Create string_tokeniser.h

Author: greydoubt

string_tokeniser.h

@@ -0,0 +1,156 @@
+
+public
+class StringTokenizer implements Enumeration {
+    private int currentPosition;
+    private int maxPosition;
+    private String str;
+    private String delimiters;
+    private boolean retTokens;
+
+    /**
+     * Constructs a StringTokenizer on the specified String, using the
+     * specified delimiter set.
+     * @param str	   the input String
+     * @param delim        the delimiter String
+     * @param returnTokens returns delimiters as tokens or skip them
+     */
+    public StringTokenizer(String str, String delim, boolean returnTokens) {
+	currentPosition = 0;
+	this.str = str;
+	maxPosition = str.length();
+	delimiters = delim;
+	retTokens = returnTokens;
+    }
+
+    /**
+     * Constructs a StringTokenizer on the specified String, using the
+     * specified delimiter set.
+     * @param str	the input String
+     * @param delim the delimiter String
+     */
+    public StringTokenizer(String str, String delim) {
+	this(str, delim, false);
+    }
+
+    /**
+     * Constructs a StringTokenizer on the specified String, using the
+     * default delimiter set (which is " \t\n\r").
+     * @param str the String
+     */
+    public StringTokenizer(String str) {
+	this(str, " \t\n\r", false);
+    }
+
+    /**
+     * Skips delimiters.
+     */
+    private void skipDelimiters() {
+	while (!retTokens &&
+	       (currentPosition < maxPosition) &&
+	       (delimiters.indexOf(str.charAt(currentPosition)) >= 0)) {
+	    currentPosition++;
+	}
+    }
+
+    /**
+     * Returns true if more tokens exist.
+     */
+    public boolean hasMoreTokens() {
+	skipDelimiters();
+	return (currentPosition < maxPosition);
+    }
+
+    /**
+     * Returns the next token of the String.
+     * @exception NoSuchElementException If there are no more 
+     * tokens in the String.
+     */
+    public String nextToken() {
+	skipDelimiters();
+
+	if (currentPosition >= maxPosition) {
+	    throw new NoSuchElementException();
+	}
+
+	int start = currentPosition;
+	while ((currentPosition < maxPosition) && 
+	       (delimiters.indexOf(str.charAt(currentPosition)) < 0)) {
+	    currentPosition++;
+	}
+	if (retTokens && (start == currentPosition) &&
+	    (delimiters.indexOf(str.charAt(currentPosition)) >= 0)) {
+	    currentPosition++;
+	}
+	return str.substring(start, currentPosition);
+    }
+
+    /**
+     * Returns the next token, after switching to the new delimiter set.
+     * The new delimiter set remains the default after this call.
+     * @param delim the new delimiters
+     */
+    public String nextToken(String delim) {
+	delimiters = delim;
+	return nextToken();
+    }
+
+    /**
+     * Returns true if the Enumeration has more elements.
+     */
+    public boolean hasMoreElements() {
+	return hasMoreTokens();
+    }
+
+    /**
+     * Returns the next element in the Enumeration.
+     * @exception NoSuchElementException If there are no more elements 
+     * in the enumeration.
+     */
+    public Object nextElement() {
+	return nextToken();
+    }
+
+    /**
+     * Returns the next number of tokens in the String using
+     * the current deliminter set.  This is the number of times
+     * nextToken() can return before it will generate an exception.
+     * Use of this routine to count the number of tokens is faster
+     * than repeatedly calling nextToken() because the substrings
+     * are not constructed and returned for each token.
+     */
+    public int countTokens() {
+	int count = 0;
+	int currpos = currentPosition;
+
+	while (currpos < maxPosition) {
+	    /*
+	     * This is just skipDelimiters(); but it does not affect
+	     * currentPosition.
+	     */
+	    while (!retTokens &&
+		   (currpos < maxPosition) &&
+		   (delimiters.indexOf(str.charAt(currpos)) >= 0)) {
+		currpos++;
+	    }
+
+	    if (currpos >= maxPosition) {
+		break;
+	    }
+
+	    int start = currpos;
+	    while ((currpos < maxPosition) && 
+		   (delimiters.indexOf(str.charAt(currpos)) < 0)) {
+		currpos++;
+	    }
+	    if (retTokens && (start == currpos) &&
+		(delimiters.indexOf(str.charAt(currpos)) >= 0)) {
+		currpos++;
+	    }
+	    count++;
+
+	}
+	return count;
+    }
+}
+
+