Introducing functional programming basic concepts via F#.

1. Functional Programming
- Introducing F#
06/15/2012

2. Example
 Give me a list of numbers from 1 to 100.
Tell me how ? Tell me what ?

3. What?
Functional programming is a programming paradigm
that treats computation as the evaluation of
mathematical functions and avoids state and mutable
data.
y = f (x)
A function is a transformation. It transforms one or more inputs into exactly
one output.

4. Why?
 Succinct & simpler programs
 Small code base, low dev/maintenance cost.
 A number of powerful new ways to structure and
reason about programs.
 Immutability
 High order function
 Pattern Matching
…

5. How?
 Immutability
 Type Inference
 Recursion
 High Order Functions
 Partial Application
 Pattern Matching
 Unit of Measure

6. Immutability
By default, values are immutable. Use keyword
mutable to mark it as mutable.

7. Type Inference
 F# can deduce data types automatically.
 Type annotation is necessary in certain case.

8. Recursion
• Functional programming prefers recursion to
imperative for-each loops.
• Prefer tail recursion to avoid stack overflow

9. High order Function
 Functions in F#

10. High order Function
 Functions as First Class Member
 Functions that accept a function as a parameter or
returns a function

11. High Order Function
 Map
 Fold
 Zip
 Filter
 Pipeline
 Function Composition
 Partial Application

12. Pattern Match
 Compare data with a logical structure
 Decompose data into its constituent parts
 Extract information from constructs in various
ways

13. Unit of Measure
 Floating point and signed integer values in F# can
have associated units of measure.
 Compile time checking.

14. Functional Programming in Real World
 Erlang developed in Ericsson widely used in T-
Mobile, Facebook....
 Industry
 Communication
 Finance industry
 Scientific computation
 AI
 Languages support FP
 Haskell
 Scala
 Python
 Clojure
 …

15. Resources
 The F# Survival Guide
 Functional Programming for the Real World