strings

Semantic is a Haskell-based library and command-line tool designed for polyglot source code analysis. It functions as a static program analysis framework and a polyglot abstract syntax tree parser that converts multiple programming languages into structured syntax trees based on grammar definitions. The system distinguishes itself through a semantic code comparison engine that detects structural and meaningful changes between code versions rather than relying on textual differences. It further enables analysis across different programming syntaxes by translating surface languages into a unifi

Scriban is a .NET text templating engine and embedded scripting language used for dynamic text generation. It functions as an abstract syntax tree manipulation tool and a template parser, allowing for the conversion of scripts into visitable trees for analysis, modification, and rendering. The engine is specifically designed for Native AOT compatibility, utilizing a reflection-free API to execute templates in trimmed environments. It also provides a dedicated parser and conversion system for Liquid templates, enabling the migration and execution of Liquid scripts within .NET. The project cov

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

This project is a formal markdown specification standard that provides a detailed markup syntax definition and a definitive set of rules for parsing plain text into consistent HTML output. It establishes a standardized grammar for structural blocks and inline elements to ensure uniform rendering across different software implementations. The specification is supported by a parser conformance suite and a reference implementation in C and JavaScript to verify that implementations adhere to the standard. It includes a system for implementation verification that compares transformed input strings

Emmet is a markup code generator and web development productivity toolkit. It serves as an expansion engine that converts shorthand abbreviations and CSS-like selectors into full HTML, XML, and other markup structures. The project features a dedicated CSS shorthand expansion engine that transforms concise property codes into full style declarations, including the automatic generation of vendor prefixes and gradients. It distinguishes itself by offering a programmable expansion process through custom snippet definitions, abbreviation alias mapping, and script-based extensibility. The toolkit

CodeMirror is a browser-based code editor framework and modular extension system used to embed full-featured text editors into web pages. It functions as a syntax tree parsing engine and a language server protocol client, enabling structural language analysis and deep integration with external programming language services. The project is distinguished by its modular architecture, which uses a system of extensions and compartments for dynamic reconfiguration at runtime. It supports real-time collaborative editing and state synchronization through an operational transformation framework, allow

JSHint is a JavaScript static analysis tool and linter designed to detect errors and enforce coding standards. It functions as a syntax validator that scans source code to identify potential logic problems and programming mistakes before the code is executed. The tool provides a command line interface for analyzing files and directories. It supports the export of analysis results into standardized formats such as Checkstyle for integration with external build tools. Analysis is managed through a system of linting rule management and environment global configuration. This includes the ability

Recast is a JavaScript AST parser and printer designed for automated code refactoring. It converts source code into abstract syntax trees that can be modified and then printed back into source code. The project focuses on formatting-preserving transformations, storing original whitespace and indentation metadata within syntax tree nodes to reconstruct code without losing its original layout. It also generates character-level source maps to maintain precise correspondences between original input and transformed output. The toolkit includes utilities for syntax tree manipulation using a visito

Commonmark.js is a library designed to parse and render text formatted according to the CommonMark specification. It functions as a document processing pipeline that converts plain text into structured HTML or an abstract syntax tree, enabling developers to programmatically inspect, modify, and transform document elements. The library distinguishes itself through its strict adherence to standardized parsing rules, ensuring consistent and predictable output across different software environments. It provides a robust framework for document tree manipulation, allowing users to traverse, insert,

Esprima is a JavaScript parser that converts source code into a structured abstract syntax tree. It implements a specification-driven grammar to ensure compliance with ECMAScript standards, enabling the programmatic analysis and transformation of JavaScript programs. The project provides capabilities for lexical tokenization to break source code into individual symbols and static syntax validation to verify that scripts are well-formed without executing the code. Its functional surface covers JavaScript static analysis, lexical analysis, and the generation of abstract syntax trees.

