Introduce concepts of list head/tail before use (#188)

JacobArchambault · web-flow · commit 27fe05b605d2 · 2020-11-25T19:23:20.000+01:00
The concepts of the head and tail of a list are used at line 100 without first being introduced. This change introduces the concepts earlier by making a minor addition at the introductory discussion of the constructor ::.
diff --git a/src/main/scala/scalatutorial/sections/StandardLibrary.scala b/src/main/scala/scalatutorial/sections/StandardLibrary.scala
@@ -61,7 +61,7 @@ object StandardLibrary extends ScalaTutorialSection {
    *
    *  - the empty list `Nil`, and
    *  - the construction operation `::` (pronounced ''cons''): `x :: xs` gives a new list
-   *    with the first element `x`, followed by the elements of `xs` (which is a list itself).
+   *    with the first element `x`, called the `head`, followed by the `tail` `xs`, which is itself a list of elements.
    *
    * For example:
    *

Original file line number	Diff line number	Diff line change
`@@ -61,7 +61,7 @@ object StandardLibrary extends ScalaTutorialSection {`
`61`	`61`	`*`
`62`	`62`	* - the empty list `Nil`, and
`63`	`63`	* - the construction operation `::` (pronounced ''cons''): `x :: xs` gives a new list
`64`		- * with the first element `x`, followed by the elements of `xs` (which is a list itself).
	`64`	+ * with the first element `x`, called the `head`, followed by the `tail` `xs`, which is itself a list of elements.
`65`	`65`	`*`
`66`	`66`	`* For example:`
`67`	`67`	`*`