/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (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.apache.org/licenses/LICENSE-2.0
 * 
 * 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 org.apache.commons.lang;

import java.math.BigDecimal;
import java.math.BigInteger;

Provides extra functionality for Java Number classes.
Author:
Apache Software Foundation, Rand McNeely, Steve Downey, Eric Pugh, Phil Steitz
Since:
1.0
Version:
$Id: NumberUtils.java 905636 2010-02-02 14:03:32Z niallp $
Deprecated:
Moved to org.apache.commons.lang.math.
            Class will be removed in Commons Lang 3.0./**
 * <p>Provides extra functionality for Java Number classes.</p>
 *
 * @author Apache Software Foundation
 * @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a>
 * @author <a href="mailto:steve.downey@netfolio.com">Steve Downey</a>
 * @author Eric Pugh
 * @author Phil Steitz
 * @since 1.0
 * @version $Id: NumberUtils.java 905636 2010-02-02 14:03:32Z niallp $
 * 
 * @deprecated Moved to org.apache.commons.lang.math.
 *             Class will be removed in Commons Lang 3.0.
 */
public final class NumberUtils {
    // DEPRECATED CLASS !!!
    
    
NumberUtils instances should NOT be constructed in standard programming.
Instead, the class should be used as NumberUtils.stringToInt("6");.
This constructor is public to permit tools that require a JavaBean instance
to operate.
/**
     * <p><code>NumberUtils</code> instances should NOT be constructed in standard programming.
     * Instead, the class should be used as <code>NumberUtils.stringToInt("6");</code>.</p>
     *
     * <p>This constructor is public to permit tools that require a JavaBean instance
     * to operate.</p>
     */
    public NumberUtils() {
      super();
    }

    //--------------------------------------------------------------------
    
    
Convert a String to an int, returning
zero if the conversion fails.
Params:
str –  the string to convert
Returns:
the int represented by the string, or zero if
 conversion fails/**
     * <p>Convert a <code>String</code> to an <code>int</code>, returning
     * <code>zero</code> if the conversion fails.</p>
     * 
     * @param str  the string to convert
     * @return the int represented by the string, or <code>zero</code> if
     *  conversion fails
     */
    public static int stringToInt(String str) {
        return stringToInt(str, 0);
    }

    
Convert a String to an int, returning a
default value if the conversion fails.
Params:
str –  the string to convert
defaultValue –  the default value
Returns:
the int represented by the string, or the default if conversion fails/**
     * <p>Convert a <code>String</code> to an <code>int</code>, returning a
     * default value if the conversion fails.</p>
     * 
     * @param str  the string to convert
     * @param defaultValue  the default value
     * @return the int represented by the string, or the default if conversion fails
     */
    public static int stringToInt(String str, int defaultValue) {
        try {
            return Integer.parseInt(str);
        } catch (NumberFormatException nfe) {
            return defaultValue;
        }
    }

    //--------------------------------------------------------------------
    
    // must handle Long, Float, Integer, Float, Short,
    //                  BigDecimal, BigInteger and Byte
    // useful methods:
    // Byte.decode(String)
    // Byte.valueOf(String,int radix)
    // Byte.valueOf(String)
    // Double.valueOf(String)
    // Float.valueOf(String)
    // new Float(String)
    // Integer.valueOf(String,int radix)
    // Integer.valueOf(String)
    // Integer.decode(String)
    // Integer.getInteger(String)
    // Integer.getInteger(String,int val)
    // Integer.getInteger(String,Integer val)
    // new Integer(String)
    // new Double(String)
    // new Byte(String)
    // new Long(String)
    // Long.getLong(String)
    // Long.getLong(String,int)
    // Long.getLong(String,Integer)
    // Long.valueOf(String,int)
    // Long.valueOf(String)
    // new Short(String)
    // Short.decode(String)
    // Short.valueOf(String,int)
    // Short.valueOf(String)
    // new BigDecimal(String)
    // new BigInteger(String)
    // new BigInteger(String,int radix)
    // Possible inputs:
    // 45 45.5 45E7 4.5E7 Hex Oct Binary xxxF xxxD xxxf xxxd
    // plus minus everything. Prolly more. A lot are not separable.

