/*
    * 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.jexl3;
  
  import org.apache.commons.jexl3.introspection.JexlMethod;
  
  import java.lang.reflect.Array;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.math.MathContext;
  import java.util.Collection;
  import java.util.Map;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import static java.lang.StrictMath.floor;
  
  /**
   * Perform arithmetic, implements JexlOperator methods.
   *
   * <p>This is the class to derive to implement new operator behaviors.</p>
   *
   * <p>The 5 base arithmetic operators (+, - , *, /, %) follow the same evaluation rules regarding their arguments.</p>
   * <ol>
   *   <li>If both are null, result is 0</li>
   *   <li>If either is a BigDecimal, coerce both to BigDecimal and perform operation</li>
   *   <li>If either is a floating point number, coerce both to Double and perform operation</li>
   *   <li>Else treat as BigInteger, perform operation and attempt to narrow result:
   *     <ol>
   *       <li>if both arguments can be narrowed to Integer, narrow result to Integer</li>
   *       <li>if both arguments can be narrowed to Long, narrow result to Long</li>
   *       <li>Else return result as BigInteger</li>
   *     </ol>
   *   </li>
   * </ol>
   *
   * Note that the only exception thrown by JexlArithmetic is and must be ArithmeticException.
   *
   * @see JexlOperator
   * @since 2.0
   */
  public class JexlArithmetic {
  
      /** Marker class for null operand exceptions. */
      public static class NullOperand extends ArithmeticException {
          private static final long serialVersionUID = 4720876194840764770L;
      }
  
      /** Double.MAX_VALUE as BigDecimal. */
      protected static final BigDecimal BIGD_DOUBLE_MAX_VALUE = BigDecimal.valueOf(Double.MAX_VALUE);
  
      /** Double.MIN_VALUE as BigDecimal. */
      protected static final BigDecimal BIGD_DOUBLE_MIN_VALUE = BigDecimal.valueOf(Double.MIN_VALUE);
  
      /** Long.MAX_VALUE as BigInteger. */
      protected static final BigInteger BIGI_LONG_MAX_VALUE = BigInteger.valueOf(Long.MAX_VALUE);
  
      /** Long.MIN_VALUE as BigInteger. */
      protected static final BigInteger BIGI_LONG_MIN_VALUE = BigInteger.valueOf(Long.MIN_VALUE);
  
      /** Default BigDecimal scale. */
      protected static final int BIGD_SCALE = -1;
  
      /** Whether this JexlArithmetic instance behaves in strict or lenient mode. */
      private final boolean strict;
  
      /** The big decimal math context. */
      private final MathContext mathContext;
  
      /** The big decimal scale. */
      private final int mathScale;
  
      /** The dynamic constructor. */
      private final Constructor<? extends JexlArithmetic> ctor;
  
      /**
       * Creates a JexlArithmetic.
       * <p>If you derive your own arithmetic, implement the
       * other constructor that may be needed when dealing with options.
       *
      * @param astrict whether this arithmetic is strict or lenient
      */
     public JexlArithmetic(final boolean astrict) {
         this(astrict, null, Integer.MIN_VALUE);
     }
 
     /**
      * Creates a JexlArithmetic.
      * <p>The constructor to define in derived classes.
      *
      * @param astrict     whether this arithmetic is lenient or strict
      * @param bigdContext the math context instance to use for +,-,/,*,% operations on big decimals.
      * @param bigdScale   the scale used for big decimals.
      */
     public JexlArithmetic(final boolean astrict, final MathContext bigdContext, final int bigdScale) {
         this.strict = astrict;
         this.mathContext = bigdContext == null ? MathContext.DECIMAL128 : bigdContext;
         this.mathScale = bigdScale == Integer.MIN_VALUE ? BIGD_SCALE : bigdScale;
         Constructor<? extends JexlArithmetic> actor = null;
         try {
             actor = getClass().getConstructor(boolean.class, MathContext.class, int.class);
         } catch (final Exception xany) {
             // ignore
         }
         this.ctor = actor;
     }
 
     /**
      * Apply options to this arithmetic which eventually may create another instance.
      * @see #createWithOptions(boolean, java.math.MathContext, int)
      *
      * @param options the {@link JexlEngine.Options} to use
      * @return an arithmetic with those options set
      */
     public JexlArithmetic options(final JexlOptions options) {
         if (options != null) {
             final boolean ostrict = options.isStrictArithmetic();
             MathContext bigdContext = options.getMathContext();
             if (bigdContext == null) {
                 bigdContext = getMathContext();
             }
             int bigdScale = options.getMathScale();
             if (bigdScale == Integer.MIN_VALUE) {
                 bigdScale = getMathScale();
             }
             if (ostrict != isStrict()
                 || bigdScale != getMathScale()
                 || bigdContext != getMathContext()) {
                 return createWithOptions(ostrict, bigdContext, bigdScale);
             }
         }
         return this;
     }
 
     /**
      * Apply options to this arithmetic which eventually may create another instance.
      * @see #createWithOptions(boolean, java.math.MathContext, int)
      *
      * @param options the {@link JexlEngine.Options} to use
      * @return an arithmetic with those options set
      * @deprecated 3.2
      */
     @Deprecated
     public JexlArithmetic options(final JexlEngine.Options options) {
         if (options != null) {
             Boolean ostrict = options.isStrictArithmetic();
             if (ostrict == null) {
                 ostrict = isStrict();
             }
             MathContext bigdContext = options.getArithmeticMathContext();
             if (bigdContext == null) {
                 bigdContext = getMathContext();
             }
             int bigdScale = options.getArithmeticMathScale();
             if (bigdScale == Integer.MIN_VALUE) {
                 bigdScale = getMathScale();
             }
             if (ostrict != isStrict()
                 || bigdScale != getMathScale()
                 || bigdContext != getMathContext()) {
                 return createWithOptions(ostrict, bigdContext, bigdScale);
             }
         }
         return this;
     }
 
