fix typos in Spans.scala comments

Author: rethab

compiler/src/dotty/tools/dotc/reporting/Message.scala

@@ -24,9 +24,9 @@ object Message {
   * consumed by a subclass of `Reporter`. However, the error position is only
   * part of `Diagnostic`, not `Message`.
   *
-  * NOTE: you should not be persisting  Most messages take an implicit
-  * `Context` and these contexts weigh in at about 4mb per instance, as such
-  * persisting these will result in a memory leak.
+  * NOTE: you should not persist a message directly, because most messages take
+  * an implicit `Context` and these contexts weigh in at about 4mb per instance.
+  * Therefore, persisting these will result in a memory leak.
   *
   * Instead use the `persist` method to create an instance that does not keep a
   * reference to these contexts.

compiler/src/dotty/tools/dotc/util/Spans.scala

@@ -5,9 +5,9 @@ import language.implicitConversions
 /** The offsets part of a full position, consisting of 2 or 3 entries:
  *    - start:  the start offset of the span, in characters from start of file
  *    - end  :  the end offset of the span
- *    - point:  if given, the offset where a sing;le `^` would be logically placed
+ *    - point:  if given, the offset where a single `^` would be logically placed
  *
- &  Spans are encoded according to the following format in little endian:
+ *  Spans are encoded according to the following format in little endian:
  *  Start: unsigned 26 Bits (works for source files up to 64M)
  *  End: unsigned 26 Bits
  *  Point: unsigned 12 Bits relative to start
@@ -30,8 +30,8 @@ object Spans {
 
   /** A span indicates a range between a start offset and an end offset.
    *  Spans can be synthetic or source-derived. A source-derived span
-   *  has in addition a point lies somewhere between start and end. The point
-   *  is roughly where the ^ would go if an error was diagnosed at that position.
+   *  has in addition a point. The point lies somewhere between start and end. The point
+   *  is roughly where the `^` would go if an error was diagnosed at that position.
    *  All quantities are encoded opaquely in a Long.
    */
   class Span(val coords: Long) extends AnyVal {