    
Turns a string value into a java.lang.Number.
First, the value is examined for a type qualifier on the end
('f','F','d','D','l','L').  If it is found, it starts 
trying to create successively larger types from the type specified
until one is found that can hold the value.
If a type specifier is not found, it will check for a decimal point
and then try successively larger types from Integer to
BigInteger and from Float to
BigDecimal.
If the string starts with 0x or -0x, it
will be interpreted as a hexadecimal integer.  Values with leading
0's will not be interpreted as octal.
Params:
val – String containing a number
Throws:
NumberFormatException – if the value cannot be converted
Returns:
Number created from the string/**
     * <p>Turns a string value into a java.lang.Number.</p>
     *
     * <p>First, the value is examined for a type qualifier on the end
     * (<code>'f','F','d','D','l','L'</code>).  If it is found, it starts 
     * trying to create successively larger types from the type specified
     * until one is found that can hold the value.</p>
     *
     * <p>If a type specifier is not found, it will check for a decimal point
     * and then try successively larger types from <code>Integer</code> to
     * <code>BigInteger</code> and from <code>Float</code> to
     * <code>BigDecimal</code>.</p>
     *
     * <p>If the string starts with <code>0x</code> or <code>-0x</code>, it
     * will be interpreted as a hexadecimal integer.  Values with leading
     * <code>0</code>'s will not be interpreted as octal.</p>
     *
     * @param val String containing a number
     * @return Number created from the string
     * @throws NumberFormatException if the value cannot be converted
     */
    public static Number createNumber(String val) throws NumberFormatException {
        if (val == null) {
            return null;
        }
        if (val.length() == 0) {
            throw new NumberFormatException("\"\" is not a valid number.");
        }
        if (val.length() == 1 && !Character.isDigit(val.charAt(0))) {
            throw new NumberFormatException(val + " is not a valid number.");
        }
        if (val.startsWith("--")) {
            // this is protection for poorness in java.lang.BigDecimal.
            // it accepts this as a legal value, but it does not appear 
            // to be in specification of class. OS X Java parses it to 
            // a wrong value.
            return null;
        }
        if (val.startsWith("0x") || val.startsWith("-0x")) {
            return createInteger(val);
        }   
        char lastChar = val.charAt(val.length() - 1);
        String mant;
        String dec;
        String exp;
        int decPos = val.indexOf('.');
        int expPos = val.indexOf('e') + val.indexOf('E') + 1;

        if (decPos > -1) {

            if (expPos > -1) {
                if (expPos < decPos) {
                    throw new NumberFormatException(val + " is not a valid number.");
                }
                dec = val.substring(decPos + 1, expPos);
            } else {
                dec = val.substring(decPos + 1);
            }
            mant = val.substring(0, decPos);
        } else {
            if (expPos > -1) {
                mant = val.substring(0, expPos);
            } else {
                mant = val;
            }
            dec = null;
        }
        if (!Character.isDigit(lastChar)) {
            if (expPos > -1 && expPos < val.length() - 1) {
                exp = val.substring(expPos + 1, val.length() - 1);
            } else {
                exp = null;
            }
            //Requesting a specific type..
            String numeric = val.substring(0, val.length() - 1);
            boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
            switch (lastChar) {
                case 'l' :
                case 'L' :
                    if (dec == null
                        && exp == null
                        && (numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
                        try {
                            return createLong(numeric);
                        } catch (NumberFormatException nfe) {
                            //Too big for a long
                        }
                        return createBigInteger(numeric);

                    }
                    throw new NumberFormatException(val + " is not a valid number.");
                case 'f' :
                case 'F' :
                    try {
                        Float f = NumberUtils.createFloat(numeric);
                        if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
                            //If it's too big for a float or the float value = 0 and the string
                            //has non-zeros in it, then float does not have the precision we want
                            return f;
                        }

                    } catch (NumberFormatException e) {
                        // ignore the bad number
                    }
                    //$FALL-THROUGH$
                case 'd' :
                case 'D' :
                    try {
                        Double d = NumberUtils.createDouble(numeric);
                        if (!(d.isInfinite() || (d.floatValue() == 0.0D && !allZeros))) {
                            return d;
                        }
                    } catch (NumberFormatException nfe) {
                        // empty catch
                    }
                    try {
                        return createBigDecimal(numeric);
                    } catch (NumberFormatException e) {
                        // empty catch
                    }
                    //$FALL-THROUGH$
                default :
                    throw new NumberFormatException(val + " is not a valid number.");

