Add code tabs for _tour/operators

Author: flomebul

_tour/operators.md

@@ -11,17 +11,30 @@ prerequisite-knowledge: case-classes
 redirect_from: "/tutorials/tour/operators.html"
 ---
 In Scala, operators are methods. Any method with a single parameter can be used as an _infix operator_. For example, `+` can be called with dot-notation:
+
+{% tabs operators_1 %}
+{% tab 'Scala 2 and 3' for=operators_1 %}
 ```
 10.+(1)
 ```
+{% endtab %}
+{% endtabs %}
 
 However, it's easier to read as an infix operator:
+
+{% tabs operators_2 %}
+{% tab 'Scala 2 and 3' for=operators_2 %}
 ```
 10 + 1
 ```
+{% endtab %}
+{% endtabs %}
 
 ## Defining and using operators
 You can use any legal identifier as an operator. This includes a name like `add` or a symbol(s) like `+`.
+
+{% tabs operators_3 class=tabs-scala-version %}
+{% tab 'Scala 2' for=operators_3 %}
 ```scala mdoc
 case class Vec(x: Double, y: Double) {
   def +(that: Vec) = Vec(this.x + that.x, this.y + that.y)
@@ -34,27 +47,62 @@ val vector3 = vector1 + vector2
 vector3.x  // 3.0
 vector3.y  // 3.0
 ```
+{% endtab %}
+{% tab 'Scala 3' for=operators_3 %}
+```scala
+case class Vec(x: Double, y: Double):
+  def +(that: Vec) = Vec(this.x + that.x, this.y + that.y)
+
+val vector1 = Vec(1.0, 1.0)
+val vector2 = Vec(2.0, 2.0)
+
+val vector3 = vector1 + vector2
+vector3.x  // 3.0
+vector3.y  // 3.0
+```
+{% endtab %}
+{% endtabs %}
+
 The class Vec has a method `+` which we used to add `vector1` and `vector2`. Using parentheses, you can build up complex expressions with readable syntax. Here is the definition of class `MyBool` which includes methods `and` and `or`:
 
+{% tabs operators_4 class=tabs-scala-version %}
+{% tab 'Scala 2' for=operators_4 %}
 ```scala mdoc
 case class MyBool(x: Boolean) {
   def and(that: MyBool): MyBool = if (x) that else this
   def or(that: MyBool): MyBool = if (x) this else that
   def negate: MyBool = MyBool(!x)
 }
 ```
+{% endtab %}
+{% tab 'Scala 3' for=operators_4 %}
+```scala
+case class MyBool(x: Boolean):
+  def and(that: MyBool): MyBool = if x then that else this
+  def or(that: MyBool): MyBool = if x then this else that
+  def negate: MyBool = MyBool(!x)
+```
+{% endtab %}
+{% endtabs %}
 
 It is now possible to use `and` and `or` as infix operators:
 
+{% tabs operators_5 %}
+{% tab 'Scala 2 and 3' for=operators_5 %}
 ```scala mdoc
 def not(x: MyBool) = x.negate
 def xor(x: MyBool, y: MyBool) = (x or y) and not(x and y)
 ```
+{% endtab %}
+{% endtabs %}
 
 This helps to make the definition of `xor` more readable.
 
 ## Precedence
 When an expression uses multiple operators, the operators are evaluated based on the priority of the first character:
+
+{% tabs operators_6 %}
+{% tab 'Scala 2 and 3' for=operators_6 %}
 ```
 (characters not shown below)
 * / %
@@ -67,12 +115,27 @@ When an expression uses multiple operators, the operators are evaluated based on
 |
 (all letters, $, _)
 ```
+{% endtab %}
+{% endtabs %}
+
 This applies to functions you define. For example, the following expression:
+
+{% tabs operators_7 %}
+{% tab 'Scala 2 and 3' for=operators_7 %}
 ```
 a + b ^? c ?^ d less a ==> b | c
 ```
+{% endtab %}
+{% endtabs %}
+
 Is equivalent to
+
+{% tabs operators_8 %}
+{% tab 'Scala 2 and 3' for=operators_8 %}
 ```
 ((a + b) ^? (c ?^ d)) less ((a ==> b) | c)
 ```
+{% endtab %}
+{% endtabs %}
+
 `?^` has the highest precedence because it starts with the character `?`. `+` has the second highest precedence, followed by `==>`, `^?`, `|`, and `less`.