     /**
      * Apply options to this arithmetic which eventually may create another instance.
      * @see #createWithOptions(boolean, java.math.MathContext, int)
      *
      * @param context the context that may extend {@link JexlContext.OptionsHandle} to use
      * @return a new arithmetic instance or this
      * @since 3.1
      */
     public JexlArithmetic options(final JexlContext context) {
         if (context instanceof JexlContext.OptionsHandle) {
             return options(((JexlContext.OptionsHandle) context).getEngineOptions());
         }
         if (context instanceof JexlEngine.Options) {
             return options((JexlEngine.Options) context);
         }
         return this;
     }
 
     /**
      * Creates a JexlArithmetic instance.
      * Called by options(...) method when another instance of the same class of arithmetic is required.
      * @see #options(org.apache.commons.jexl3.JexlEngine.Options)
      *
      * @param astrict     whether this arithmetic is lenient or strict
      * @param bigdContext the math context instance to use for +,-,/,*,% operations on big decimals.
      * @param bigdScale   the scale used for big decimals.
      * @return default is a new JexlArithmetic instance
      * @since 3.1
      */
     protected JexlArithmetic createWithOptions(final boolean astrict, final MathContext bigdContext, final int bigdScale) {
         if (ctor != null) {
             try {
                 return ctor.newInstance(astrict, bigdContext, bigdScale);
             } catch (IllegalAccessException | IllegalArgumentException
                     | InstantiationException | InvocationTargetException xany) {
                 // it was worth the try
             }
         }
         return new JexlArithmetic(astrict, bigdContext, bigdScale);
     }
 
     /**
      * The interface that uberspects JexlArithmetic classes.
      * <p>This allows overloaded operator methods discovery.</p>
      */
     public interface Uberspect {
         /**
          * Checks whether this uberspect has overloads for a given operator.
          *
          * @param operator the operator to check
          * @return true if an overload exists, false otherwise
          */
         boolean overloads(JexlOperator operator);
 
         /**
          * Gets the most specific method for an operator.
          *
          * @param operator the operator
          * @param arg      the arguments
          * @return the most specific method or null if no specific override could be found
          */
         JexlMethod getOperator(JexlOperator operator, Object... arg);
     }
 
     /**
      * Helper interface used when creating an array literal.
      *
      * <p>The default implementation creates an array and attempts to type it strictly.</p>
      *
      * <ul>
      *   <li>If all objects are of the same type, the array returned will be an array of that same type</li>
      *   <li>If all objects are Numbers, the array returned will be an array of Numbers</li>
      *   <li>If all objects are convertible to a primitive type, the array returned will be an array
      *       of the primitive type</li>
      * </ul>
      */
     public interface ArrayBuilder {
 
         /**
          * Adds a literal to the array.
          *
          * @param value the item to add
          */
         void add(Object value);
 
         /**
          * Creates the actual "array" instance.
          *
          * @param extended true when the last argument is ', ...'
          * @return the array
          */
         Object create(boolean extended);
     }
 
     /**
      * Called by the interpreter when evaluating a literal array.
      *
      * @param size the number of elements in the array
      * @return the array builder
      */
     public ArrayBuilder arrayBuilder(final int size) {
         return new org.apache.commons.jexl3.internal.ArrayBuilder(size);
     }
 
     /**
      * Helper interface used when creating a set literal.
      * <p>The default implementation creates a java.util.HashSet.</p>
      */
     public interface SetBuilder {
         /**
          * Adds a literal to the set.
          *
          * @param value the item to add
          */
         void add(Object value);
 
         /**
          * Creates the actual "set" instance.
          *
          * @return the set
          */
         Object create();
     }
 
     /**
      * Called by the interpreter when evaluating a literal set.
      *
      * @param size the number of elements in the set
      * @return the array builder
      */
     public SetBuilder setBuilder(final int size) {
         return new org.apache.commons.jexl3.internal.SetBuilder(size);
     }
 
     /**
      * Helper interface used when creating a map literal.
      * <p>The default implementation creates a java.util.HashMap.</p>
      */
     public interface MapBuilder {
         /**
          * Adds a new entry to the map.
          *
          * @param key   the map entry key
          * @param value the map entry value
          */
         void put(Object key, Object value);
 
         /**
          * Creates the actual "map" instance.
          *
          * @return the map
          */
         Object create();
     }
 
     /**
      * Called by the interpreter when evaluating a literal map.
      *
      * @param size the number of elements in the map
      * @return the map builder
      */
     public MapBuilder mapBuilder(final int size) {
         return new org.apache.commons.jexl3.internal.MapBuilder(size);
     }
 
     /**
      * Creates a literal range.
      * <p>The default implementation only accepts integers and longs.</p>
      *
      * @param from the included lower bound value (null if none)
      * @param to   the included upper bound value (null if none)
      * @return the range as an iterable
      * @throws ArithmeticException as an option if creation fails
      */
     public Iterable<?> createRange(final Object from, final Object to) throws ArithmeticException {
         final long lfrom = toLong(from);
         final long lto = toLong(to);
         if ((lfrom >= Integer.MIN_VALUE && lfrom <= Integer.MAX_VALUE)
                 && (lto >= Integer.MIN_VALUE && lto <= Integer.MAX_VALUE)) {
             return org.apache.commons.jexl3.internal.IntegerRange.create((int) lfrom, (int) lto);
         }
         return org.apache.commons.jexl3.internal.LongRange.create(lfrom, lto);
     }
 
