functional_programming_vocabulary.md

Vocabulary of functional programming

• first-class function
  • when you can store a function in a variable
• anonymous function
  • a function without a name
• closures and pure functions
  • closure - function with at least one free variable (variable defined elsewhere)
  • pure function - a function where the variables are bound to the function's scope
    • also, a function that always returns the same output for some input
• higher-order function
  • a function that takes a function as input, or returns a function as output
• immutable/mutable
  • immutable - value that cannot change
  • mutable - value that can change
• imperative/declarative
  • imperative - telling the computer what to do and how to do it
  • declarative - telling the computer what to do, but not how to do it
• currying/partial application
  • currying - splitting a function into several functions of one parameter each
    • function add(x, y) {return x + y;} --> function(x) { return function(y) { return x + y; } }
• unary function
  • a function which takes one input
• aggregate function (aka reduction function)
  • a function which takes a running total and a new element, and incorporates the new element into a new total
• predicate function
  • a function which returns true or false
• map, filter, reduce
  • map - apply a unary function to each member of a collection
  • filter - select elements from a collection that have some property based on a predicate function
  • reduce - incorporate elements of a collection into some aggregate using an aggregate function
• recursion
  • when a function calls itself
• tail-call recursion
  • when a function calls itself as the last thing the function does.

Thanks this is really applicable to the class I'm taking.