Grep source code files and see matching lines with useful context that
show how they fit into the code. See the loops, functions, methods,
classes, etc that contain all the matching lines. Get a sense of what's
inside a matched class or function definition. You see relevant code from
every layer of the abstract syntax tree, above and below the matches.

By default, grep-AST recurses the current directory to search all source
code files. It respects .gitignore, so it will usually "do the right
thing" in most repos if you just do grep-ast <regex> without specifying
any filenames.

You can also invoke grep-ast as gast for convenience.