package dr.inference.trace;
/**
* Detect number type from a string.
* <code>isNumber</code> is modified from org.apache.commons.lang3.math.NumberUtils
* to handle NaN and Inf.
*
* @author Walter Xie
*/
public class NumberUtils {
/**
* <p>Checks whether the <code>String</code> does not contain decimal point.</p>
* <p>
* <p><code>Null</code> and empty String will return <code>false</code>.</p>
* <p><code>Double.NaN</code>, <code>Double.NEGATIVE_INFINITY</code>,
* and <code>Double.POSITIVE_INFINITY</code> will return <code>true</code>.</p>
*
* @param str the <code>String</code> to check
* @return <code>true</code> if str contains only Unicode numeric
*/
public static boolean hasDecimalPoint(String str) {
if (str == null || str.length() == 0)
return false;
if (str.equalsIgnoreCase(Double.toString(Double.NaN)) ||
str.equalsIgnoreCase(Double.toString(Double.NEGATIVE_INFINITY)) ||
str.equalsIgnoreCase(Double.toString(Double.POSITIVE_INFINITY)))
return true;
return str.contains(".");
}
/**
* <p>Checks whether the String a valid Java number.</p>
* <p>
* <p>Valid numbers include hexadecimal marked with the <code>0x</code>
* qualifier, scientific notation and numbers marked with a type
* qualifier (e.g. 123L).</p>
* <p>
* <p><code>Null</code> and empty String will return <code>false</code>.</p>
* <p><code>Double.NaN</code>, <code>Double.NEGATIVE_INFINITY</code>,
* and <code>Double.POSITIVE_INFINITY</code> will return <code>true</code>.</p>
*
* @param str the <code>String</code> to check
* @return <code>true</code> if the string is a correctly formatted number
*/
public static boolean isNumber(String str) {
if (str == null || str.length() == 0) {
return false;
}
// modified
if (str.equalsIgnoreCase(Double.toString(Double.NaN)) ||
str.equalsIgnoreCase(Double.toString(Double.NEGATIVE_INFINITY)) ||
str.equalsIgnoreCase(Double.toString(Double.POSITIVE_INFINITY)))
return true;
char[] chars = str.toCharArray();
int sz = chars.length;
boolean hasExp = false;
boolean hasDecPoint = false;
boolean allowSigns = false;
boolean foundDigit = false;
// deal with any possible sign up front
int start = (chars[0] == '-') ? 1 : 0;
if (sz > start + 1 && chars[start] == '0' && chars[start + 1] == 'x') {
int i = start + 2;
if (i == sz) {
return false; // str == "0x"
}
// checking hex (it can't be anything else)
for (; i < chars.length; i++) {
if ((chars[i] < '0' || chars[i] > '9')
&& (chars[i] < 'a' || chars[i] > 'f')
&& (chars[i] < 'A' || chars[i] > 'F')) {
return false;
}
}
return true;
}
sz--; // don't want to loop to the last char, check it afterwords
// for type qualifiers
int i = start;
// loop to the next to last char or to the last char if we need another digit to
// make a valid number (e.g. chars[0..5] = "1234E")
while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) {
if (chars[i] >= '0' && chars[i] <= '9') {
foundDigit = true;
allowSigns = false;
} else if (chars[i] == '.') {
if (hasDecPoint || hasExp) {
// two decimal points or dec in exponent
return false;
}
hasDecPoint = true;
} else if (chars[i] == 'e' || chars[i] == 'E') {
// we've already taken care of hex.
if (hasExp) {
// two E's
return false;
}
if (!foundDigit) {
return false;
}
hasExp = true;
allowSigns = true;
} else if (chars[i] == '+' || chars[i] == '-') {
if (!allowSigns) {
return false;
}
allowSigns = false;
foundDigit = false; // we need a digit after the E
} else {
return false;
}
i++;
}
if (i < chars.length) {
if (chars[i] >= '0' && chars[i] <= '9') {
// no type qualifier, OK
return true;
}
if (chars[i] == 'e' || chars[i] == 'E') {
// can't have an E at the last byte
return false;
}
if (chars[i] == '.') {
if (hasDecPoint || hasExp) {
// two decimal points or dec in exponent
return false;
}
// single trailing decimal point after non-exponent is ok
return foundDigit;
}
if (!allowSigns
&& (chars[i] == 'd'
|| chars[i] == 'D'
|| chars[i] == 'f'
|| chars[i] == 'F')) {
return foundDigit;
}
if (chars[i] == 'l'
|| chars[i] == 'L') {
// not allowing L with an exponent or decimal point
return foundDigit && !hasExp && !hasDecPoint;
}
// last character is illegal
return false;
}
// allowSigns is true iff the val ends in 'E'
// found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
return !allowSigns && foundDigit;
}
}