Function object
In Ruby, several objects can be considered function objects, in particular Method and Proc objects. Ruby also has two kinds of objects that can be thought of as semi-function objects: UnboundMethod and block. UnboundMethods must first be bound to an object (thus becoming a Method) before they can be used as a function object. Blocks can be called like function objects, but to be used in any other capacity as an object (e.g. passed as an argument) they must first be converted to a Proc. More recently, symbols (accessed via the literal unary indicator codice_35) can also be converted to codice_36s. Using Ruby's unary codice_37 operator—equivalent to calling codice_38 on an object, and assuming that method exists—the Ruby Extensions Project created a simple hack.
Ruby MRI
Matz's Ruby Interpreter or Ruby MRI (also called CRuby) was the reference implementation of the Ruby programming language named after Ruby creator Yukihiro Matsumoto ("Matz"). Until the specification of the Ruby language in 2011, the MRI implementation was considered the "de facto" reference, especially since an independent attempt to create the specification (RubySpec) had failed. Starting with Ruby 1.9, and continuing with Ruby 2.x and above, the official Ruby interpreter has been YARV ("Yet Another Ruby VM").