github markdown: code blocks

1 files changed, 12 insertions, 12 deletions

diff --git a/13-user-defined-annotations.md b/13-user-defined-annotations.md
index 1aa5e7e613..717a6dcb1f 100644
--- a/13-user-defined-annotations.md
+++ b/13-user-defined-annotations.md
@@ -1,9 +1,9 @@
 # User-Defined Annotations
 
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
+``` 
   Annotation       ::=  ‘@’ SimpleType {ArgumentExprs}
   ConstrAnnotation ::=  ‘@’ SimpleType ArgumentExprs
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+```
 
 User-defined annotations associate meta-information with definitions.
 A simple annotation has the form `@$c$` or `@$c(a_1 , \ldots , a_n)$`.
@@ -20,12 +20,12 @@ does not matter.
 
 Examples:
 
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
+``` 
 @serializable class C { ... }         // A class annotation.
 @transient @volatile var m: Int       // A variable annotation
 String @local                         // A type annotation
 (e: @unchecked) match { ... }         // An expression annotation
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+```
 
 The meaning of annotation clauses is implementation-dependent. On the
 Java platform, the following annotations have a standard meaning.
@@ -55,9 +55,9 @@ Java platform, the following annotations have a standard meaning.
 	This is equivalent to a the following field
 	definition in Java:
 
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
+	``` 
 	private final static SerialVersionUID = <longlit> 
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+	```
 
   * `@throws(<classlit>)` \
 	A Java compiler checks that a program contains handlers for checked exceptions
@@ -95,11 +95,11 @@ Java platform, the following annotations have a standard meaning.
 	matches which would otherwise be emitted. For instance, no warnings
 	would be produced for the method definition below.
 
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
+	``` 
 	def f(x: Option[Int]) = (x: @unchecked) match {
 	  case Some(y) => y
 	}
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+	```
 
 	Without the `@unchecked` annotation, a Scala compiler could
 	infer that the pattern match is non-exhaustive, and could produce a
@@ -110,12 +110,12 @@ Java platform, the following annotations have a standard meaning.
 	value to appear in a path, even if its type is [volatile](#volatile-types).
 	For instance, the following member definitions are legal:
 
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
+	``` 
 	type A { type T }
 	type B 
 	@uncheckedStable val x: A with B // volatile type 
 	val y: x.T                       // OK since `x' is still a path
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+	```
 
 	Without the `@uncheckedStable` annotation, the designator `x`
 	would not be a path since its type `A with B` is volatile. Hence,
@@ -135,11 +135,11 @@ Java platform, the following annotations have a standard meaning.
 	For instance, the following code would generate specialized traits for
 	`Unit`, `Int` and `Double`
 
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
+	``` 
 	trait Function0[@specialized(Unit, Int, Double) T] {
 	  def apply: T
 	}
-	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+	```
 
 	Whenever the static type of an expression matches a specialized variant of 
 	a definition,