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![INTRODUCTION
GENERICS
▸ Grouping of similar functionality into a single Thing
▸ Parametric Polymorphism [not Just polymorphism]
▸ Compile Time / Static Polymorphism](https://image.slidesharecdn.com/generics-161110195042/85/Generics-programming-in-Swift-4-320.jpg)
![INTRODUCTION
GENERICS
▸ Grouping of similar functionality into a single Thing
▸ Parametric Polymorphism [not Just polymorphism]
▸ Compile Time / Static Polymorphism](https://image.slidesharecdn.com/generics-161110195042/75/Generics-programming-in-Swift-4-2048.jpg)
Uploaded byVijaya Prakash Kandel
Generics programming in Swift
The document discusses generic programming, comparing language support and highlighting concepts like parametric polymorphism, type safety, and protocol-oriented programming in Swift. It emphasizes the advantages of generics in reducing redundancy and ensuring type safety, while also addressing common pitfalls and type constraints. Ultimately, it illustrates the strong support for generics within Swift's standard library, enhancing functionality and efficiency in coding.
Generics programming in Swift
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- 2. TEXT ▸ A ComparativeStudy of Language Support for Generic Programming (R Gracia 2003) ▸ An Extended Comparative Study of Language Support for Generic Programming (R Gracia 2007)
- 3. AGENDA ▸ Refine Queue ▸Concepts/Protocols ▸ Common errors and why? ▸ Protocol Oriented Programming (IF⏲ ) ▸ Finale: Swift vs Haskell in Generics
- 4. INTRODUCTION GENERICS ▸ Grouping ofsimilar functionality into a single Thing ▸ Parametric Polymorphism [not Just polymorphism] ▸ Compile Time / Static Polymorphism
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- 9. TEXT 1000’S OF THESE ▸Cant be extended
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- 12. TEXT ANALYSE ▸ all valuesemantics conform to Any Protocol by default ▸ Is it Generic?
- 13. TEXT . ▸ NOT GENERIC ▸Type Erasure Model ▸ Heterogeneous set capable ▸ Objectie-C NSArray is somehow similar to this
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- 15. TEXT . ▸ Generic ▸ TypeSafe ▸ Homogeneous set capable ▸ T==> type deduction from call site
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- 17. TEXT SO WHAT?? ▸ Reducesredundancy
- 18. TEXT SO WHAT?? ▸ TypeSafety
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- 20. TEXT SO WHAT?? ▸ Capabilitycan be extended beyond the authors intention ▸ Originates from Set theory. Highly useful for FPs.
- 21. TEXT SO WHAT FORUS???? ▸ Swift uses Generics all over the Standard Library ▸ Swift has a great support for Generics ▸ Generics are awesome when all the <> brackets and T: U: make sense
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- 25. TEXT PROPER TYPED GENERICS +is not defined on all types: unfortunately!!!
- 26. + CONCEPTS ▸ + meanslhs and rhs can be added. It is a concept. ▸ In C++ are just documented. No language support. YUK
- 27. TEXT CONCEPT == PROTOCOL ▸Protocol to our rescue.
- 28. TEXT SO…… ▸ Expressive ▸ NoLies to the compiler
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- 33. TEXT HOW IT COMPILES? ▸during compile time a concrete function is created in place of generic function. This is Separate Compilation. ▸ LLVM is smarter than this.
- 34. TEXT TYPES ▸ A groupingof data structure ▸ Int, String, NavigationBarAppereance, classes.
- 35. TEXT TYPES ▸ Protocols thatare complete by themselves are proper types
- 36. TEXT WHAT ARE NOTTYPES? ▸ Items that can not completely defined in isolation ▸ Don’t know what is the type of Self until conformed by some concrete Type
- 37. TEXT WHAT ARE NOTTYPES? ▸ Items that can not completely defined in isolation ▸ Element is unknown unless conformed by somebody
- 38. TEXT SO.. ▸ They areGeneric placeholders (Incomplete Types) ▸ so is Array, ▸ But not Array<Int>. Its a complete Type.
- 39. TEXT THUS ▸ Protocols withSelf requirement or associatedType requirement are not complete by themselves ▸ Thus, they cant be used like a Type ▸ They can be used to constrain other Types ▸ Examples: ▸ Queue<T> ▸ Array<T>
- 40. TEXT 2. TYPE CONSTRAINTS Reducefunction over a Collection Type only when the elements are SignedInteger
- 41. TEXT NOTE: ▸ Make notethat Swift provided “T:Comparable” which specifies T can be anything that conforms to a concept/ protocol Comparable. Whereas, T == Int would mean T must be a Integer type.
- 42. TEXT GENERICS VS LOOKSGENERICS
- 43. TEXT TYPE ERASURE MODEL ▸Generic Placeholder gives Type safety and feedback on code analysis ▸ Concrete Type parameter casts the provided argument into the Type method accepts. Hence, losing Type information. Type Erasure Polymorphism model or Not So Swift Model
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- 46. TEXT ARRAY OF PROTOCOL ▸Array of Concrete Type cannot be implicitly converted to Array of Another Type ▸ But a single Concrete Type can be converted to
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- 48. ▸ Protocol area special construct which occupies 40 bytes ▸ Int are 8 bytes on 64 bit machine ▸ Array<Int> == Array<8byte contagious memory> ▸ Array<AType> == Array<40Byte contagious memory> ▸ Swift wont transform :=> performance, memory, type loss TEXT WHY?
- 49. TEXT MIXIN, DEFAULT IMPLEMENTATION ▸DEMO ▸ Protocol Oriented Programming ▸ Avoid Subclassing ▸ Careful about: Static vs Dynamic Dispatch!!!!
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- 53. TEXT AT THE CALLSITE
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- 56. TEXT WHAT WE GOT! ▸Protocol Oriented Programming ▸ We can subclass only from 1 parent. This makes multiple inheritance easy without actually inheriting ▸ Retroactive modeling (WHAT)
- 57. TEXT RETROATTIVE MODELING ▸ Abilityto add functionality after the Type has been defined completely. ▸ Even though Array is made by Swift Team we were able to extend it with useful function after 2 years finally.
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- 59. TEXT Great Support ForGenerics
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- 61. REFERENCES ▸ Programming". http://www.osl.iu.edu/publications/prints/2005/ garcia05:_extended_comparing05.pdf.N.p., 2016. Web. 22 May 2016. ▸ "Generics In Swift, Part 2 · Episteme And Techne". Austinzheng.com. N.p., 2015. Web. 23 May 2016. ▸ Cook, Nate. "Are Swift Generics Separately Compiled?". Stackoverflow.com. N.p., 2016. Web. 24 May 2016. ▸ "Mixin". Wikipedia. N.p., 2016. Web. 24 May 2016. ▸ Tsai, Michael. "Michael Tsai - Blog - How Swift Implements Generics". Mjtsai.com. N.p., 2016. Web. 24 May 2016.