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scala: consistent code format
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@ -220,19 +220,19 @@ def foo(x: Int): Int = {
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1 to 5
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1 to 5
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val r = 1 to 5
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val r = 1 to 5
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r.foreach( println )
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r.foreach(println)
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r foreach println
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r foreach println
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// NB: Scala is quite lenient when it comes to dots and brackets - study the
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// NB: Scala is quite lenient when it comes to dots and brackets - study the
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// rules separately. This helps write DSLs and APIs that read like English
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// rules separately. This helps write DSLs and APIs that read like English
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(5 to 1 by -1) foreach ( println )
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(5 to 1 by -1) foreach (println)
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// A while loops
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// A while loops
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var i = 0
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var i = 0
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while (i < 10) { println("i " + i); i+=1 }
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while (i < 10) { println("i " + i); i += 1 }
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while (i < 10) { println("i " + i); i+=1 } // Yes, again. What happened? Why?
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while (i < 10) { println("i " + i); i += 1 } // Yes, again. What happened? Why?
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i // Show the value of i. Note that while is a loop in the classical sense -
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i // Show the value of i. Note that while is a loop in the classical sense -
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// it executes sequentially while changing the loop variable. while is very
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// it executes sequentially while changing the loop variable. while is very
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@ -241,19 +241,19 @@ i // Show the value of i. Note that while is a loop in the classical sense -
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// A do while loop
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// A do while loop
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do {
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do {
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println("x is still less than 10");
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println("x is still less than 10")
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x += 1
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x += 1
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} while (x < 10)
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} while (x < 10)
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// Tail recursion is an idiomatic way of doing recurring things in Scala.
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// Tail recursion is an idiomatic way of doing recurring things in Scala.
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// Recursive functions need an explicit return type, the compiler can't infer it.
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// Recursive functions need an explicit return type, the compiler can't infer it.
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// Here it's Unit.
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// Here it's Unit.
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def showNumbersInRange(a:Int, b:Int):Unit = {
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def showNumbersInRange(a:Int, b:Int): Unit = {
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print(a)
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print(a)
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if (a < b)
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if (a < b)
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showNumbersInRange(a + 1, b)
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showNumbersInRange(a + 1, b)
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}
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}
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showNumbersInRange(1,14)
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showNumbersInRange(1, 14)
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// Conditionals
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// Conditionals
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@ -307,13 +307,13 @@ s(1)
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(a, 2, "three")
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(a, 2, "three")
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// Why have this?
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// Why have this?
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val divideInts = (x:Int, y:Int) => (x / y, x % y)
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val divideInts = (x: Int, y: Int) => (x / y, x % y)
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divideInts(10,3) // The function divideInts gives you the result and the remainder
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divideInts(10, 3) // The function divideInts gives you the result and the remainder
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// To access the elements of a tuple, use _._n where n is the 1-based index of
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// To access the elements of a tuple, use _._n where n is the 1-based index of
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// the element
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// the element
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val d = divideInts(10,3)
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val d = divideInts(10, 3)
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d._1
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d._1
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@ -416,8 +416,8 @@ val otherGeorge = george.copy(phoneNumber = "9876")
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def matchPerson(person: Person): String = person match {
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def matchPerson(person: Person): String = person match {
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// Then you specify the patterns:
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// Then you specify the patterns:
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case Person("George", number) => "We found George! His number is " + number
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case Person("George", number) => "We found George! His number is " + number
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case Person("Kate", number) => "We found Kate! Her number is " + number
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case Person("Kate", number) => "We found Kate! Her number is " + number
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case Person(name, number) => "We matched someone : " + name + ", phone : " + number
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case Person(name, number) => "We matched someone : " + name + ", phone : " + number
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}
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}
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val email = "(.*)@(.*)".r // Define a regex for the next example.
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val email = "(.*)@(.*)".r // Define a regex for the next example.
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@ -448,7 +448,7 @@ def matchEverything(obj: Any): String = obj match {
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case List(1, b, c) => s"Got a list with three elements and starts with 1: 1, $b, $c"
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case List(1, b, c) => s"Got a list with three elements and starts with 1: 1, $b, $c"
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// You can nest patterns:
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// You can nest patterns:
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case List(List((1, 2,"YAY"))) => "Got a list of list of tuple"
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case List(List((1, 2, "YAY"))) => "Got a list of list of tuple"
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}
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}
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// In fact, you can pattern match any object with an "unapply" method. This
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// In fact, you can pattern match any object with an "unapply" method. This
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@ -495,7 +495,7 @@ sSquared.reduce (_+_)
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// The filter function takes a predicate (a function from A -> Boolean) and
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// The filter function takes a predicate (a function from A -> Boolean) and
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// selects all elements which satisfy the predicate
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// selects all elements which satisfy the predicate
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List(1, 2, 3) filter (_ > 2) // List(3)
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List(1, 2, 3) filter (_ > 2) // List(3)
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case class Person(name:String, age:Int)
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case class Person(name: String, age: Int)
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List(
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List(
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Person(name = "Dom", age = 23),
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Person(name = "Dom", age = 23),
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Person(name = "Bob", age = 30)
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Person(name = "Bob", age = 30)
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@ -596,7 +596,7 @@ import scala.collection.immutable._
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import scala.collection.immutable.{List, Map}
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import scala.collection.immutable.{List, Map}
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// Rename an import using '=>'
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// Rename an import using '=>'
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import scala.collection.immutable.{ List => ImmutableList }
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import scala.collection.immutable.{List => ImmutableList}
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// Import all classes, except some. The following excludes Map and Set:
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// Import all classes, except some. The following excludes Map and Set:
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import scala.collection.immutable.{Map => _, Set => _, _}
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import scala.collection.immutable.{Map => _, Set => _, _}
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