ast-grep vs jSparrow

ast-grep is a free, open-source tool for structural code search, linting, and rewriting. It matches patterns against syntax-tree nodes, helping developers locate and change code across a codebase rather than searching plain text. Its CLI can preview and apply rewrites interactively, and scan configurable YAML rules with error, warning, info, or hint severity. Rules can combine pattern, kind, regex, relational, and composite conditions, and CLI commands help create and snapshot-test them. The project says it supports more than 20 languages and can load custom languages. JavaScript and WebAssembly APIs allow programmatic syntax-tree work; a browser playground offers a way to try patterns without local installation. Editor options include a VS Code extension and language-server setups, including for Vim and Neovim. The tool is free, has a web interface, and is distributed through package managers or built from source. Its FAQ notes that some advanced static-analysis information is unsupported, and one rule cannot target multiple languages at once.

jSparrow is a Java cleanup and refactoring tool for Eclipse IDE and Maven, running on Linux, macOS and Windows. It lists more than 90 refactorings for Java 1.1 and later, with project-level and batch operation. Diff View compares original and proposed code so changes can be reviewed before application. Markers suggest quick fixes during programming, and the base product includes them at no charge. Interactive rules can replace standard output with logging, rename fields to Java naming conventions and remove unused methods, fields and types. Analysis and refactoring run offline, and the FAQ says code is not sent to external servers or third parties. Internet access is required to persist locked refactorings through the NetLicensing API; offline validation servers are available. The site describes jSparrow as open-source, with no license needed since version 4.20.0. Twenty rules are free; paid licenses are $169 a month or $1,325 a year.