- Initial commit for deterministic number lexing

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/DefaultCharGetter.java

@@ -0,0 +1,103 @@
+/*******************************************************************************
+ * Copyright (c) 2012 Richard Eames
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Richard Eames - Initial implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.core.parser.scanner;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
+
+import org.eclipse.cdt.core.parser.IToken;
+import org.eclipse.cdt.internal.core.parser.scanner.NumberParser.CharGetter;
+
+public class DefaultCharGetter implements CharGetter {
+
+	private AbstractCharArray fImage;
+	private int fOffset;
+	private int fChar;
+	private Deque<Integer> fMarkOffset;
+
+	public DefaultCharGetter(char[] image, int start) {
+		this(new CharArray(image), start);
+	}
+
+	DefaultCharGetter(AbstractCharArray image, int start) {
+		fImage = image;
+		fOffset = start;
+		fChar = (fImage.tryGetLength() > 0) ? fImage.get(0) : -1;
+		fMarkOffset = new ArrayDeque<Integer>();
+	}
+
+	@Override
+	public int get() {
+		return fChar;
+	}
+
+	@Override
+	public int next() {
+		if (fImage.isValidOffset(fOffset + 1)) {
+			fChar = fImage.get(++fOffset);
+		}
+		else {
+			fChar = -1;
+		}
+		return fChar;
+	}
+
+	@Override
+	public Token getIdentifier() {
+		// Assume that the end of the number to the end of the string
+		// is an identifier
+		char[] image = new char[fImage.getLength() - fOffset];
+		fImage.arraycopy(fOffset, image, 0, image.length);
+		return new TokenWithImage(IToken.tIDENTIFIER, this, fOffset, fImage.getLength(), image);
+	}
+
+	@Override
+	public void mark() {
+		fMarkOffset.push(fOffset);
+	}
+
+	@Override
+	public void restore() {
+		fOffset = fMarkOffset.pop();
+	}
+
+	@Override
+	public int getOffset() {
+		return fOffset;
+	}
+
+	@Override
+	public char[] getSubstring(int start, int length) {
+		char [] result = new char[length];
+		fImage.arraycopy(start, result, 0, length);
+		return result;
+	}
+
+	@Override
+	public boolean isIdentifierStart() {
+		int c = get();
+		return Character.isLetter(c) || c == '_'; // Naive check
+	}
+
+	@Override
+	public char[] getCharImage(int offset, int endOffset, int imageLength) {
+		char[] result = new char[imageLength];
+		int j = 0;
+		for (int i = offset; i < endOffset; i++) {
+			char c = fImage.get(i);
+			if (c != '\n' && c != '\r') {
+				result[j++] = c;
+			}
+		}
+		return result;
+	}
+
+}