F#Steven Anderson

Tyler Stigliano

Introduction History Purpose Main Features Code Examples Final Remarks

Overview

Targets .NET framework◦ Intertwine with other .NET languages (C#, C++,

VB)

Variant of ML◦ Largely compatible with OCaml syntax

Functional Language◦ With object oriented and imperative disciplines

Introduction

Developed by Don Syme

Being developed at Microsoft Development Division

Releases◦ Version 1.0 – 2005◦ Version 2.0 – 2010

History

To combine multiple programming paradigms into one

Functional Programming◦ Scientific modelers, mathematicians, financial

institutions and more◦ Heavy number crunching

Get problems solved in a concise manner◦ Higher-Order functions◦ Type Inference

Purpose

Banking Firm in Europe◦ Uses mathematic models to manage investment

portfolios◦ Built small units of functionality and combined them

to create a model◦ Claims to have sped development by 50%

Quotes◦ “We could not have developed 200 models in two

years without F# and Visual Studio” ◦ “With a functional language like F#, we can create

simple, compositional code, and so we naturally see a high degree of code reuse”

Purpose cont. (Use Case #1)

Major energy company in UK◦ Application to balance national power generation

schedule Benefits

◦ “Sweet spot” for algorithmically complex analysis of large data sets

◦ Units of measurements◦ Used c++ to build interface; injected F# to do

calculations◦ Code reduction◦ Parallelism

Purpose cont. (Use Case #2)

Characteristics◦ Strongly Typed◦ Immutable vs. Mutable◦ Eager evaluation◦ Parallelism

Encompasses:◦ Functional Programming◦ Imperative Programming◦ Object-Oriented Programming

Main Features

Functional Programming◦ Functions as Values◦ Function Composition◦ Type Inference◦ Automatic Generalization◦ Pattern Matching◦ Lambda Expressions◦ Code Quotations

Main Features

Imperative Programming◦ Control Flow◦ Arrays◦ Mutable Collections◦ Basic I/O◦ Exception Handling

Object-Oriented Programming ◦ .NET Framework Object Model◦ Data Encapsulation◦ Operator Overloading◦ Type Extensions

Main Features

Structure of F# program

Code Examples

Immutable Variables

Code Examples

Mutable Data

Code Examples

Function Declaration

Code Examples

Function Return Values

Code Examples

Recursion

Code Examples

Nested Functions

Code Examples

Pattern Matching

Code Examples

Tuples and Records

Code Examples

Tuples and Records cont.

Code Examples

Arrays

Code Examples

Loops

Code Examples

Additional Features- Higher-Order Function- Option Types- Lists & Sequences- Classes- Advanced Data Structures

Code Examples

Current Compilers◦ Sharp Develop (www.icasharpcode.net)◦ MS Visual Studio 2010 (www.msdn.com)

Final Remarks

http://en.wikibooks.org/wiki/F_Sharp_Programming/Basic_Concepts

http://research.microsoft.com/en-us/um/cambridge/projects/fsharp/

http://blogs.msdn.com/b/dsyme/archive/2011/01/12/f-for-energy-trading-and-energy-portfolio-optimization.aspx

http://msdn.microsoft.com/en-us/vstudio/hh388569.aspx

References

F#Steven Anderson

Tyler Stigliano