0xDarkMatter

structural-search

"Search code by AST structure using ast-grep. Find semantic patterns like function calls, imports, class definitions instead of text patterns. Triggers on: find all calls to X, search for pattern, refactor usages, find where function is used, structural search, ast-grep, sg."

0xDarkMatter 20 2 Updated 5mo ago

Resources

3
GitHub

Install

npx skillscat add 0xdarkmatter/claude-mods/structural-search

Install via the SkillsCat registry.

SKILL.md

Structural Search

Search code by its abstract syntax tree (AST) structure. Finds semantic patterns that regex cannot match reliably.

Tools

Tool Command Use For
ast-grep sg -p 'pattern' AST-aware code search

Pattern Syntax

Pattern Matches Example
$NAME Named identifier function $NAME() {}
$_ Any single node console.log($_)
$$$ Zero or more nodes function $_($$$) {}

Top 10 Essential Patterns

# 1. Find console.log calls
sg -p 'console.log($_)'

# 2. Find React hooks
sg -p 'const [$_, $_] = useState($_)'
sg -p 'useEffect($_, [$$$])'

# 3. Find function definitions
sg -p 'function $NAME($$$) { $$$ }'
sg -p 'def $NAME($$$): $$$' --lang python

# 4. Find imports
sg -p 'import $_ from "$_"'
sg -p 'from $_ import $_' --lang python

# 5. Find async patterns
sg -p 'await $_'
sg -p 'async function $NAME($$$) { $$$ }'

# 6. Find error handling
sg -p 'try { $$$ } catch ($_) { $$$ }'
sg -p 'if err != nil { $$$ }' --lang go

# 7. Find potential issues
sg -p '$_ == $_'           # == instead of ===
sg -p 'eval($_)'           # Security risk
sg -p '$_.innerHTML = $_'  # XSS vector

# 8. Preview refactoring
sg -p 'console.log($_)' -r 'logger.info($_)'

# 9. Apply refactoring
sg -p 'var $NAME = $_' -r 'const $NAME = $_' --rewrite

# 10. Search specific language
sg -p 'pattern' --lang typescript

Quick Reference

Task Command
Find pattern sg -p 'pattern'
Specific language sg -p 'pattern' --lang python
Replace (preview) sg -p 'old' -r 'new'
Replace (apply) sg -p 'old' -r 'new' --rewrite
Show context sg -p 'pattern' -A 3
JSON output sg -p 'pattern' --json
File list only sg -p 'pattern' -l
Count matches sg -p 'pattern' --count
Run YAML rules sg scan

When to Use

  • Finding all usages of a function/method
  • Locating specific code patterns (hooks, API calls)
  • Preparing for large-scale refactoring
  • When regex would match false positives
  • Detecting anti-patterns and security issues
  • Creating custom linting rules

Additional Resources

For complete patterns, load:

  • ./references/js-ts-patterns.md - JavaScript/TypeScript patterns
  • ./references/python-patterns.md - Python patterns
  • ./references/go-rust-patterns.md - Go and Rust patterns
  • ./references/security-patterns.md - Security vulnerability detection
  • ./references/advanced-usage.md - YAML rules and tool integration
  • ./assets/rule-template.yaml - Starter template for custom rules