few more helper methods

asm/src/org/aspectj/asm/internal/CharOperation.java

@@ -16,6 +16,10 @@ package org.aspectj.asm.internal;
  */
 public class CharOperation {
 
+	public static final char[][] NO_CHAR_CHAR = new char[0][];
+
+	public static final char[] NO_CHAR = new char[0];
+
 	/**
 	 * Taken from org.aspectj.org.eclipse.jdt.core.compiler.CharOperation
 	 */
@@ -34,6 +38,44 @@ public class CharOperation {
 		return result;
 	}
 
+	public static final char[][] subarray(char[][] array, int start, int end) {
+		if (end == -1)
+			end = array.length;
+		if (start > end)
+			return null;
+		if (start < 0)
+			return null;
+		if (end > array.length)
+			return null;
+
+		char[][] result = new char[end - start][];
+		System.arraycopy(array, start, result, 0, end - start);
+		return result;
+	}
+
+	public static final char[][] splitOn(char divider, char[] array) {
+		int length = array == null ? 0 : array.length;
+		if (length == 0)
+			return NO_CHAR_CHAR;
+
+		int wordCount = 1;
+		for (int i = 0; i < length; i++)
+			if (array[i] == divider)
+				wordCount++;
+		char[][] split = new char[wordCount][];
+		int last = 0, currentWord = 0;
+		for (int i = 0; i < length; i++) {
+			if (array[i] == divider) {
+				split[currentWord] = new char[i - last];
+				System.arraycopy(array, last, split[currentWord++], 0, i - last);
+				last = i + 1;
+			}
+		}
+		split[currentWord] = new char[length - last];
+		System.arraycopy(array, last, split[currentWord], 0, length - last);
+		return split;
+	}
+
 	/**
 	 * Taken from org.aspectj.org.eclipse.jdt.core.compiler.CharOperation
 	 */
@@ -88,6 +130,67 @@ public class CharOperation {
 		return true;
 	}
 
+	final static public String toString(char[][] array) {
+		char[] result = concatWith(array, '.');
+		return new String(result);
+	}
+
+	public static final char[] concatWith(char[][] array, char separator) {
+		int length = array == null ? 0 : array.length;
+		if (length == 0)
+			return CharOperation.NO_CHAR;
+
+		int size = length - 1;
+		int index = length;
+		while (--index >= 0) {
+			if (array[index].length == 0)
+				size--;
+			else
+				size += array[index].length;
+		}
+		if (size <= 0)
+			return CharOperation.NO_CHAR;
+		char[] result = new char[size];
+		index = length;
+		while (--index >= 0) {
+			length = array[index].length;
+			if (length > 0) {
+				System.arraycopy(array[index], 0, result, (size -= length), length);
+				if (--size >= 0)
+					result[size] = separator;
+			}
+		}
+		return result;
+	}
+
+	public static final int hashCode(char[] array) {
+		int length = array.length;
+		int hash = length == 0 ? 31 : array[0];
+		if (length < 8) {
+			for (int i = length; --i > 0;)
+				hash = (hash * 31) + array[i];
+		} else {
+			// 8 characters is enough to compute a decent hash code, don't waste time examining every character
+			for (int i = length - 1, last = i > 16 ? i - 16 : 0; i > last; i -= 2)
+				hash = (hash * 31) + array[i];
+		}
+		return hash & 0x7FFFFFFF;
+	}
+
+	public static final boolean equals(char[][] first, char[][] second) {
+		if (first == second)
+			return true;
+		if (first == null || second == null)
+			return false;
+		if (first.length != second.length)
+			return false;
+
+		for (int i = first.length; --i >= 0;)
+			if (!equals(first[i], second[i]))
+				return false;
+		return true;
+	}
+
 	/**
 	 * Taken from org.aspectj.org.eclipse.jdt.core.compiler.CharOperation
 	 */