Ruby

Use when working with Ruby metaprogramming features including dynamic method definition, method_missing, class_eval, define_method, and reflection.

Use when working with Ruby gems, Bundler for dependency management, creating gemspecs, and publishing gems to RubyGems.

Use when working with Ruby's standard library including Enumerable, File I/O, Time/Date, Regular Expressions, and core classes.

Use when working with Ruby blocks, procs, lambdas, and functional programming patterns including closures and higher-order functions.

Use when working with Ruby's object-oriented programming features including classes, modules, inheritance, mixins, and method visibility.