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source_span/lib/src/location.dart

-// 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.location;
-
-import 'span.dart';
-
-// TODO(nweiz): Use SourceLocationMixin once we decide to cut a release with
-// breaking changes. See SourceLocationMixin for details.
-
-/// A class that describes a single location within a source file.
-///
-/// This class should not be extended. Instead, [SourceLocationBase] should be
-/// extended instead.
-class SourceLocation implements Comparable<SourceLocation> {
-  /// URL of the source containing this location.
-  ///
-  /// This may be null, indicating that the source URL is unknown or
-  /// unavailable.
-  final Uri sourceUrl;
-
-  /// The 0-based offset of this location in the source.
-  final int offset;
-
-  /// The 0-based line of this location in the source.
-  final int line;
-
-  /// The 0-based column of this location in the source
-  final int column;
-
-  /// Returns a representation of this location in the `source:line:column`
-  /// format used by text editors.
-  ///
-  /// This prints 1-based lines and columns.
-  String get toolString {
-    var source = sourceUrl == null ? 'unknown source' : sourceUrl;
-    return '$source:${line + 1}:${column + 1}';
-  }
-
-  /// Creates a new location indicating [offset] within [sourceUrl].
-  ///
-  /// [line] and [column] default to assuming the source is a single line. This
-  /// means that [line] defaults to 0 and [column] defaults to [offset].
-  ///
-  /// [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 {
-    if (offset < 0) {
-      throw new RangeError("Offset may not be negative, was $offset.");
-    } else if (line != null && line < 0) {
-      throw new RangeError("Line may not be negative, was $line.");
-    } else if (column != null && column < 0) {
-      throw new RangeError("Column may not be negative, was $column.");
-    }
-  }
-
-  /// Returns the distance in characters between [this] and [other].
-  ///
-  /// This always returns a non-negative value.
-  int distance(SourceLocation other) {
-    if (sourceUrl != other.sourceUrl) {
-      throw new ArgumentError("Source URLs \"${sourceUrl}\" and "
-          "\"${other.sourceUrl}\" don't match.");
-    }
-    return (offset - other.offset).abs();
-  }
-
-  /// Returns a span that covers only a single point: this location.
-  SourceSpan pointSpan() => new SourceSpan(this, this, "");
-
-  /// Compares two locations.
-  ///
-  /// [other] must have the same source URL as [this].
-  int compareTo(SourceLocation other) {
-    if (sourceUrl != other.sourceUrl) {
-      throw new ArgumentError("Source URLs \"${sourceUrl}\" and "
-          "\"${other.sourceUrl}\" don't match.");
-    }
-    return offset - other.offset;
-  }
-
-  bool operator ==(other) =>
-      other is SourceLocation && sourceUrl == other.sourceUrl &&
-      offset == other.offset;
-
-  int get hashCode => sourceUrl.hashCode + offset;
-
-  String toString() => '<$runtimeType: $offset $toolString>';
-}
-
-/// A base class for source locations with [offset], [line], and [column] known
-/// at construction time.
-class SourceLocationBase extends SourceLocation {
-  SourceLocationBase(int offset, {sourceUrl, int line, int column})
-      : super(offset, sourceUrl: sourceUrl, line: line, column: column);
-}