AST-based Code Editing

Edit code by finding functions by name, not text matching. Edits always succeed through AST analysis instead of fragile text replacements.

Sby Skills Guide Bot
DevelopmentIntermediate0 views0 installs3/3/2026
Claude CodeCursor
ast-parsingrefactoringcode-editingsymbol-navigationsafe-edits

name: syntax description: "Edits that never fail. Find functions by name, not text matching." allowed-tools: mcp__syntax__list_symbols, mcp__syntax__read_symbol, mcp__syntax__edit_symbol, mcp__syntax__edit_lines, mcp__syntax__get_imports, mcp__syntax__get_exports, mcp__syntax__add_import, mcp__syntax__remove_unused_imports, mcp__syntax__organize_imports, mcp__syntax__search_symbols, mcp__syntax__find_references, mcp__syntax__rename_symbol, mcp__syntax__get_callers, mcp__syntax__get_callees, mcp__syntax__analyze_deps, mcp__syntax__move_file, mcp__syntax__move_symbol, mcp__syntax__extract_function, mcp__syntax__inline_function, mcp__syntax__find_unused_exports, mcp__syntax__apply_edits, mcp__syntax__batch_edit_symbols, mcp__syntax__trace, mcp__syntax__find_paths, mcp__syntax__find_dead_code

syntax

Edit code by function name, not text matching. The Edit tool fails when text isn't unique. This never does.

First: list_symbols

Before any edit, know what's in the file:

list_symbols({ file_path: 'src/api.ts' })

Why This Wins

| The Problem | Built-in Failure | syntax Solution | |-------------|------------------|-----------------| | Edit a function | Edit fails if code appears twice | edit_symbol finds by AST | | Find definition | Grep matches comments/strings | search_symbols finds actual symbols | | Rename everywhere | Miss references, break imports | rename_symbol handles all refs | | Move file | Broken imports everywhere | move_file updates all imports |

Quick Reference

| Task | Tool | |------|------| | See file structure | list_symbols | | Read one function | read_symbol | | Change a function | edit_symbol | | Change multiple symbols atomically | batch_edit_symbols | | Find a symbol | search_symbols | | Find all usages | find_references | | Rename everywhere | rename_symbol | | Move file safely | move_file | | Move function | move_symbol | | Who calls this? | get_callers | | What does this call? | get_callees | | Trace call chains | trace | | Find dead code | find_dead_code |

Common Workflows

Edit a Function

list_symbols({ file_path: 'src/utils.ts' })
read_symbol({ file_path: 'src/utils.ts', name_path: 'formatDate' })
edit_symbol({ file_path: 'src/utils.ts', name_path: 'formatDate', new_body: '...' })

Edit Multiple Symbols Atomically

When you need to change a function signature AND update all callers:

batch_edit_symbols({
  edits: [
    { file_path: 'src/api.ts', name_path: 'fetchUser', new_body: 'async function fetchUser(id: string, options?: Options) {...}' },
    { file_path: 'src/handlers.ts', name_path: 'handleUser', new_body: 'function handleUser() { fetchUser(id, { cache: true }); }' },
    { file_path: 'src/tests.ts', name_path: 'testFetchUser', new_body: 'test(...) { await fetchUser("123", {}); }' }
  ],
  dry_run: true  // Always preview first!
})

Why batch_edit_symbols?

  • All edits validated BEFORE any are applied
  • If one edit fails, NONE are applied (atomic)
  • Prevents half-updated code that doesn't compile

Safe Rename

rename_symbol({ old_name: 'oldName', new_name: 'newName', dry_run: true })
rename_symbol({ old_name: 'oldName', new_name: 'newName' })

Move File Without Breaking Imports

move_file({ source: 'src/utils.ts', destination: 'src/lib/utils.ts', dry_run: true })
move_file({ source: 'src/utils.ts', destination: 'src/lib/utils.ts' })

Understand Impact Before Changes

get_callers({ symbol_name: 'saveUser' })
trace({ symbol: 'handleRequest', direction: 'backward', depth: 3 })

Clean Up After Refactoring

remove_unused_imports({ file_path: 'src/handler.ts' })
organize_imports({ file_path: 'src/handler.ts' })

After Editing

  1. types.check_file() - verify no type errors
  2. test-runner.run_tests() - verify behavior unchanged

Supports

TypeScript, JavaScript, Python, Go, Rust

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