     /**
      * Checks if an operand is considered null.
      * @param value the operand
      * @return true if operand is considered null
      */
     protected boolean isNullOperand(final Object value) {
         return value == null;
     }
 
     /**
      * Throws an NullOperand exception if arithmetic is strict-cast.
      * <p>This method is called by the cast methods ({@link #toBoolean(boolean, Object)},
      * {@link #toInteger(boolean, Object)}, {@link #toDouble(boolean, Object)},
      * {@link #toString(boolean, Object)}, {@link #toBigInteger(boolean, Object)},
      * {@link #toBigDecimal(boolean, Object)}) when they encounter a null argument.</p>
      *
      * @param strictCast whether strict cast is required
      * @param defaultValue the default value to return, if not strict
      * @param <T> the value type
      * @return the default value is strict is false
      * @throws JexlArithmetic.NullOperand if strict-cast
      * @since 3.3
      */
     protected <T> T controlNullOperand(final boolean strictCast, final T defaultValue) {
         if (strictCast) {
             throw new NullOperand();
         }
         return defaultValue;
     }
 
     /**
      * The result of +,/,-,*,% when both operands are null.
      * @param operator the actual operator
      * @return Integer(0) if lenient
      * @throws  JexlArithmetic.NullOperand if strict-cast
      * @since 3.3
      */
     protected Object controlNullNullOperands(final JexlOperator operator) {
         if (isStrict(operator)) {
             throw new NullOperand();
         }
         return 0;
     }
 
     /**
      * Coerce to a primitive boolean.
      * <p>Double.NaN, null, "false" and empty string coerce to false.</p>
      *
      * @param val value to coerce
      * @param strict true if the calling operator or casting is strict, false otherwise
      * @return the boolean value if coercion is possible, true if value was not null.
      */
     protected boolean toBoolean(final boolean strict, final Object val) {
         return isNullOperand(val)? controlNullOperand(strict, false) : toBoolean(val);
     }
 
     /**
      * Coerce to a primitive boolean.
      * <p>Double.NaN, null, "false" and empty string coerce to false.</p>
      *
      * @param val value to coerce
      * @return the boolean value if coercion is possible, true if value was not null.
      */
     public boolean toBoolean(final Object val) {
         if (val instanceof Boolean) {
             return ((Boolean) val);
         }
         if (val instanceof Number) {
             final double number = toDouble(strict, val);
             return !Double.isNaN(number) && number != 0.d;
         }
         if (val instanceof AtomicBoolean) {
             return ((AtomicBoolean) val).get();
         }
         if (val instanceof String) {
             final String strval = val.toString();
             return !strval.isEmpty() && !"false".equals(strval);
         }
         if (val == null) {
             return controlNullOperand(strict, false);
         }
         // non-null value is true
         return true;
     }
 
     /**
      * Coerce to a primitive int.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param strict true if the calling operator or casting is strict, false otherwise
      * @param val value to coerce
      * @return the value coerced to int
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      * @since 3.3
      */
     protected int toInteger(final boolean strict, final Object val) {
         return isNullOperand(val)? controlNullOperand(strict, 0) : toInteger(val);
     }
 
     /**
      * Coerce to a primitive int.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param val value to coerce
      * @return the value coerced to int
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      */
     public int toInteger(final Object val) {
         if (val instanceof Double) {
             final double dval = (Double) val;
             return Double.isNaN(dval)? 0 : (int) dval;
         }
         if (val instanceof Number) {
             return ((Number) val).intValue();
         }
         if (val instanceof String) {
             return parseInteger((String) val);
         }
         if (val instanceof Boolean) {
             return ((Boolean) val) ? 1 : 0;
         }
         if (val instanceof AtomicBoolean) {
             return ((AtomicBoolean) val).get() ? 1 : 0;
         }
         if (val instanceof Character) {
             return ((Character) val);
         }
         if (val == null) {
             return controlNullOperand(strict, 0);
         }
         throw new ArithmeticException("Integer coercion: "
                 + val.getClass().getName() + ":(" + val + ")");
     }
 
     /**
      * Coerce to a primitive long.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param strict true if the calling operator or casting is strict, false otherwise
      * @param val value to coerce
      * @return the value coerced to long
      * @throws ArithmeticException if value is null and mode is strict or if coercion is not possible
      * @since 3.3
      */
     protected long toLong(final boolean strict, final Object val) {
         return isNullOperand(val)? controlNullOperand(strict, 0L) : toLong(val);
     }
 
     /**
      * Coerce to a primitive long.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param val value to coerce
      * @return the value coerced to long
      * @throws ArithmeticException if value is null and mode is strict or if coercion is not possible
      */
     public long toLong(final Object val) {
         if (val instanceof Double) {
             final double dval = (Double) val;
             return Double.isNaN(dval)? 0L : (long) dval;
         }
         if (val instanceof Number) {
             return ((Number) val).longValue();
         }
         if (val instanceof String) {
             return parseLong((String) val);
         }
         if (val instanceof Boolean) {
             return ((Boolean) val) ? 1L : 0L;
         }
         if (val instanceof AtomicBoolean) {
             return ((AtomicBoolean) val).get() ? 1L : 0L;
         }
         if (val instanceof Character) {
             return ((Character) val);
         }
         if (val == null) {
             return controlNullOperand(strict, 0L);
         }
         throw new ArithmeticException("Long coercion: "
                 + val.getClass().getName() + ":(" + val + ")");
     }
 
