Allow some fields to be overridden in strong mode.

lib/src/location.dart

Index: lib/src/location.dart
diff --git a/lib/src/location.dart b/lib/src/location.dart
index 2d23db1a3d7b67cb6d0146c285a6ef245ce71bef..0dbf44c2806dd90653f5b62c1b272ee99631dc2a 100644
--- a/lib/src/location.dart
+++ b/lib/src/location.dart
@@ -12,20 +12,27 @@ import 'span.dart';
 /// This class should not be extended. Instead, [SourceLocationBase] should be
 /// extended instead.
 class SourceLocation implements Comparable<SourceLocation> {
+  // These fields go through getters so that subclasses of [SourceLocationBase]
+  // can override them.
+
   /// URL of the source containing this location.
   ///
   /// This may be null, indicating that the source URL is unknown or
   /// unavailable.
-  final Uri sourceUrl;
+  Uri get sourceUrl => _sourceUrl;
+  final Uri _sourceUrl;

[Lasse Reichstein Nielsen, 2016/03/01 15:22:42]

What does this change?

A field already introduces an implicit getter, so the external interface of the
class is unchanged by this modification.

Is it to allow subclasses inside the same package to overide the implicit
_sourceUrl getter?

The changelog text mentions strong mode. Does strong mode differentiate between
an implicit and an explicit getter? If so, it should be fixed.

[nweiz, 2016/03/01 19:16:09]

Yes, it does. I'll forward you the email thread where we discussed it.

 
   /// The 0-based offset of this location in the source.
-  final int offset;
+  int get offset => _offset;
+  final int _offset;
 
   /// The 0-based line of this location in the source.
-  final int line;
+  int get line => _line;
+  final int _line;
 
   /// The 0-based column of this location in the source
-  final int column;
+  int get column => _column;
+  final int _column;
 
   /// Returns a representation of this location in the `source:line:column`
   /// format used by text editors.
@@ -43,10 +50,10 @@ class SourceLocation implements Comparable<SourceLocation> {
   ///
   /// [sourceUrl] may be either a [String], a [Uri], or `null`.
   SourceLocation(int offset, {sourceUrl, int line, int column})
-      : sourceUrl = sourceUrl is String ? Uri.parse(sourceUrl) : sourceUrl,
-        offset = offset,
-        line = line == null ? 0 : line,
-        column = column == null ? offset : column {
+      : _sourceUrl = sourceUrl is String ? Uri.parse(sourceUrl) : sourceUrl,
+        _offset = offset,
+        _line = line == null ? 0 : line,
+        _column = column == null ? offset : column {
     if (offset < 0) {
       throw new RangeError("Offset may not be negative, was $offset.");
     } else if (line != null && line < 0) {