Delete a bunch of packages that are now on GitHub.

pkg/source_span/lib/src/span_exception.dart

Index: pkg/source_span/lib/src/span_exception.dart
diff --git a/pkg/source_span/lib/src/span_exception.dart b/pkg/source_span/lib/src/span_exception.dart
deleted file mode 100644
index 36f2488329d1331589ab9dc3f1635e7ba81a7cd4..0000000000000000000000000000000000000000
--- a/pkg/source_span/lib/src/span_exception.dart
+++ /dev/null
@@ -1,43 +0,0 @@
-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library source_span.span_exception;
-
-import 'span.dart';
-
-/// A class for exceptions that have source span information attached.
-class SourceSpanException implements Exception {
-  /// A message describing the exception.
-  final String message;
-
-  /// The span associated with this exception.
-  ///
-  /// This may be `null` if the source location can't be determined.
-  final SourceSpan span;
-
-  SourceSpanException(this.message, this.span);
-
-  /// Returns a string representation of [this].
-  ///
-  /// [color] may either be a [String], a [bool], or `null`. If it's a string,
-  /// it indicates an ANSII terminal color escape that should be used to
-  /// highlight the span's text. If it's `true`, it indicates that the text
-  /// should be highlighted using the default color. If it's `false` or `null`,
-  /// it indicates that the text shouldn't be highlighted.
-  String toString({color}) {
-    if (span == null) return message;
-    return "Error on " + span.message(message, color: color);
-  }
-}
-
-/// A [SourceSpanException] that's also a [FormatException].
-class SourceSpanFormatException extends SourceSpanException
-    implements FormatException {
-  final source;
-
-  int get offset => span == null ? null : span.start.offset;
-
-  SourceSpanFormatException(String message, SourceSpan span, [this.source])
-      : super(message, span);
-}