*-Oriented Programming

Presented by Graham Lee at #Pragma 2015

Transcript

1. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions *–Oriented Programming Graham Lee December 1, 2015 Graham Lee *–Oriented Programming
2. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Introduction Function–oriented Objects Object–oriented Functions Conclusions Graham Lee *–Oriented Programming
3. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions How can we Orient Programming? What is Object–Orientation? What is Functional Programming? What’s a programming paradigm, and where can I buy one? Graham Lee *–Oriented Programming
4. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Paradigmatic Programming How does the way we think about our problems define the solutions? Do programming tools have much bearing on this? Graham Lee *–Oriented Programming
5. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Paradigmatic Thinking Tools can support that thinking but don’t shape it This is all about how we attack our problems Graham Lee *–Oriented Programming
6. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Functional points Given a Cartesian representation of a point x, y, find its distance from the origin and angle from the x–axis. Graham Lee *–Oriented Programming
7. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Functional points—attempt 1 Point radius :: float, float → float Point radius(x, y) = x2 + y2 Point angle :: float, float → float Point angle(x, y) = arctan(x/y) Graham Lee *–Oriented Programming
8. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Functional points—attempt 2 Point :: float, float, operation → float Point(x, y, Radius) = x2 + y2 Point(x, y, Angle) = arctan(x/y) Graham Lee *–Oriented Programming
9. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Functional points—attempt 3 Point :: float, float, operation → Function Point(x, y, Radius) = Point radius Point(x, y, Angle) = Point angle Graham Lee *–Oriented Programming
10. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Functional points—tidying up Point :: float, float → operation → Function Point(x, y) is a Constructor for an object, p p(operation) is a Message, which takes a Selector and returns a Method. Point (r, θ) could also be a Constructor. . . Graham Lee *–Oriented Programming
11. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Object–oriented compiler Write a compiler that takes source code in some language and creates an executable. If it encounters malformed source code, it should report an error and should not produce an executable. Graham Lee *–Oriented Programming
12. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Object–oriented compiler—attempt 1 Compiler +compile(source:String): Optional<Executable> +getErrors(): Array<CompilerError> Graham Lee *–Oriented Programming
13. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Object–oriented compiler—attempt 2 Compiler +compile(source:String,errorReporter:ErrorReporter): Optional<Executable> ErrorReporter +reportError(error:CompilerError): void Graham Lee *–Oriented Programming
14. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Object–oriented compiler—attempt 3 Tokeniser +tokenise(source:String,errorReporter:ErrorReporter): Optional<TokenisedSource> ErrorReporter +reportError(error:CompilerError): void Compiler +compile(source:TokenisedSource,errorReporter:ErrorReporter): Optional<AssemblyProgram> Assembler +assemble(program:AssemblyProgram,errorReporter:ErrorReporter): Optional<BinaryObject> Linker +link(objects:Array<BinaryObject>,errorReporter:ErrorReporter): Optional<Executable> Graham Lee *–Oriented Programming
15. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions So what just happened? We took functions describing points, and applied the principles of functional programming until what we had were objects. We took an object describing a compiler, and applied the principles of object–oriented programming until what we had were functions. Graham Lee *–Oriented Programming
16. Outline Introduction Function–oriented Objects Object–oriented Functions Conclusions Conclusions *–oriented programming describes your thought process The tools can constrain you, they can’t lead your thought. You’re going to have to bring your own thinking. Graham Lee *–Oriented Programming