metaprogramming

Teach Ruby developers metaprogramming for DSLs and dynamic methods.

3|Updated Jan 9, 2026

Search Tags:#ruby #metaprogramming #dsl #method_missing #define_method #class_eval #instance_eval

Ready to run

npx skills add https://github.com/bastos/ruby-plugin-marketplace --skill metaprogramming-bastos

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: metaprogramming
Source: https://github.com/bastos/ruby-plugin-marketplace/tree/main/plugins/ruby/skills/metaprogramming
Command: npx skills add https://github.com/bastos/ruby-plugin-marketplace --skill metaprogramming-bastos

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Ruby metaprogramming enables developers to create flexible interfaces, reduce boilerplate, and build expressive DSLs. This guide helps you understand when and how to use metaprogramming techniques to craft maintainable APIs.

Core Features & Use Cases

Dynamic method creation with define_method for runtime behavior
Method_lookup customization via method_missing and respond_to_missing?
ClassEval/ModuleEval and instance_eval for targeted scope and DSLs
Hooks, callbacks, and DSL creation for expressive configurations
Practical examples: building a tiny DSL, dynamic attribute accessors, and small domain-focused languages

Quick Start

Describe a minimal Ruby DSL using metaprogramming to configure a class.

Frequently Asked Questions about metaprogramming

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I build a DSL in Ruby using metaprogramming?▼

You build a Ruby DSL using metaprogramming by applying instance_eval and class_eval to establish targeted scopes, coupled with dynamic method creation to yield expressive, domain-focused configurations.

When should I use method_missing vs define_method for dynamic methods?▼

Use define_method for predictable dynamic methods created at runtime, and method_missing for undefined method interception; always pair method_missing with respond_to_missing? for proper safety checks.

What is the difference between class_eval and instance_eval when creating DSLs?▼

instance_eval evaluates code in the context of an individual object for instance-level DSLs, while class_eval executes within a class definition scope to define methods and hooks across all instances.

How do metaprogramming hooks and callbacks reduce boilerplate in Ruby classes?▼

Metaprogramming hooks and callbacks reduce boilerplate by automatically triggering behavior when classes or modules are modified, allowing flexible APIs without repetitive manual method definitions.

What are the limitations of using Ruby metaprogramming for flexible APIs?▼

Ruby metaprogramming introduces code complexity and potential debugging difficulties; proper safety checks are required for method_missing, and excessive dynamic behavior can reduce readability and maintainability.