AST-Grep Code Search

Use ast_grep_search and ast_grep_replace for semantic code search/replace. ast-grep understands code structure, not just text.

These tools (plus ast_grep_outline, lsp_navigation) are registered but inactive by default on hosts that support pi's dynamic tooling. If a call to one of them isn't recognized, activate it first: pi_lens_activate_tools tools=["ast_grep_search", "ast_grep_replace"].

On hosts that aggregate pi-lens behind a single lens tool, the ast_grep_* tools and pi_lens_activate_tools may not be registered at all. There, fall back to the ast-grep CLI (alias sg) — patterns, metavariables, and YAML rules are identical:

# search (≈ ast_grep_search)
ast-grep run -p 'fetchMetrics($$$ARGS)' -l ts src/

# rewrite (≈ ast_grep_replace; -U applies all)
ast-grep run -p 'var $X' -r 'let $X' -l js src/ -U

# full YAML rule (≈ the rule: parameter)
ast-grep scan --rule my-rule.yml src/