     /**
      * Coerce to a BigInteger.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param strict true if the calling operator or casting is strict, false otherwise
      * @param val the object to be coerced.
      * @return a BigDecimal
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      * @since 3.3
      */
     protected BigInteger toBigInteger(final boolean strict, final Object val) {
         return isNullOperand(val)? controlNullOperand(strict, BigInteger.ZERO) : toBigInteger(val);
     }
 
     /**
      * Coerce to a BigInteger.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param val the object to be coerced.
      * @return a BigDecimal
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      */
     public BigInteger toBigInteger(final Object val) {
         if (val instanceof BigInteger) {
             return (BigInteger) val;
         }
         if (val instanceof Double) {
             final Double dval = (Double) val;
             if (Double.isNaN(dval)) {
                 return BigInteger.ZERO;
             }
             return BigInteger.valueOf(dval.longValue());
         }
         if (val instanceof BigDecimal) {
             return ((BigDecimal) val).toBigInteger();
         }
         if (val instanceof Number) {
             return BigInteger.valueOf(((Number) val).longValue());
         }
         if (val instanceof Boolean) {
             return BigInteger.valueOf(((Boolean) val) ? 1L : 0L);
         }
         if (val instanceof AtomicBoolean) {
             return BigInteger.valueOf(((AtomicBoolean) val).get() ? 1L : 0L);
         }
         if (val instanceof String) {
             return parseBigInteger((String) val);
         }
         if (val instanceof Character) {
             final int i = ((Character) val);
             return BigInteger.valueOf(i);
         }
         if (val == null) {
             return controlNullOperand(strict, BigInteger.ZERO);
         }
         throw new ArithmeticException("BigInteger coercion: "
                 + val.getClass().getName() + ":(" + val + ")");
     }
 
     /**
      * Coerce to a BigDecimal.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param strict true if the calling operator or casting is strict, false otherwise
      * @param val the object to be coerced.
      * @return a BigDecimal.
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      * @since 3.3
      */
     protected BigDecimal toBigDecimal(final boolean strict, final Object val) {
         return isNullOperand(val)? controlNullOperand(strict, BigDecimal.ZERO) : toBigDecimal(val);
     }
 
     /**
      * Coerce to a BigDecimal.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param val the object to be coerced.
      * @return a BigDecimal.
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      */
     public BigDecimal toBigDecimal(final Object val) {
         if (val instanceof BigDecimal) {
             return roundBigDecimal((BigDecimal) val);
         }
         if (val instanceof Double) {
             if (Double.isNaN(((Double) val))) {
                 return BigDecimal.ZERO;
             }
             return roundBigDecimal(new BigDecimal(val.toString(), getMathContext()));
         }
         if (val instanceof Number) {
             return roundBigDecimal(new BigDecimal(val.toString(), getMathContext()));
         }
         if (val instanceof Boolean) {
             return BigDecimal.valueOf(((Boolean) val) ? 1. : 0.);
         }
         if (val instanceof AtomicBoolean) {
             return BigDecimal.valueOf(((AtomicBoolean) val).get() ? 1L : 0L);
         }
         if (val instanceof String) {
             final String string = (String) val;
             if ("".equals(string)) {
                 return BigDecimal.ZERO;
             }
             return roundBigDecimal(new BigDecimal(string, getMathContext()));
         }
         if (val instanceof Character) {
             final int i = ((Character) val);
             return new BigDecimal(i);
         }
         if (val == null) {
             return controlNullOperand(strict, BigDecimal.ZERO);
         }
         throw new ArithmeticException("BigDecimal coercion: "
                 + val.getClass().getName() + ":(" + val + ")");
     }
 
     /**
      * Coerce to a primitive double.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param strict true if the calling operator or casting is strict, false otherwise
      * @param val value to coerce.
      * @return The double coerced value.
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      * @since 3.3
      */
     protected double toDouble(final boolean strict, final Object val) {
         return isNullOperand(val)? controlNullOperand(strict, 0.d) : toDouble(val);
     }
 
     /**
      * Coerce to a primitive double.
      * <p>Double.NaN, null and empty string coerce to zero.</p>
      * <p>Boolean false is 0, true is 1.</p>
      *
      * @param val value to coerce.
      * @return The double coerced value.
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      */
     public double toDouble(final Object val) {
         if (val instanceof Double) {
             return ((Double) val);
         }
         if (val instanceof Number) {
             //The below construct is used rather than ((Number)val).doubleValue() to ensure
             //equality between comparing new Double( 6.4 / 3 ) and the jexl expression of 6.4 / 3
             return Double.parseDouble(String.valueOf(val));
         }
         if (val instanceof Boolean) {
             return ((Boolean) val) ? 1. : 0.;
         }
         if (val instanceof AtomicBoolean) {
             return ((AtomicBoolean) val).get() ? 1. : 0.;
         }
         if (val instanceof String) {
             return parseDouble((String) val);
         }
         if (val instanceof Character) {
             return ((Character) val);
         }
         if (val == null) {
             return controlNullOperand(strict, 0.d);
         }
         throw new ArithmeticException("Double coercion: "
                 + val.getClass().getName() + ":(" + val + ")");
     }
 
