Index: pkg/front_end/lib/src/scanner/reader.dart |
diff --git a/pkg/front_end/lib/src/scanner/reader.dart b/pkg/front_end/lib/src/scanner/reader.dart |
new file mode 100644 |
index 0000000000000000000000000000000000000000..9684a9c7388e3da5e8623b461829221befc5431b |
--- /dev/null |
+++ b/pkg/front_end/lib/src/scanner/reader.dart |
@@ -0,0 +1,46 @@ |
+// 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. |
+ |
+library front_end.src.scanner.reader; |
+ |
+/** |
+ * An object used by the scanner to read the characters to be scanned. |
+ */ |
+abstract class CharacterReader { |
Brian Wilkerson
2016/11/08 20:53:23
Seems odd to not have a concrete implementation in
Paul Berry
2016/11/08 21:47:06
Acknowledged. Concrete implementations will be mo
|
+ /** |
+ * The current offset relative to the beginning of the source. Return the |
+ * initial offset if the scanner has not yet scanned the source code, and one |
+ * (1) past the end of the source code if the entire source code has been |
+ * scanned. |
+ */ |
+ int get offset; |
+ |
+ /** |
+ * Set the current offset relative to the beginning of the source to the given |
+ * [offset]. The new offset must be between the initial offset and one (1) |
+ * past the end of the source code. |
+ */ |
+ void set offset(int offset); |
+ |
+ /** |
+ * Advance the current position and return the character at the new current |
+ * position. |
+ */ |
+ int advance(); |
+ |
+ /** |
+ * Return the substring of the source code between the [start] offset and the |
+ * modified current position. The current position is modified by adding the |
+ * [endDelta], which is the number of characters after the current location to |
+ * be included in the string, or the number of characters before the current |
+ * location to be excluded if the offset is negative. |
+ */ |
+ String getString(int start, int endDelta); |
+ |
+ /** |
+ * Return the character at the current position without changing the current |
+ * position. |
+ */ |
+ int peek(); |
+} |