| // 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. |
| |
| import 'location.dart'; |
| import 'span_mixin.dart'; |
| |
| /// A class that describes a segment of source text. |
| abstract class SourceSpan implements Comparable<SourceSpan> { |
| /// The start location of this span. |
| final SourceLocation start; |
| |
| /// The end location of this span, exclusive. |
| final SourceLocation end; |
| |
| /// The source text for this span. |
| final String text; |
| |
| /// The URL of the source (typically a file) of this span. |
| /// |
| /// This may be null, indicating that the source URL is unknown or |
| /// unavailable. |
| final Uri sourceUrl; |
| |
| /// The length of this span, in characters. |
| final int length; |
| |
| /// Creates a new span from [start] to [end] (exclusive) containing [text]. |
| /// |
| /// [start] and [end] must have the same source URL and [start] must come |
| /// before [end]. [text] must have a number of characters equal to the |
| /// distance between [start] and [end]. |
| factory SourceSpan(SourceLocation start, SourceLocation end, String text) => |
| new SourceSpanBase(start, end, text); |
| |
| /// Creates a new span that's the union of [this] and [other]. |
| /// |
| /// The two spans must have the same source URL and may not be disjoint. |
| /// [text] is computed by combining [this.text] and [other.text]. |
| SourceSpan union(SourceSpan other); |
| |
| /// Compares two spans. |
| /// |
| /// [other] must have the same source URL as [this]. This orders spans by |
| /// [start] then [length]. |
| int compareTo(SourceSpan other); |
| |
| /// Formats [message] in a human-friendly way associated with this span. |
| /// |
| /// [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 message(String message, {color}); |
| |
| /// Prints the text associated with this span in a user-friendly way. |
| /// |
| /// This is identical to [message], except that it doesn't print the file |
| /// name, line number, column number, or message. If [length] is 0 and this |
| /// isn't a [SourceSpanWithContext], returns an empty string. |
| /// |
| /// [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 highlight({color}); |
| } |
| |
| /// A base class for source spans with [start], [end], and [text] known at |
| /// construction time. |
| class SourceSpanBase extends SourceSpanMixin { |
| final SourceLocation start; |
| final SourceLocation end; |
| final String text; |
| |
| SourceSpanBase(this.start, this.end, this.text) { |
| if (end.sourceUrl != start.sourceUrl) { |
| throw new ArgumentError("Source URLs \"${start.sourceUrl}\" and " |
| " \"${end.sourceUrl}\" don't match."); |
| } else if (end.offset < start.offset) { |
| throw new ArgumentError('End $end must come after start $start.'); |
| } else if (text.length != start.distance(end)) { |
| throw new ArgumentError('Text "$text" must be ${start.distance(end)} ' |
| 'characters long.'); |
| } |
| } |
| } |