| /* |
| * Copyright (c) 2013, the Dart project authors. |
| * |
| * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except |
| * in compliance with the License. You may obtain a copy of the License at |
| * |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Unless required by applicable law or agreed to in writing, software distributed under the License |
| * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express |
| * or implied. See the License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| package com.google.dart.engine.scanner; |
| |
| /** |
| * The interface {@code CharacterReader} |
| */ |
| public interface CharacterReader { |
| /** |
| * Advance the current position and return the character at the new current position. |
| * |
| * @return the character at the new current position |
| */ |
| public int advance(); |
| |
| /** |
| * Return 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. |
| * |
| * @return the current offset of the scanner in the source |
| */ |
| public int getOffset(); |
| |
| /** |
| * Return the substring of the source code between the start offset and the modified current |
| * position. The current position is modified by adding the end delta. |
| * |
| * @param start the offset to the beginning of the string, relative to the start of the file |
| * @param endDelta 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 |
| * @return the specified substring of the source code |
| */ |
| public String getString(int start, int endDelta); |
| |
| /** |
| * Return the character at the current position without changing the current position. |
| * |
| * @return the character at the current position |
| */ |
| public int peek(); |
| |
| /** |
| * Set the current offset relative to the beginning of the source. The new offset must be between |
| * the initial offset and one (1) past the end of the source code. |
| * |
| * @param offset the new offset in the source |
| */ |
| public void setOffset(int offset); |
| } |