Merge pull request #2476 from sjrd/tabbed-code-tour-tuples

Enable tabbed Scala 2/3 code in tour/tuples.

Author: sjrd

_tour/tuples.md

@@ -18,62 +18,106 @@ Tuples are especially handy for returning multiple values from a method.
 
 A tuple with two elements can be created as follows:
 
+{% tabs tuple-construction %}
+
+{% tab 'Scala 2 and 3' for=tuple-construction %}
 ```scala mdoc
-val ingredient = ("Sugar" , 25)
+val ingredient = ("Sugar", 25)
 ```
+{% endtab %}
 
-This creates a tuple containing a `String` element and an `Int` element.
+{% endtabs %}
 
-The inferred type of `ingredient` is `(String, Int)`, which is shorthand
-for `Tuple2[String, Int]`.
+This creates a tuple containing a `String` element and an `Int` element.
 
-To represent tuples, Scala uses a series of classes: `Tuple2`, `Tuple3`, etc., through `Tuple22`.
-Each class has as many type parameters as it has elements.
+The inferred type of `ingredient` is `(String, Int)`.
 
 ## Accessing the elements
 
-One way of accessing tuple elements is by position.  The individual
-elements are named `_1`, `_2`, and so forth.
+{% tabs tuple-indexed-access class=tabs-scala-version %}
+
+{% tab 'Scala 2' for=tuple-indexed-access %}
+One way of accessing tuple elements is their positions.
+The individual elements are named `_1`, `_2`, and so forth.
 
 ```scala mdoc
 println(ingredient._1) // Sugar
 println(ingredient._2) // 25
 ```
+{% endtab %}
+
+{% tab 'Scala 3' for=tuple-indexed-access %}
+One way of accessing tuple elements is their positions.
+The individual elements are accessed with `tuple(0)`, `tuple(1)`, and so forth.
+
+```scala
+println(ingredient(0)) // Sugar
+println(ingredient(1)) // 25
+```
+{% endtab %}
+
+{% endtabs %}
 
 ## Pattern matching on tuples
 
 A tuple can also be taken apart using pattern matching:
 
+{% tabs tuple-extraction %}
+
+{% tab 'Scala 2 and 3' for=tuple-extraction %}
 ```scala mdoc
 val (name, quantity) = ingredient
-println(name) // Sugar
+println(name)     // Sugar
 println(quantity) // 25
 ```
+{% endtab %}
+
+{% endtabs %}
 
 Here `name`'s inferred type is `String` and `quantity`'s inferred type
 is `Int`.
 
 Here is another example of pattern-matching a tuple:
 
+{% tabs tuple-foreach-patmat %}
+
+{% tab 'Scala 2 and 3' for=tuple-foreach-patmat %}
 ```scala mdoc
 val planets =
   List(("Mercury", 57.9), ("Venus", 108.2), ("Earth", 149.6),
        ("Mars", 227.9), ("Jupiter", 778.3))
-planets.foreach{
+planets.foreach {
   case ("Earth", distance) =>
     println(s"Our planet is $distance million kilometers from the sun")
   case _ =>
 }
 ```
+{% endtab %}
+
+{% endtabs %}
 
-Or, in `for` comprehension:
+Or, in a `for` comprehension:
 
+{% tabs tuple-for-extraction class=tabs-scala-version %}
+
+{% tab 'Scala 2' for=tuple-for-extraction %}
 ```scala mdoc
 val numPairs = List((2, 5), (3, -7), (20, 56))
 for ((a, b) <- numPairs) {
   println(a * b)
 }
 ```
+{% endtab %}
+
+{% tab 'Scala 3' for=tuple-for-extraction %}
+```scala
+val numPairs = List((2, 5), (3, -7), (20, 56))
+for (a, b) <- numPairs do
+  println(a * b)
+```
+{% endtab %}
+
+{% endtabs %}
 
 ## Tuples and case classes