Developing Swift - Moving towards the future

Developing Swift
Moving towards the future

About Inaka
• Started in 2010.
• Acquired by Erlang Solutions in 2014.
• We build end-to-end applications with Erlang, Ruby, Web,
iOS and Android components.
• We develop highly concurrent application servers such as
Whisper and TigerText.
• We're active contributors to the open-source community.

About Me
• Pablo Villar.
• iOS Developer.
• Have been working at Inaka for last 2 years.
• Have been working as iOS dev for last 4 years.
• Clean code lover!

What’s Swift?
Why Swift?
How to Swift?
What’s behind Swift?
What’s Swift for?

A little bit of history…
Early 1980's Objective-C
2007 iPhone is born
Late 1980's NeXT license
AppKit, FoundationKit
1997 Apple purchases NeXT
2010 iPad is born
2015 Watch is born

A little bit of history…
Early 1980's Objective-C
2007 iPhone is born
Late 1980's NeXT license
AppKit, FoundationKit
1997 Apple purchases NeXT
2010 iPad is born
2015 Watch is born
2014
Swift

2007~2015 (last 8 years)
… ?
IPHONE
IPAD
WATCH
IPOD TOUCH

OBJ-C SWIFT
1980 - Nowadays 2014 - Nowadays
to be deprecated… (?) to keep growing…

A very little bit of history of Swift…
June 2014 Swift 1.0
April 2015 Swift 1.2
October 2015 Swift 2.0
Today
No backwards
compatibility
OPEN
SOURCE!

BE TOLERANT!
Y U NO CLEAR?!?!?!

BE CHALLENGED!
Last… Not least.

Now… What you’ve been waiting for…

code!

code!
wasn’t it…?

code!
SAFETY
Optionals
wasn’t it…?

code!
SAFETY
Optionals
String?
String
nil
wasn’t it…?

Why Optionals?
Things can be nullable
You need a mechanism to properly deal with that
Swift is statically typed
+

Why Optionals?
+
String “A regular String, it can’t be nil”

Why Optionals?
+
String “A regular String, it can’t be nil”
String? “A String that can be nil”
Optional Type

String? “A String that can be nil”

String? “A
An Optional that can be a String
…or can eventually be nil
String?
String
nil

String? “A
String?
String
nil Behind the scenes…
enum Optional<T> {
case None // nil
case Some(T) // a T
}

String? “A
String?
String
nil Behind the scenes…
enum Optional<T> {
case None // nil
case Some(T) // a T
}
Optional<String>

Int?
Int
nil
A little, yet valuable example…

Int?
Int
nil
var age: Int?

Int?
Int
nil
// We prompt the user to enter his/her age.
var age: Int?

Int?
Int
nil
func greetingForPersonWithAge(age: Int) -> String {
var age: Int?
switch age {
case 0...2: return "Hello baby!"
case 3...5: return "How are you doing, toddler?”
case 6...12: return "What's up, kid?"
case 13...18: return "Yo, what's up?"
default: return "Hello, mister!"
}
}

Int?
Int
nil
var age: Int?
let greeting = greetingForPersonWithAge(age)
println(greeting)
switch age {
}
}

Int?
Int
nil
func
var
println(
}
}

Int?
Int
nil
var age: Int?
// Int? and Int are not compatible,
// You have to deal with it
println(greeting)
}
}

But, how to…
?
var age: Int? = nil
if let knownAge = age {
let greeting = greetingForPersonWithAge(knownAge)
println(greeting)
} else {
println("Hello") // No age.
}

But, how to…
?
var age: Int? = nil
println(greeting)
} else {
}
Init to nil by default

But, how to…
?
var age: Int? = nil
println(greeting)
} else {
}
"Unwrap" the optional

But, how to…
?
var age: Int? = nil
println(greeting)
} else {
}
Use the unwrapped one,
which is NOT an optional
but an Int

But, how to…
?
var age: Int? = nil
println(greeting)
} else {
}
but an Int
Deﬁne a separated behavior
to deal with nil values

But, how to…
?
var age: Int? = nil
println(greeting)
} else {
}
but an Int
Deﬁne a separated behavior
to deal with nil values
SAFETY

var age: Int?
println(greeting)
} else {
println("Hello") // Or show alert. Or whatever.
}
switch age {
}
}
(Let’s get ALL the juice from it!)

var age: Int?
println(greeting)
} else {
println("Hello") // Or show alert. Or whatever.
}
}
}
(Let’s get ALL the juice from it!)
From this point on, we don’t have
to worry about nullability ever again!

In conclusion…
• Swift changes the way we use to think when it comes to
develop mobile apps.

In conclusion…
• The language has just been born and it’s growing really
fast.

In conclusion…
• We’re still in a phase in which there are many bugs and
downsides.
fast.

In conclusion…
• We’re still in a phase in which there are many bugs and
downsides.
fast.
• But still, promises are big! Swift is the future.

For more info… Check these out!
https://developer.apple.com/videos/wwdc/2014/
https://developer.apple.com/videos/wwdc/2015/
https://developer.apple.com/swift/resources/
http://www.objc.io/
Cool blogs to learn from…
http://nshipster.com/
Inaka’s webpage:
http://inaka.net/
http://inaka.net/blog

Developing Swift - Moving towards the future

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