            }
        } else {
            //User doesn't have a preference on the return type, so let's start
            //small and go from there...
            if (expPos > -1 && expPos < val.length() - 1) {
                exp = val.substring(expPos + 1, val.length());
            } else {
                exp = null;
            }
            if (dec == null && exp == null) {
                //Must be an int,long,bigint
                try {
                    return createInteger(val);
                } catch (NumberFormatException nfe) {
                    // empty catch
                }
                try {
                    return createLong(val);
                } catch (NumberFormatException nfe) {
                    // empty catch
                }
                return createBigInteger(val);

            } else {
                //Must be a float,double,BigDec
                boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
                try {
                    Float f = createFloat(val);
                    if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
                        return f;
                    }
                } catch (NumberFormatException nfe) {
                    // empty catch
                }
                try {
                    Double d = createDouble(val);
                    if (!(d.isInfinite() || (d.doubleValue() == 0.0D && !allZeros))) {
                        return d;
                    }
                } catch (NumberFormatException nfe) {
                    // empty catch
                }

                return createBigDecimal(val);

            }

        }
    }

    
Utility method for createNumber(String).
Returns true if s is null.
Params:
s – the String to check
Returns:
if it is all zeros or null/**
     * <p>Utility method for {@link #createNumber(java.lang.String)}.</p>
     *
     * <p>Returns <code>true</code> if s is <code>null</code>.</p>
     * 
     * @param s the String to check
     * @return if it is all zeros or <code>null</code>
     */
    private static boolean isAllZeros(String s) {
        if (s == null) {
            return true;
        }
        for (int i = s.length() - 1; i >= 0; i--) {
            if (s.charAt(i) != '0') {
                return false;
            }
        }
        return s.length() > 0;
    }

    //--------------------------------------------------------------------
    
    
Convert a String to a Float.
Params:
val –  a String to convert
Throws:
NumberFormatException – if the value cannot be converted
Returns:
converted Float/**
     * <p>Convert a <code>String</code> to a <code>Float</code>.</p>
     * 
     * @param val  a <code>String</code> to convert
     * @return converted <code>Float</code>
     * @throws NumberFormatException if the value cannot be converted
     */
    public static Float createFloat(String val) {
        return Float.valueOf(val);
    }

    
Convert a String to a Double.
Params:
val –  a String to convert
Throws:
NumberFormatException – if the value cannot be converted
Returns:
converted Double/**
     * <p>Convert a <code>String</code> to a <code>Double</code>.</p>
     * 
     * @param val  a <code>String</code> to convert
     * @return converted <code>Double</code>
     * @throws NumberFormatException if the value cannot be converted
     */
    public static Double createDouble(String val) {
        return Double.valueOf(val);
    }

    
Convert a String to a Integer, handling
hex and octal notations.
Params:
val –  a String to convert
Throws:
NumberFormatException – if the value cannot be converted
Returns:
converted Integer/**
     * <p>Convert a <code>String</code> to a <code>Integer</code>, handling
     * hex and octal notations.</p>
     * 
     * @param val  a <code>String</code> to convert
     * @return converted <code>Integer</code>
     * @throws NumberFormatException if the value cannot be converted
     */
    public static Integer createInteger(String val) {
        // decode() handles 0xAABD and 0777 (hex and octal) as well.
        return Integer.decode(val);
    }

    
Convert a String to a Long.
Params:
val –  a String to convert
Throws:
NumberFormatException – if the value cannot be converted
Returns:
converted Long/**
     * <p>Convert a <code>String</code> to a <code>Long</code>.</p>
     * 
     * @param val  a <code>String</code> to convert
     * @return converted <code>Long</code>
     * @throws NumberFormatException if the value cannot be converted
     */
    public static Long createLong(String val) {
        return Long.valueOf(val);
    }

    
Convert a String to a BigInteger.
Params:
val –  a String to convert
Throws:
NumberFormatException – if the value cannot be converted
Returns:
converted BigInteger/**
     * <p>Convert a <code>String</code> to a <code>BigInteger</code>.</p>
     * 
     * @param val  a <code>String</code> to convert
     * @return converted <code>BigInteger</code>
     * @throws NumberFormatException if the value cannot be converted
     */
    public static BigInteger createBigInteger(String val) {
        BigInteger bi = new BigInteger(val);
        return bi;
    }

    
Convert a String to a BigDecimal.
Params:
val –  a String to convert
Throws:
NumberFormatException – if the value cannot be converted
Returns:
converted BigDecimal/**
     * <p>Convert a <code>String</code> to a <code>BigDecimal</code>.</p>
     * 
     * @param val  a <code>String</code> to convert
     * @return converted <code>BigDecimal</code>
     * @throws NumberFormatException if the value cannot be converted
     */
    public static BigDecimal createBigDecimal(String val) {
        BigDecimal bd = new BigDecimal(val);
        return bd;
    }