     /**
      * Coerce to a string.
      * <p>Double.NaN coerce to the empty string.</p>
      *
      * @param strict true if the calling operator or casting is strict, false otherwise
      * @param val value to coerce.
      * @return The String coerced value.
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      * @since 3.3
      */
     protected String toString(final boolean strict, final Object val) {
         return isNullOperand(val)? controlNullOperand(strict, "") : toString(val);
     }
 
     /**
      * Coerce to a string.
      * <p>Double.NaN coerce to the empty string.</p>
      *
      * @param val value to coerce.
      * @return The String coerced value.
      * @throws ArithmeticException if val is null and mode is strict or if coercion is not possible
      */
     public String toString(final Object val) {
         if (val instanceof Double) {
             final Double dval = (Double) val;
             if (Double.isNaN(dval)) {
                 return "";
             }
             return dval.toString();
         }
         return val == null? controlNullOperand(strict, "") : val.toString();
     }
 
     /**
      * Checks whether this JexlArithmetic instance
      * strictly considers null as an error when used as operand unexpectedly.
      *
      * @return true if strict, false if lenient
      */
     public boolean isStrict() {
         return strict;
     }
 
     /**
      * Checks whether this arithmetic considers a given operator as strict or null-safe.
      * <p>When an operator is strict, it does <em>not</em> accept null arguments when the arithmetic is strict.
      * If null-safe (ie not-strict), the operator does accept null arguments even if the arithmetic itself is strict.</p>
      * <p>The default implementation considers equal/not-equal operators as null-safe so one can check for null as in
      * <code>if (myvar == null) {...}</code>. Note that this operator is used for equal and not-equal syntax. The complete
      * list of operators that are not strict are (==, [], []=, ., .=, empty, size, contains). </p>
      * <p>An arithmetic refining its strict behavior handling for more operators must declare which by overriding
      * this method.</p>
      * @param operator the operator to check for null-argument(s) handling
      * @return true if operator considers null arguments as errors, false if operator has appropriate semantics
      * for null argument(s)
      */
     public boolean isStrict(final JexlOperator operator) {
         if (operator != null) {
             switch (operator) {
                 case EQ:
                 case ARRAY_GET:
                 case ARRAY_SET:
                 case PROPERTY_GET:
                 case PROPERTY_SET:
                 case EMPTY:
                 case SIZE:
                 case CONTAINS:
                     return false;
                 default:
                     return isStrict();
             }
         }
         return isStrict();
     }
 
     /**
      * The MathContext instance used for +,-,/,*,% operations on big decimals.
      *
      * @return the math context
      */
     public MathContext getMathContext() {
         return mathContext;
     }
 
     /**
      * The BigDecimal scale used for comparison and coericion operations.
      *
      * @return the scale
      */
     public int getMathScale() {
         return mathScale;
     }
 
     /**
      * Ensure a big decimal is rounded by this arithmetic scale and rounding mode.
      *
      * @param number the big decimal to round
      * @return the rounded big decimal
      */
     protected BigDecimal roundBigDecimal(final BigDecimal number) {
         final int mscale = getMathScale();
         if (mscale >= 0) {
             return number.setScale(mscale, getMathContext().getRoundingMode());
         }
         return number;
     }
 
     /**
      * The result of +,/,-,*,% when both operands are null.
      *
      * @return Integer(0) if lenient
      * @throws JexlArithmetic.NullOperand if strict
      * @deprecated 3.3
      */
     @Deprecated
     protected Object controlNullNullOperands() {
         if (isStrict()) {
             throw new NullOperand();
         }
         return 0;
     }
 
     /**
      * Throws an NullOperand exception if arithmetic is strict-cast.
      *
      * @throws  JexlArithmetic.NullOperand if strict
      * @deprecated 3.3
      */
     @Deprecated
     protected void controlNullOperand() {
         if (isStrict()) {
             throw new NullOperand();
         }
     }
 
     /**
      * The float regular expression pattern.
      * <p>
      * The decimal and exponent parts are optional and captured allowing to determine if the number is a real
      * by checking whether one of these 2 capturing groups is not empty.
      */
     public static final Pattern FLOAT_PATTERN = Pattern.compile("^[+-]?\\d*(\\.\\d*)?([eE][+-]?\\d+)?$");
 
     /**
      * Test if the passed value is a floating point number, i.e. a float, double
      * or string with ( "." | "E" | "e").
      *
      * @param val the object to be tested
      * @return true if it is, false otherwise.
      */
     protected boolean isFloatingPointNumber(final Object val) {
         if (val instanceof Float || val instanceof Double) {
             return true;
         }
         if (val instanceof CharSequence) {
             final Matcher m = FLOAT_PATTERN.matcher((CharSequence) val);
             // first group is decimal, second is exponent;
             // one of them must exist hence start({1,2}) >= 0
             return m.matches() && (m.start(1) >= 0 || m.start(2) >= 0);
         }
         return false;
     }
 
     /**
      * Is Object a floating point number.
      *
      * @param o Object to be analyzed.
      * @return true if it is a Float or a Double.
      */
     protected boolean isFloatingPoint(final Object o) {
         return o instanceof Float || o instanceof Double;
     }
 
     /**
      * Is Object a whole number.
      *
      * @param o Object to be analyzed.
      * @return true if Integer, Long, Byte, Short or Character.
      */
     protected boolean isNumberable(final Object o) {
         return o instanceof Integer
                 || o instanceof Long
                 || o instanceof Byte
                 || o instanceof Short
                 || o instanceof Character;
     }
 
