ast-grep

Structure-aware code search uses AST patterns and metavariables to match code syntax precisely. You translate natural language queries into ast-grep rules, enabling structural matches across language trees rather than relying on flat text matching.

Ast-grep rules are YAML syntax configurations that define structural code search patterns using metavariables. Metavariables act as wildcards within AST patterns, allowing you to capture and match variable code elements within a defined syntactic structure.

To translate natural language queries into ast-grep rules, describe the code pattern you want to match. The tool drafts a YAML rule satisfying the syntax, then provides testing steps to validate the pattern against real code snippets in a repository.

You test structural code search rules by creating sample test files and applying the ast-grep rule to a real codebase. The workflow involves drafting a rule, testing it against code snippets, and iteratively refining the YAML pattern for precise matches.

Ast-grep performs static analysis by applying structure-aware rules across language trees. By leveraging AST patterns, it validates code structures and enforces rules regardless of specific text formatting variations in the codebase.

The best way to validate AST patterns is by creating simple sample test files with expected code snippets. You draft an ast-grep rule, test it against these snippets, and iteratively refine the YAML syntax before applying it to the full repository.