Inlined the code examples in the unbound placeholder explanation.

Author: rubenpieters

src/dotty/tools/dotc/reporting/diagnostic/messages.scala

@@ -407,26 +407,6 @@ object messages {
 
     val msg = hl"unbound placeholder parameter; incorrect use of `_`"
 
-    val codeUnboundInBlock =
-      """
-        |{ _ }
-      """.stripMargin
-
-    val codeBoundInBlock =
-      """
-        |x => { x }
-      """.stripMargin
-
-    val codeUnboundVal =
-      """
-        |val a = _
-      """.stripMargin
-
-    val codeVar =
-      """
-        |var a = _
-      """.stripMargin
-
     val explanation =
       hl"""The `_` placeholder syntax was used where it could not be bound.
         |Consider explicitly writing the variable binding.
@@ -436,21 +416,21 @@ object messages {
         |
         |Example before:
         |
-        |$codeUnboundInBlock
+        |${"{ _ }"}
         |
         |Example after:
         |
-        |$codeBoundInBlock
+        |${"x => { x }"}
         |
         |Another common occurrence for this error is defining a val with `_`:
         |
-        |$codeUnboundVal
+        |${"val a = _"}
         |
         |But this val definition isn't very useful, it can never be assigned
         |another value. And thus will always remain uninitialized.
         |Consider replacing the ${"val"} with ${"var"}:
         |
-        |$codeVar
+        |${"var a = _"}
         |
         |Note that this use of `_` is not placeholder syntax,
         |but an uninitialized var definition