Transcript Handybook – Swift Presentation 7-8-14

Handybook:
Swift
Jayant Sani
Handybook Opinions
• “It’s like Ruby on Rails, for iOS!” – Nikita
• “A function should only do one thing and return one
value” - Justin
Brief History
• 1983: Objective-C is created
• 2000: Chris Lattner starts to work on LLVM,
a compiler for Objective-C during college
• 2007: LLVM project releases Clang
• 2010: Lattner begins working on Swift
• 2012: Apple ditches GCC, giving LLVM more
flexibility
• 2014: Apple announces Swift at WWDC
High-Level Overview
• Objective-C showing age – Smalltalk syntax
o Around since the 1980s
• Many modifications to make it modern
• Compile time vs Runtime (Static and dynamic)
Modern Language
Features
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No semicolons!
Static type system
Optional types
Functional Programming
Closures
Tuples
Generics
Automatic Reference Counting
Extensions
REPL (Playgrounds)
Designated and Convenience Initializers*
Static Type System
• Objective-C: Dynamic Typing, only object type was
(id) in early stages
Valid Objective-C code:
NSString *string = @”Handybook”;
id str = string
NSDictionary *dict= str;
dict[@”name”]
- Compiles fine, runtime error
• Swift: Static Typing
Guess what returns
Functional
• Objective-C: Blocks
• F*ckingblocksyntax.com
returnType (^blockName)(parameterTypes) =
^returnType(parameters) { statements };
• Swift: Functions are first class objects, Closures
(param1Type, param2Type, …) -> returnType
{ (params) -> returnType in
statements }
Generics
Extensions
Tuples
Drawbacks
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Xcode 6 is very, very, very buggy – beta
Proprietary
Operator overloading – controversial
No pointers – errors, functions
Dealing with JSON Data
Message passing vs. vtable
Vague constants – “let” keyword
No access modifiers
Objective-C without Smalltalk