    //--------------------------------------------------------------------
    
    
Gets the minimum of three long values.
Params:
a –  value 1
b –  value 2
c –  value 3
Returns:
 the smallest of the values/**
     * <p>Gets the minimum of three <code>long</code> values.</p>
     * 
     * @param a  value 1
     * @param b  value 2
     * @param c  value 3
     * @return  the smallest of the values
     */
    public static long minimum(long a, long b, long c) {
        if (b < a) {
            a = b;
        }
        if (c < a) {
            a = c;
        }
        return a;
    }

    
Gets the minimum of three int values.
Params:
a –  value 1
b –  value 2
c –  value 3
Returns:
 the smallest of the values/**
     * <p>Gets the minimum of three <code>int</code> values.</p>
     * 
     * @param a  value 1
     * @param b  value 2
     * @param c  value 3
     * @return  the smallest of the values
     */
    public static int minimum(int a, int b, int c) {
        if (b < a) {
            a = b;
        }
        if (c < a) {
            a = c;
        }
        return a;
    }

    
Gets the maximum of three long values.
Params:
a –  value 1
b –  value 2
c –  value 3
Returns:
 the largest of the values/**
     * <p>Gets the maximum of three <code>long</code> values.</p>
     * 
     * @param a  value 1
     * @param b  value 2
     * @param c  value 3
     * @return  the largest of the values
     */
    public static long maximum(long a, long b, long c) {
        if (b > a) {
            a = b;
        }
        if (c > a) {
            a = c;
        }
        return a;
    }

    
Gets the maximum of three int values.
Params:
a –  value 1
b –  value 2
c –  value 3
Returns:
 the largest of the values/**
     * <p>Gets the maximum of three <code>int</code> values.</p>
     * 
     * @param a  value 1
     * @param b  value 2
     * @param c  value 3
     * @return  the largest of the values
     */
    public static int maximum(int a, int b, int c) {
        if (b > a) {
            a = b;
        }
        if (c > a) {
            a = c;
        }
        return a;
    }

    //--------------------------------------------------------------------
    
    
Compares two doubles for order.
This method is more comprehensive than the standard Java greater
than, less than and equals operators.

 
It returns -1 if the first value is less than the second.
 
It returns +1 if the first value is greater than the second.
 
It returns 0 if the values are equal.


The ordering is as follows, largest to smallest:

 
NaN
 
Positive infinity
 
Maximum double
 
Normal positive numbers
 
+0.0
 
-0.0
 
Normal negative numbers
 
Minimum double (-Double.MAX_VALUE)
 
Negative infinity


Comparing NaN with NaN will
return 0.
Params:
lhs –  the first double
rhs –  the second double
Returns:
-1 if lhs is less, +1 if greater,
 0 if equal to rhs/**
     * <p>Compares two <code>doubles</code> for order.</p>
     *
     * <p>This method is more comprehensive than the standard Java greater
     * than, less than and equals operators.</p>
     * <ul>
     *  <li>It returns <code>-1</code> if the first value is less than the second.
     *  <li>It returns <code>+1</code> if the first value is greater than the second.
     *  <li>It returns <code>0</code> if the values are equal.
     * </ul>
     *
     * <p>
     * The ordering is as follows, largest to smallest:
     * <ul>
     *  <li>NaN
     *  <li>Positive infinity
     *  <li>Maximum double
     *  <li>Normal positive numbers
     *  <li>+0.0
     *  <li>-0.0
     *  <li>Normal negative numbers
     *  <li>Minimum double (-Double.MAX_VALUE)
     *  <li>Negative infinity
     * </ul>
     * </p>
     *
     * <p>Comparing <code>NaN</code> with <code>NaN</code> will
     * return <code>0</code>.</p>
     * 
     * @param lhs  the first <code>double</code>
     * @param rhs  the second <code>double</code>
     * @return <code>-1</code> if lhs is less, <code>+1</code> if greater,
     *  <code>0</code> if equal to rhs
     */
    public static int compare(double lhs, double rhs) {
        if (lhs < rhs) {
            return -1;
        }
        if (lhs > rhs) {
            return +1;
        }
        // Need to compare bits to handle 0.0 == -0.0 being true
        // compare should put -0.0 < +0.0
        // Two NaNs are also == for compare purposes
        // where NaN == NaN is false
        long lhsBits = Double.doubleToLongBits(lhs);
        long rhsBits = Double.doubleToLongBits(rhs);
        if (lhsBits == rhsBits) {
            return 0;
        }
        // Something exotic! A comparison to NaN or 0.0 vs -0.0
        // Fortunately NaN's long is > than everything else
        // Also negzeros bits < poszero
        // NAN: 9221120237041090560
        // MAX: 9218868437227405311
        // NEGZERO: -9223372036854775808
        if (lhsBits < rhsBits) {
            return -1;
        } else {
            return +1;
        }
    }
    
    
Compares two floats for order.
This method is more comprehensive than the standard Java greater than,
less than and equals operators.

