AST Manipulation

Expert skill for abstract syntax tree design, traversal, transformation, and manipulation patterns

509 stars

Best use case

AST Manipulation is best used when you need a repeatable AI agent workflow instead of a one-off prompt.

Expert skill for abstract syntax tree design, traversal, transformation, and manipulation patterns

Teams using AST Manipulation should expect a more consistent output, faster repeated execution, less prompt rewriting.

When to use this skill

  • You want a reusable workflow that can be run more than once with consistent structure.

When not to use this skill

  • You only need a quick one-off answer and do not need a reusable workflow.
  • You cannot install or maintain the underlying files, dependencies, or repository context.

Installation

Claude Code / Cursor / Codex

$curl -o ~/.claude/skills/ast-manipulation/SKILL.md --create-dirs "https://raw.githubusercontent.com/a5c-ai/babysitter/main/library/specializations/programming-languages/skills/ast-manipulation/SKILL.md"

Manual Installation

  1. Download SKILL.md from GitHub
  2. Place it in .claude/skills/ast-manipulation/SKILL.md inside your project
  3. Restart your AI agent — it will auto-discover the skill

How AST Manipulation Compares

Feature / AgentAST ManipulationStandard Approach
Platform SupportNot specifiedLimited / Varies
Context Awareness High Baseline
Installation ComplexityUnknownN/A

Frequently Asked Questions

What does this skill do?

Expert skill for abstract syntax tree design, traversal, transformation, and manipulation patterns

Where can I find the source code?

You can find the source code on GitHub using the link provided at the top of the page.

SKILL.md Source

# AST Manipulation Skill

## Overview

Expert skill for abstract syntax tree design, traversal, transformation, and manipulation patterns.

## Capabilities

- Design typed AST node hierarchies
- Implement visitor and transformer patterns
- Build AST rewriting systems
- Implement AST diffing and patching
- Generate AST pretty-printers and formatters
- Support AST serialization (JSON, binary)
- Implement pattern matching on AST structures
- Design span/location tracking systems

## Target Processes

- ast-design.js
- semantic-analysis.js
- ir-design.js
- code-generation-llvm.js
- lsp-server-implementation.js
- macro-system-implementation.js

## Dependencies

None (core skill)

## Usage Guidelines

1. **Node Design**: Design immutable AST nodes with clear ownership semantics
2. **Location Tracking**: Include source spans on all nodes from the beginning
3. **Visitor Pattern**: Implement visitor pattern for extensible traversal
4. **Transformation**: Use transformer pattern for AST-to-AST transformations
5. **Serialization**: Support both human-readable (JSON) and efficient (binary) serialization

## Output Schema

```json
{
  "type": "object",
  "properties": {
    "nodeTypes": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "name": { "type": "string" },
          "fields": { "type": "array" },
          "parent": { "type": "string" }
        }
      }
    },
    "visitors": {
      "type": "array",
      "items": { "type": "string" }
    },
    "transformers": {
      "type": "array",
      "items": { "type": "string" }
    },
    "generatedFiles": {
      "type": "array",
      "items": { "type": "string" }
    }
  }
}
```