Template parser

utils/css/source.dart

Index: utils/css/source.dart
diff --git a/utils/css/source.dart b/utils/css/source.dart
new file mode 100644
index 0000000000000000000000000000000000000000..38be4a687f0222e0629dbdef6cb45ab28c0c3398
--- /dev/null
+++ b/utils/css/source.dart
@@ -0,0 +1,186 @@
+// Copyright (c) 2011, 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.
+
+// TODO(jimhug): This should be an interface to work better with tools.
+/**
+ * Represents a file of source code.
+ */
+class SourceFile implements Comparable {
+  // TODO(terry): This filename for in memory buffer.  May need to rework if
+  //              filename is used for more than informational.
+  static String IN_MEMORY_FILE = '<buffer>';
+
+  /** The name of the file. */
+  final String filename;
+
+  /** The text content of the file. */
+  String _text;
+
+  /**
+   * The order of the source file in a given library. This is used while we're
+   * writing code for a library. A single source file can be used
+   */
+  // TODO(jmesserly): I don't like having properties that are only valid
+  // sometimes. An alternative would be to store it in a Map that's used by
+  // WorldGenerator while it's emitting code. This seems simpler.
+  int orderInLibrary;
+
+  List<int> _lineStarts;
+
+  SourceFile(this.filename, this._text);
+
+  String get text() => _text;
+
+  set text(String newText) {
+    if (newText != _text) {
+      _text = newText;
+      _lineStarts = null;
+      orderInLibrary = null;
+    }
+  }
+
+  List<int> get lineStarts() {
+    if (_lineStarts == null) {
+      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);
+      _lineStarts = starts;
+    }
+    return _lineStarts;
+  }
+
+  int getLine(int position) {
+    // TODO(jimhug): Implement as binary search.
+    var starts = lineStarts;
+    for (int i=0; i < starts.length; i++) {
+      if (starts[i] > position) return i-1;
+    }
+    world.internalError('bad position');
+  }
+
+  int getColumn(int line, int position) {
+    return position - lineStarts[line];
+  }
+
+  /**
+   * Create a pretty string representation from a character position
+   * in the file.
+   */
+  String getLocationMessage(String message, int start,
+      [int end, bool includeText=false]) {
+    var line = getLine(start);
+    var column = getColumn(line, start);
+
+    var buf = new StringBuffer(
+        '${filename}:${line + 1}:${column + 1}: $message');
+    if (includeText) {
+      buf.add('\n');
+      var textLine;
+      // +1 for 0-indexing, +1 again to avoid the last line of the file
+      if ((line + 2) < _lineStarts.length) {
+        textLine = text.substring(_lineStarts[line], _lineStarts[line+1]);
+      } else {
+        textLine = text.substring(_lineStarts[line]) + '\n';
+      }
+
+      int toColumn = Math.min(column + (end-start), textLine.length);
+      if (options.useColors) {
+        buf.add(textLine.substring(0, column));
+        buf.add(_RED_COLOR);
+        buf.add(textLine.substring(column, toColumn));
+        buf.add(_NO_COLOR);
+        buf.add(textLine.substring(toColumn));
+      } else {
+        buf.add(textLine);
+      }
+
+      int i = 0;
+      for (; i < column; i++) {
+        buf.add(' ');
+      }
+
+      if (options.useColors) buf.add(_RED_COLOR);
+      for (; i < toColumn; i++) {
+        buf.add('^');
+      }
+      if (options.useColors) buf.add(_NO_COLOR);
+    }
+
+    return buf.toString();
+  }
+
+  /** Compares two source files. */
+  int compareTo(SourceFile other) {
+    if (orderInLibrary != null && other.orderInLibrary != null) {
+      return orderInLibrary - other.orderInLibrary;
+    } else {
+      return filename.compareTo(other.filename);
+    }
+  }
+}
+
+
+/**
+ * A range of characters in a [SourceFile].  Used to represent the source
+ * positions of [Token]s and [Node]s for error reporting or other tooling
+ * work.
+ */
+ // TODO(jmesserly): Rename to Span - but first write cool refactoring tool
+class SourceSpan implements Comparable {
+  /** The [SourceFile] that contains this span. */
+  final SourceFile file;
+
+  /** The character position of the start of this span. */
+  final int start;
+
+  /** The character position of the end of this span. */
+  final int end;
+
+  SourceSpan(this.file, this.start, this.end);
+
+  /** Returns the source text corresponding to this [Span]. */
+  String get text() {
+    return file.text.substring(start, end);
+  }
+
+  toMessageString(String message) {
+    return file.getLocationMessage(message, start, end: end, includeText: true);
+  }
+
+  int get line() {
+    return file.getLine(start);
+  }
+
+  int get column() {
+    return file.getColumn(line, start);
+  }
+
+  int get endLine() {
+    return file.getLine(end);
+  }
+
+  int get endColumn() {
+    return file.getColumn(endLine, end);
+  }
+
+  String get locationText() {
+    var line = file.getLine(start);
+    var column = file.getColumn(line, start);
+    return '${file.filename}:${line + 1}:${column + 1}';
+  }
+
+  /** Compares two source spans by file and position. Handles nulls. */
+  int compareTo(SourceSpan other) {
+    if (file == other.file) {
+      int d = start - other.start;
+      return d == 0 ? (end - other.end) : d;
+    }
+    return file.compareTo(other.file);
+  }
+}