     /**
      * The last method called before returning a result from a script execution.
      * @param returned the returned value
      * @return the controlled returned value
      */
     public Object controlReturn(final Object returned) {
         return returned;
     }
 
     /**
      * Given a Number, return the value using the smallest type the result
      * will fit into.
      * <p>This works hand in hand with parameter 'widening' in java
      * method calls, e.g. a call to substring(int,int) with an int and a long
      * will fail, but a call to substring(int,int) with an int and a short will
      * succeed.</p>
      *
      * @param original the original number.
      * @return a value of the smallest type the original number will fit into.
      */
     public Number narrow(final Number original) {
         return narrowNumber(original, null);
     }
 
     /**
      * Whether we consider the narrow class as a potential candidate for narrowing the source.
      *
      * @param narrow the target narrow class
      * @param source the original source class
      * @return true if attempt to narrow source to target is accepted
      */
     protected boolean narrowAccept(final Class<?> narrow, final Class<?> source) {
         return narrow == null || narrow.equals(source);
     }
 
     /**
      * Given a Number, return the value attempting to narrow it to a target class.
      *
      * @param original the original number
      * @param narrow   the attempted target class
      * @return the narrowed number or the source if no narrowing was possible
      */
     public Number narrowNumber(final Number original, final Class<?> narrow) {
         if (original == null) {
             return null;
         }
         Number result = original;
         if (original instanceof BigDecimal) {
             final BigDecimal bigd = (BigDecimal) original;
             // if it is bigger than a double, it can not be narrowed
             if (bigd.compareTo(BIGD_DOUBLE_MAX_VALUE) > 0
                 || bigd.compareTo(BIGD_DOUBLE_MIN_VALUE) < 0) {
                 return original;
             }
             try {
                 final long l = bigd.longValueExact();
                 // coerce to int when possible (int being so often used in method parms)
                 if (narrowAccept(narrow, Integer.class)
                         && l <= Integer.MAX_VALUE
                         && l >= Integer.MIN_VALUE) {
                     return (int) l;
                 }
                 if (narrowAccept(narrow, Long.class)) {
                     return l;
                 }
             } catch (final ArithmeticException xa) {
                 // ignore, no exact value possible
             }
         }
         if (original instanceof Double || original instanceof Float) {
             final double value = original.doubleValue();
             if (narrowAccept(narrow, Float.class)
                     && value <= Float.MAX_VALUE
                     && value >= Float.MIN_VALUE) {
                 result = result.floatValue();
             }
             // else it fits in a double only
         } else {
             if (original instanceof BigInteger) {
                 final BigInteger bigi = (BigInteger) original;
                 // if it is bigger than a Long, it can not be narrowed
                 if (bigi.compareTo(BIGI_LONG_MAX_VALUE) > 0
                         || bigi.compareTo(BIGI_LONG_MIN_VALUE) < 0) {
                     return original;
                 }
             }
             final long value = original.longValue();
             if (narrowAccept(narrow, Byte.class)
                     && value <= Byte.MAX_VALUE
                     && value >= Byte.MIN_VALUE) {
                 // it will fit in a byte
                 result = (byte) value;
             } else if (narrowAccept(narrow, Short.class)
                     && value <= Short.MAX_VALUE
                     && value >= Short.MIN_VALUE) {
                 result = (short) value;
             } else if (narrowAccept(narrow, Integer.class)
                     && value <= Integer.MAX_VALUE
                     && value >= Integer.MIN_VALUE) {
                 result = (int) value;
             }
             // else it fits in a long
         }
         return result;
     }
 
     /**
      * Given a BigInteger, narrow it to an Integer or Long if it fits and the arguments
      * class allow it.
      * <p>
      * The rules are:
      * if either arguments is a BigInteger, no narrowing will occur
      * if either arguments is a Long, no narrowing to Integer will occur
      * </p>
      *
      * @param lhs  the left-hand side operand that lead to the bigi result
      * @param rhs  the right-hand side operand that lead to the bigi result
      * @param bigi the BigInteger to narrow
      * @return an Integer or Long if narrowing is possible, the original BigInteger otherwise
      */
     protected Number narrowBigInteger(final Object lhs, final Object rhs, final BigInteger bigi) {
         //coerce to long if possible
         if ((isNumberable(lhs) || isNumberable(rhs))
                 && bigi.compareTo(BIGI_LONG_MAX_VALUE) <= 0
                 && bigi.compareTo(BIGI_LONG_MIN_VALUE) >= 0) {
             // coerce to int if possible
             final long l = bigi.longValue();
             // coerce to int when possible (int being so often used in method parms)
             if (!(lhs instanceof Long || rhs instanceof Long)
                     && l <= Integer.MAX_VALUE
                     && l >= Integer.MIN_VALUE) {
                 return (int) l;
             }
             return l;
         }
         return bigi;
     }
 
     /**
      * Given a BigDecimal, attempt to narrow it to an Integer or Long if it fits and
      * one of the arguments is a numberable.
      *
      * @param lhs  the left-hand side operand that lead to the bigd result
      * @param rhs  the right-hand side operand that lead to the bigd result
      * @param bigd the BigDecimal to narrow
      * @return an Integer or Long if narrowing is possible, the original BigDecimal otherwise
      */
     protected Number narrowBigDecimal(final Object lhs, final Object rhs, final BigDecimal bigd) {
         if (isNumberable(lhs) || isNumberable(rhs)) {
             try {
                 final long l = bigd.longValueExact();
                 // coerce to int when possible (int being so often used in method parms)
                 if (l <= Integer.MAX_VALUE && l >= Integer.MIN_VALUE) {
                     return (int) l;
                 }
                 return l;
             } catch (final ArithmeticException xa) {
                 // ignore, no exact value possible
             }
         }
         return bigd;
     }
 
