Code - Functional programming (FP) - Collection Operations

Functional programming (FP) defines standard operations on collections.

It is a declarative paradigm that treats computation as the evaluation of mathematical functions.

Most of the operations you perform on collections can be accomplished with five simple functions:

• map
• filter
• mergeAll
• reduce
• zip

These five functions hold a key to simplifying asynchronous programming and avoid race conditions, propagate and handle asynchronous errors, and sequence events and requests.

Multiple invocation of a function at different point of time will always return same output as long as input remains same. It makes easy to understand and predict behavior of program.

With functional programming (FP), the code should be organized around:

• pure functions that take data and transform it, without modifying any shared state.
• around how data flows between these pure functions to produce output data.

The application of several function programming operations creates a composite type called a Algebraic data type

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imperative vs Functional

• Functional Programming - Sum
• Functional Programming - flatMap

JVM based Functional Programming Languages

• Scala
• Clojure
• Groovy

• ReactiveX - ReactiveX: A library for composing asynchronous and event-based programs using observable sequences for the Java VM, Javascript
• https://ramdajs.com/ - Javascript

• Cursus - Introduction to Functional Programming
• Doc -Why Functional Programming Matters John Hughes The University, Glasgow
• https://docs.python.org/2/howto/functional.html
• Fp Operation catalog
• Functional_programming