Learning Functional Programming in Go

Lambda expression ingredients

A lambda expression is an unnamed block of code with parameters.

A lambda expression consists of three things:

• A block of code x + 2
• Parameters x
• Values for the free variables (not defined inside the code block) 5

Lambda calculus uses the following three concepts to describe how to perform a unit of computation:

• Abstraction (defining a function)
• Binding (defining a variable)  
• Application (executing a function)

Variables that are unbound are referred to as free variables. Computation is achieved by performing single steps of reduction:

1. Alpha reduction  
2. Beta reduction
3. Eta reduction

Consider the following untyped Lambda calculus statement:

(λx.xx)(λx.xx)

The lambda symbol (from whence the name is derived) ...