     /**
      * Replace all numbers in an arguments array with the smallest type that will fit.
      *
      * @param args the argument array
      * @return true if some arguments were narrowed and args array is modified,
      *         false if no narrowing occurred and args array has not been modified
      */
     public boolean narrowArguments(final Object[] args) {
         boolean narrowed = false;
         if (args != null) {
             for (int a = 0; a < args.length; ++a) {
                 final Object arg = args[a];
                 if (arg instanceof Number) {
                     final Number narg = (Number) arg;
                     final Number narrow = narrow(narg);
                     if (!narg.equals(narrow)) {
                         args[a] = narrow;
                         narrowed = true;
                     }
                 }
             }
         }
         return narrowed;
     }
 
     /**
      * Given a long, attempt to narrow it to an int.
      * <p>Narrowing will only occur if no operand is a Long.
      * @param lhs  the left hand side operand that lead to the long result
      * @param rhs  the right hand side operand that lead to the long result
      * @param r the long to narrow
      * @return an Integer if narrowing is possible, the original Long otherwise
      */
     protected Number narrowLong(final Object lhs, final Object rhs, final long r) {
         if (!(lhs instanceof Long || rhs instanceof Long) && (int) r == r) {
             return (int) r;
         }
         return r;
     }
 
     /**
      * Checks if value class is a number that can be represented exactly in a long.
      *
      * @param value  argument
      * @return true if argument can be represented by a long
      */
     protected Number asLongNumber(final Object value) {
         return value instanceof Long
                 || value instanceof Integer
                 || value instanceof Short
                 || value instanceof Byte
                         ? (Number) value
                         : null;
     }
 
     /**
      * Increments argument by 1.
      * @param val the argument
      * @return val + 1
      */
     public Object increment(final Object val) {
         return increment(val, 1);
     }
 
     /**
      * Decrements argument by 1.
      * @param val the argument
      * @return val - 1
      */
     public Object decrement(final Object val) {
         return increment(val, -1);
     }
 
     /**
      * Add value to number argument.
      * @param val the number
      * @param incr the value to add
      * @return val + incr
      */
     protected Object increment(final Object val, final int incr) {
         if (val == null) {
             return incr;
         }
         if (val instanceof Integer) {
             return ((Integer) val) + incr;
         }
         if (val instanceof Double) {
             return ((Double) val) + incr;
         }
         if (val instanceof Long) {
             return ((Long) val) + incr;
         }
         if (val instanceof BigDecimal) {
             final BigDecimal bd = (BigDecimal) val;
             return bd.add(BigDecimal.valueOf(incr), this.mathContext);
         }
         if (val instanceof BigInteger) {
             final BigInteger bi = (BigInteger) val;
             return bi.add(BigInteger.valueOf(incr));
         }
         if (val instanceof Float) {
             return ((Float) val) + incr;
         }
         if (val instanceof Short) {
             return (short) (((Short) val) + incr);
         }
         if (val instanceof Byte) {
             return (byte) (((Byte) val) + incr);
         }
         throw new ArithmeticException("Object "+(incr < 0? "decrement":"increment")+":(" + val + ")");
     }
 
     /**
      * Add two values together.
      * <p>
      * If any numeric add fails on coercion to the appropriate type,
      * treat as Strings and do concatenation.
      * </p>
      *
      * @param left  left argument
      * @param right  right argument
      * @return left + right.
      */
     public Object add(final Object left, final Object right) {
         if (left == null && right == null) {
             return controlNullNullOperands(JexlOperator.ADD);
         }
         final boolean strconcat = strict
                             ? left instanceof String || right instanceof String
                             : left instanceof String && right instanceof String;
         if (!strconcat) {
             try {
                 // if both (non-null) args fit as long
                 final Number ln = asLongNumber(left);
                 final Number rn = asLongNumber(right);
                 if (ln != null && rn != null) {
                     final long x = ln.longValue();
                     final long y = rn.longValue();
                     final long result = x + y;
                     // detect overflow, see java8 Math.addExact
                     if (((x ^ result) & (y ^ result)) < 0) {
                         return BigInteger.valueOf(x).add(BigInteger.valueOf(y));
                     }
                     return narrowLong(left, right, result);
                 }
                 final boolean strictCast = isStrict(JexlOperator.ADD);
                 // if either are bigdecimal use that type
                 if (left instanceof BigDecimal || right instanceof BigDecimal) {
                     final BigDecimal l = toBigDecimal(strictCast, left);
                     final BigDecimal r = toBigDecimal(strictCast, right);
                     final BigDecimal result = l.add(r, getMathContext());
                     return narrowBigDecimal(left, right, result);
                 }
                 // if either are floating point (double or float) use double
                 if (isFloatingPointNumber(left) || isFloatingPointNumber(right)) {
                     final double l = toDouble(strictCast, left);
                     final double r = toDouble(strictCast, right);
                     return l + r;
                 }
                 // otherwise treat as (big) integers
                 final BigInteger l = toBigInteger(strictCast, left);
                 final BigInteger r = toBigInteger(strictCast, right);
                 final BigInteger result = l.add(r);
                 return narrowBigInteger(left, right, result);
             } catch (final ArithmeticException nfe) {
                 // ignore and continue in sequence
             }
         }
         return (left == null? "" : toString(left)).concat(right == null ? "" : toString(right));
     }
 