 
It returns -1 if the first value is less than the second.
 
It returns +1 if the first value is greater than the second.
 
It returns 0 if the values are equal.

 The ordering is as follows, largest to smallest:

NaN
Positive infinity
Maximum float
Normal positive numbers
+0.0
-0.0
Normal negative numbers
Minimum float (-Float.MAX_VALUE)
Negative infinity

Comparing NaN with NaN will return
0.
Params:
lhs –  the first float
rhs –  the second float
Returns:
-1 if lhs is less, +1 if greater,
 0 if equal to rhs/**
     * <p>Compares two floats for order.</p>
     *
     * <p>This method is more comprehensive than the standard Java greater than,
     * less than and equals operators.</p>
     * <ul>
     *  <li>It returns <code>-1</code> if the first value is less than the second.
     *  <li>It returns <code>+1</code> if the first value is greater than the second.
     *  <li>It returns <code>0</code> if the values are equal.
     * </ul>
     *
     * <p> The ordering is as follows, largest to smallest:
     * <ul>
     * <li>NaN
     * <li>Positive infinity
     * <li>Maximum float
     * <li>Normal positive numbers
     * <li>+0.0
     * <li>-0.0
     * <li>Normal negative numbers
     * <li>Minimum float (-Float.MAX_VALUE)
     * <li>Negative infinity
     * </ul>
     *
     * <p>Comparing <code>NaN</code> with <code>NaN</code> will return
     * <code>0</code>.</p>
     * 
     * @param lhs  the first <code>float</code>
     * @param rhs  the second <code>float</code>
     * @return <code>-1</code> if lhs is less, <code>+1</code> if greater,
     *  <code>0</code> if equal to rhs
     */
    public static int compare(float lhs, float rhs) {
        if (lhs < rhs) {
            return -1;
        }
        if (lhs > rhs) {
            return +1;
        }
        //Need to compare bits to handle 0.0 == -0.0 being true
        // compare should put -0.0 < +0.0
        // Two NaNs are also == for compare purposes
        // where NaN == NaN is false
        int lhsBits = Float.floatToIntBits(lhs);
        int rhsBits = Float.floatToIntBits(rhs);
        if (lhsBits == rhsBits) {
            return 0;
        }
        //Something exotic! A comparison to NaN or 0.0 vs -0.0
        //Fortunately NaN's int is > than everything else
        //Also negzeros bits < poszero
        //NAN: 2143289344
        //MAX: 2139095039
        //NEGZERO: -2147483648
        if (lhsBits < rhsBits) {
            return -1;
        } else {
            return +1;
        }
    }
    
    //--------------------------------------------------------------------
    
    
Checks whether the String contains only
digit characters.
Null and empty String will return
false.
Params:
str –  the String to check
Returns:
true if str contains only unicode numeric/**
     * <p>Checks whether the <code>String</code> contains only
     * digit characters.</p>
     *
     * <p><code>Null</code> and empty String will return
     * <code>false</code>.</p>
     *
     * @param str  the <code>String</code> to check
     * @return <code>true</code> if str contains only unicode numeric
     */
    public static boolean isDigits(String str) {
        if ((str == null) || (str.length() == 0)) {
            return false;
        }
        for (int i = 0; i < str.length(); i++) {
            if (!Character.isDigit(str.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    
Checks whether the String a valid Java number.
Valid numbers include hexadecimal marked with the 0x
qualifier, scientific notation and numbers marked with a type
qualifier (e.g. 123L).
Null and empty String will return
false.
Params:
str –  the String to check
Returns:
true if the string is a correctly formatted number/**
     * <p>Checks whether the String a valid Java number.</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><code>Null</code> and empty String will return
     * <code>false</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 (StringUtils.isEmpty(str)) {
            return false;
        }
        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) {
            if (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 (!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
                return foundDigit && !hasExp;
            }
            // 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;
    }
}