Template parser

utils/template/token.dart

+// 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.
+
+/**
+ * A single token in the Dart language.
+ */
+class Token {
+  /** A member of [TokenKind] specifying what kind of token this is. */
+  final int kind;
+
+  /** The [SourceFile] this token came from. */
+  final SourceFile source;
+
+  /** The start and end indexes into the [SourceFile] of this [Token]. */
+  final int start, end;
+
+  Token(this.kind, this.source, this.start, this.end) {}
+
+  Token.fake(this.kind, span)
+    : this.source = span.file, this.start = span.start, this.end = span.end;
+
+  /** Returns the source text corresponding to this [Token]. */
+  String get text() {
+    return source.text.substring(start, end);
+  }
+
+  /** Returns a pretty representation of this token for error messages. **/
+  String toString() {
+    var kindText = TokenKind.kindToString(kind);
+    var actualText = text;
+    if (kindText != actualText) {
+      if (actualText.length > 10) {
+        actualText = actualText.substring(0, 8) + '...';
+      }
+      return '$kindText($actualText)';
+    } else {
+      return kindText;
+    }
+  }
+
+  /** Returns a [SourceSpan] representing the source location. */
+  SourceSpan get span() {
+    return new SourceSpan(source, start, end);
+  }
+}
+
+/** A token containing a parsed literal value. */
+class LiteralToken extends Token {
+  var value;
+  LiteralToken(kind, source, start, end, this.value)
+      : super(kind, source, start, end);
+}
+
+/** A token containing error information. */
+class ErrorToken extends Token {
+  String message;
+  ErrorToken(kind, source, start, end, this.message)
+      : super(kind, source, start, end);
+}