Emit to StreamCodeOutput instead of CodeBuffer.

pkg/compiler/lib/src/source_file.dart

-// Copyright (c) 2012, 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_file;
-
-import 'dart:math';
-import 'dart:convert' show UTF8;
-
-/// Interface for providing line/column information.
-abstract class LineColumnProvider {
-  /// Returns the line number (0-based) for [offset].
-  int getLine(int offset);
-
-  /// Returns the column number (0-based) for [offset] at the given [line].
-  int getColumn(int line, int offset);
-}
-
-/**
- * Represents a file of source code. The content can be either a [String] or
- * a UTF-8 encoded [List<int>] of bytes.
- */
-abstract class SourceFile implements LineColumnProvider {
-
-  /** The name of the file. */
-  String get filename;
-
-  /** The text content of the file represented as a String. */
-  String slowText();
-
-  /** The content of the file represented as a UTF-8 encoded [List<int>]. */
-  List<int> slowUtf8Bytes();
-
-  /**
-   * The length of the string representation of this source file, i.e.,
-   * equivalent to [:slowText().length:], but faster.
-   */
-  int get length;
-
-  /**
-   * Sets the string length of this source file. For source files based on UTF-8
-   * byte arrays, the string length is computed and assigned by the scanner.
-   */
-  set length(int v);
-
-  /**
-   * A map from line numbers to offsets in the string text representation of
-   * this source file.
-   */
-  List<int> get lineStarts {
-    if (lineStartsCache == null) {
-      // When reporting errors during scanning, the line numbers are not yet
-      // available and need to be computed using this slow path.
-      lineStartsCache = lineStartsFromString(slowText());
-    }
-    return lineStartsCache;
-  }
-
-  /**
-   * Sets the line numbers map for this source file. This map is computed and
-   * assigned by the scanner, avoiding a separate traversal of the source file.
-   *
-   * The map contains one additional entry at the end of the file, as if the
-   * source file had one more empty line at the end. This simplifies the binary
-   * search in [getLine].
-   */
-  set lineStarts(List<int> v) => lineStartsCache = v;
-
-  List<int> lineStartsCache;
-
-  List<int> lineStartsFromString(String text) {
-    var starts = [0];
-    var index = 0;
-    while (index < text.length) {
-      index = text.indexOf('\n', index) + 1;
-      if (index <= 0) break;
-      starts.add(index);
-    }
-    starts.add(text.length + 1); // One additional line start at the end.
-    return starts;
-  }
-
-  /**
-   * Returns the line number for the offset [position] in the string
-   * representation of this source file.
-   */
-  int getLine(int position) {
-    List<int> starts = lineStarts;
-    if (position < 0 || starts.last <= position) {
-      throw 'bad position #$position in file $filename with '
-            'length ${length}.';
-    }
-    int first = 0;
-    int count = starts.length;
-    while (count > 1) {
-      int step = count ~/ 2;
-      int middle = first + step;
-      int lineStart = starts[middle];
-      if (position < lineStart) {
-        count = step;
-      } else {
-        first = middle;
-        count -= step;
-      }
-    }
-    return first;
-  }
-
-  /**
-   * Returns the column number for the offset [position] in the string
-   * representation of this source file.
-   */
-  int getColumn(int line, int position) {
-    return position - lineStarts[line];
-  }
-
-  String slowSubstring(int start, int end);
-
-  /**
-   * Create a pretty string representation for [message] from a character
-   * range `[start, end]` in this file.
-   *
-   * If [includeSourceLine] is `true` the first source line code line that
-   * contains the range will be included as well as marker characters ('^')
-   * underlining the range.
-   *
-   * Use [colorize] to wrap source code text and marker characters in color
-   * escape codes.
-   */
-  String getLocationMessage(String message, int start, int end,
-                            {bool includeSourceLine: true,
-                             String colorize(String text)}) {
-    if (colorize == null) {
-      colorize = (text) => text;
-    }
-    var line = getLine(start);
-    var column = getColumn(line, start);
-
-    var buf = new StringBuffer('${filename}:');
-    if (start != end || start != 0) {
-      // Line/column info is relevant.
-      buf.write('${line + 1}:${column + 1}:');
-    }
-    buf.write('\n$message\n');
-
-    if (start != end && includeSourceLine) {
-      String textLine;
-      // +1 for 0-indexing, +1 again to avoid the last line of the file
-      if ((line + 2) < lineStarts.length) {
-        textLine = slowSubstring(lineStarts[line], lineStarts[line+1]);
-      } else {
-        textLine = '${slowSubstring(lineStarts[line], length)}\n';
-      }
-
-      int toColumn = min(column + (end-start), textLine.length);
-      buf.write(textLine.substring(0, column));
-      buf.write(colorize(textLine.substring(column, toColumn)));
-      buf.write(textLine.substring(toColumn));
-
-      int i = 0;
-      for (; i < column; i++) {
-        buf.write(' ');
-      }
-
-      for (; i < toColumn; i++) {
-        buf.write(colorize('^'));
-      }
-    }
-
-    return buf.toString();
-  }
-}
-
-class Utf8BytesSourceFile extends SourceFile {
-  final String filename;
-
-  /** The UTF-8 encoded content of the source file. */
-  final List<int> content;
-
-  Utf8BytesSourceFile(this.filename, this.content);
-
-  String slowText() => UTF8.decode(content);
-
-  List<int> slowUtf8Bytes() => content;
-
-  String slowSubstring(int start, int end) {
-    // TODO(lry): to make this faster, the scanner could record the UTF-8 slack
-    // for all positions of the source text. We could use [:content.sublist:].
-    return slowText().substring(start, end);
-  }
-
-  int get length {
-    if (lengthCache == -1) {
-      // During scanning the length is not yet assigned, so we use a slow path.
-      length = slowText().length;
-    }
-    return lengthCache;
-  }
-  set length(int v) => lengthCache = v;
-  int lengthCache = -1;
-}
-
-class CachingUtf8BytesSourceFile extends Utf8BytesSourceFile {
-  String cachedText;
-
-  CachingUtf8BytesSourceFile(String filename, List<int> content)
-      : super(filename, content);
-
-  String slowText() {
-    if (cachedText == null) {
-      cachedText = super.slowText();
-    }
-    return cachedText;
-  }
-}
-
-class StringSourceFile extends SourceFile {
-  final String filename;
-  final String text;
-
-  StringSourceFile(this.filename, this.text);
-
-  int get length => text.length;
-  set length(int v) { }
-
-  String slowText() => text;
-
-  List<int> slowUtf8Bytes() => UTF8.encode(text);
-
-  String slowSubstring(int start, int end) => text.substring(start, end);
-}