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

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

Goldmark is a Markdown parser and renderer written in Go that converts Markdown text into HTML or XHTML. It implements the CommonMark specification to ensure consistent parsing behavior. The project utilizes a modular extension registry, allowing for the addition of custom syntax such as tables, task lists, and footnotes. It also includes specialized support for CJK languages to handle specific line-breaking and emphasis rules for Chinese, Japanese, and Korean characters. The library parses text into an abstract syntax tree for programmatic document analysis and modification. Its capabilitie

Oclint is a static analysis engine and extensible linting framework designed for C, C++, and Objective-C source code. It functions as a code quality tool that identifies bugs, code smells, and structural complexities by parsing source code into abstract syntax trees to perform semantic inspection. The project is distinguished by its modular architecture, which supports dynamic plugin loading for custom inspection rules and a pluggable reporter system for exporting analysis findings in multiple formats. It replicates build configurations by reading compiler flags and include paths to ensure th

markdown-js is a JavaScript markdown parser and converter that transforms markdown text into HTML output. It functions as both a library and a command line interface tool for converting documents. The project is centered on an abstract syntax tree representation, allowing markdown to be parsed into a structured tree for programmatic inspection and modification before the final rendering process. This intermediate representation enables custom markup processing and document transformations. The toolset covers programmatic document parsing, static site generation, and CLI-based file processing

Lark is a Python parsing toolkit used to define grammars and convert raw text into annotated parse trees. It serves as an abstract syntax tree generator and a grammar definition language for specifying language rules through terminals and regular expressions. The library provides two primary parsing implementations: an Earley parsing library capable of handling all context-free languages, including those with ambiguity and left-recursion, and a high-performance LALR parsing library designed for deterministic languages with low memory overhead. Beyond core parsing, the toolkit includes capabi

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

This project is a framework for building, manipulating, and analyzing abstract syntax trees. It provides a toolkit for defining, traversing, and validating syntax trees that are compatible with the Mozilla Parser API, serving as a foundation for static code inspection and automated transformation tasks. The library distinguishes itself through a declarative type system that enforces structural integrity across node hierarchies. By wrapping raw syntax nodes in context-aware objects, it enables developers to track parent relationships and ancestor chains without modifying the underlying tree st

phpDocumentor is a PHP API documentation generator and source code analyzer that transforms PHP files and DocBlocks into structured HTML API references. It functions as a static site generator and an automatic documentation tool designed to synchronize technical documentation with code changes. The project distinguishes itself by acting as a UML diagram generator, producing class and architectural graphs via PlantUML based on source analysis. It also supports technical manual authoring, rendering hand-written guides in Markdown and ReStructuredText alongside the automatically generated API re

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,

Prost is a Protocol Buffers implementation for Rust that functions as a binary serialization framework and code generator. It translates schema definitions into idiomatic Rust structs and enums, providing the logic necessary to encode and decode structured data into the Protocol Buffers binary format. The project distinguishes itself through a no-std implementation, allowing it to operate in embedded or kernel environments that lack a standard library. It also serves as a schema introspector by emitting file descriptor sets, which enables the programmatic analysis of original schema definitio

This project is a unified toolchain for JavaScript and TypeScript development, providing a suite of specialized tools for bundling, parsing, linting, and formatting source code. The toolchain is implemented in Rust and utilizes a shared internal representation to allow multiple tools to operate on the same parsed source code. It employs a parallelized analysis pipeline and single-pass parsing with error recovery to process files across CPU cores. The suite covers several core capability areas, including static analysis for identifying programmatic errors, automated style standardization, and

sqlglot is a SQL parser and transpiler that represents queries as abstract syntax trees to enable structural analysis, modification, and semantic transformation. It functions as a dialect translator and query optimizer, converting SQL code between different database engines and simplifying syntax trees through rule-based normalization. The project provides a framework for defining custom SQL dialects by overriding tokenizers, parsers, and generators. It includes a lineage analyzer to track data flow from source tables through complex queries to identify the origin of specific columns. Additi

Boa is a high-performance JavaScript engine and parser designed to execute JavaScript code and analyze source code structure. It functions as a runtime environment for executing scripts to automate tasks or process data, providing both a command-line JavaScript interpreter and a tool for converting source code into abstract syntax trees. The engine is capable of compiling to WebAssembly, allowing the runtime to be deployed and executed within web browser environments. It includes an interactive read-eval-print loop for real-time logic testing and snippet execution via a terminal. The system