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| 1 // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| 2 // for details. All rights reserved. Use of this source code is governed by a |
| 3 // BSD-style license that can be found in the LICENSE file. |
| 4 |
| 5 library source_span.location; |
| 6 |
| 7 import 'span.dart'; |
| 8 |
| 9 // TODO(nweiz): Use SourceLocationMixin once we decide to cut a release with |
| 10 // breaking changes. See SourceLocationMixin for details. |
| 11 |
| 12 /// A class that describes a single location within a source file. |
| 13 /// |
| 14 /// This class should not be extended. Instead, [SourceLocationBase] should be |
| 15 /// extended instead. |
| 16 class SourceLocation implements Comparable<SourceLocation> { |
| 17 /// URL of the source containing this location. |
| 18 /// |
| 19 /// This may be null, indicating that the source URL is unknown or |
| 20 /// unavailable. |
| 21 final Uri sourceUrl; |
| 22 |
| 23 /// The 0-based offset of this location in the source. |
| 24 final int offset; |
| 25 |
| 26 /// The 0-based line of this location in the source. |
| 27 final int line; |
| 28 |
| 29 /// The 0-based column of this location in the source |
| 30 final int column; |
| 31 |
| 32 /// Returns a representation of this location in the `source:line:column` |
| 33 /// format used by text editors. |
| 34 /// |
| 35 /// This prints 1-based lines and columns. |
| 36 String get toolString { |
| 37 var source = sourceUrl == null ? 'unknown source' : sourceUrl; |
| 38 return '$source:${line + 1}:${column + 1}'; |
| 39 } |
| 40 |
| 41 /// Creates a new location indicating [offset] within [sourceUrl]. |
| 42 /// |
| 43 /// [line] and [column] default to assuming the source is a single line. This |
| 44 /// means that [line] defaults to 0 and [column] defaults to [offset]. |
| 45 /// |
| 46 /// [sourceUrl] may be either a [String], a [Uri], or `null`. |
| 47 SourceLocation(int offset, {sourceUrl, int line, int column}) |
| 48 : sourceUrl = sourceUrl is String ? Uri.parse(sourceUrl) : sourceUrl, |
| 49 offset = offset, |
| 50 line = line == null ? 0 : line, |
| 51 column = column == null ? offset : column { |
| 52 if (offset < 0) { |
| 53 throw new RangeError("Offset may not be negative, was $offset."); |
| 54 } else if (line != null && line < 0) { |
| 55 throw new RangeError("Line may not be negative, was $line."); |
| 56 } else if (column != null && column < 0) { |
| 57 throw new RangeError("Column may not be negative, was $column."); |
| 58 } |
| 59 } |
| 60 |
| 61 /// Returns the distance in characters between [this] and [other]. |
| 62 /// |
| 63 /// This always returns a non-negative value. |
| 64 int distance(SourceLocation other) { |
| 65 if (sourceUrl != other.sourceUrl) { |
| 66 throw new ArgumentError("Source URLs \"${sourceUrl}\" and " |
| 67 "\"${other.sourceUrl}\" don't match."); |
| 68 } |
| 69 return (offset - other.offset).abs(); |
| 70 } |
| 71 |
| 72 /// Returns a span that covers only a single point: this location. |
| 73 SourceSpan pointSpan() => new SourceSpan(this, this, ""); |
| 74 |
| 75 /// Compares two locations. |
| 76 /// |
| 77 /// [other] must have the same source URL as [this]. |
| 78 int compareTo(SourceLocation other) { |
| 79 if (sourceUrl != other.sourceUrl) { |
| 80 throw new ArgumentError("Source URLs \"${sourceUrl}\" and " |
| 81 "\"${other.sourceUrl}\" don't match."); |
| 82 } |
| 83 return offset - other.offset; |
| 84 } |
| 85 |
| 86 bool operator ==(other) => |
| 87 other is SourceLocation && sourceUrl == other.sourceUrl && |
| 88 offset == other.offset; |
| 89 |
| 90 int get hashCode => sourceUrl.hashCode + offset; |
| 91 |
| 92 String toString() => '<$runtimeType: $offset $toolString>'; |
| 93 } |
| 94 |
| 95 /// A base class for source locations with [offset], [line], and [column] known |
| 96 /// at construction time. |
| 97 class SourceLocationBase extends SourceLocation { |
| 98 SourceLocationBase(int offset, {sourceUrl, int line, int column}) |
| 99 : super(offset, sourceUrl: sourceUrl, line: line, column: column); |
| 100 } |
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