     /**
      * Divide the left value by the right.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left / right
      * @throws ArithmeticException if right == 0
      */
     public Object divide(final Object left, final Object right) {
         if (left == null && right == null) {
             return controlNullNullOperands(JexlOperator.DIVIDE);
         }
         // if both (non-null) args fit as long
         final Number ln = asLongNumber(left);
         final Number rn = asLongNumber(right);
         if (ln != null && rn != null) {
             final long x = ln.longValue();
             final long y = rn.longValue();
             if (y == 0L) {
                 throw new ArithmeticException("/");
             }
             final long result = x  / y;
             return narrowLong(left, right, result);
         }
         final boolean strictCast = isStrict(JexlOperator.DIVIDE);
         // if either are bigdecimal use that type
         if (left instanceof BigDecimal || right instanceof BigDecimal) {
             final BigDecimal l = toBigDecimal(strictCast, left);
             final BigDecimal r = toBigDecimal(strictCast, right);
             if (BigDecimal.ZERO.equals(r)) {
                 throw new ArithmeticException("/");
             }
             final BigDecimal result = l.divide(r, getMathContext());
             return narrowBigDecimal(left, right, result);
         }
         // if either are floating point (double or float) use double
         if (isFloatingPointNumber(left) || isFloatingPointNumber(right)) {
             final double l = toDouble(strictCast, left);
             final double r = toDouble(strictCast, right);
             if (r == 0.0) {
                 throw new ArithmeticException("/");
             }
             return l / r;
         }
         // otherwise treat as integers
         final BigInteger l = toBigInteger(strictCast, left);
         final BigInteger r = toBigInteger(strictCast, right);
         if (BigInteger.ZERO.equals(r)) {
             throw new ArithmeticException("/");
         }
         final BigInteger result = l.divide(r);
         return narrowBigInteger(left, right, result);
     }
 
     /**
      * left value modulo right.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left % right
      * @throws ArithmeticException if right == 0.0
      */
     public Object mod(final Object left, final Object right) {
         if (left == null && right == null) {
             return controlNullNullOperands(JexlOperator.MOD);
         }
         // if both (non-null) args fit as long
         final Number ln = asLongNumber(left);
         final Number rn = asLongNumber(right);
         if (ln != null && rn != null) {
             final long x = ln.longValue();
             final long y = rn.longValue();
             if (y == 0L) {
                 throw new ArithmeticException("%");
             }
             final long result = x % y;
             return narrowLong(left, right,  result);
         }
         final boolean strictCast = isStrict(JexlOperator.MOD);
         // if either are bigdecimal use that type
         if (left instanceof BigDecimal || right instanceof BigDecimal) {
             final BigDecimal l = toBigDecimal(strictCast, left);
             final BigDecimal r = toBigDecimal(strictCast, right);
             if (BigDecimal.ZERO.equals(r)) {
                 throw new ArithmeticException("%");
             }
             final BigDecimal remainder = l.remainder(r, getMathContext());
             return narrowBigDecimal(left, right, remainder);
         }
         // if either are floating point (double or float) use double
         if (isFloatingPointNumber(left) || isFloatingPointNumber(right)) {
             final double l = toDouble(strictCast, left);
             final double r = toDouble(strictCast, right);
             if (r == 0.0) {
                 throw new ArithmeticException("%");
             }
             return l % r;
         }
         // otherwise treat as integers
         final BigInteger l = toBigInteger(strictCast, left);
         final BigInteger r = toBigInteger(strictCast, right);
         if (BigInteger.ZERO.equals(r)) {
             throw new ArithmeticException("%");
         }
         final BigInteger result = l.mod(r);
         return narrowBigInteger(left, right, result);
     }
 
     /**
      * Checks if the product of the arguments overflows a {@code long}.
      * <p>see java8 Math.multiplyExact
      * @param x the first value
      * @param y the second value
      * @param r the product
      * @return true if product fits a long, false if it overflows
      */
     @SuppressWarnings("MagicNumber")
     protected static boolean isMultiplyExact(final long x, final long y, final long r) {
         final long ax = Math.abs(x);
         final long ay = Math.abs(y);
         return !(((ax | ay) >>> (Integer.SIZE - 1) != 0)
                   && (((y != 0) && (r / y != x))
                       || (x == Long.MIN_VALUE && y == -1)));
     }
 
     /**
      * Multiply the left value by the right.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left * right.
      */
     public Object multiply(final Object left, final Object right) {
         if (left == null && right == null) {
             return controlNullNullOperands(JexlOperator.MULTIPLY);
         }
         // if both (non-null) args fit as int
         final Number ln = asLongNumber(left);
         final Number rn = asLongNumber(right);
         if (ln != null && rn != null) {
             final long x = ln.longValue();
             final long y = rn.longValue();
             final long result = x * y;
             // detect overflow
             if (!isMultiplyExact(x, y, result)) {
                 return BigInteger.valueOf(x).multiply(BigInteger.valueOf(y));
             }
             return narrowLong(left, right, result);
         }
         final boolean strictCast = isStrict(JexlOperator.MULTIPLY);
         // if either are bigdecimal use that type
         if (left instanceof BigDecimal || right instanceof BigDecimal) {
             final BigDecimal l = toBigDecimal(strictCast, left);
             final BigDecimal r = toBigDecimal(strictCast, right);
             final BigDecimal result = l.multiply(r, getMathContext());
             return narrowBigDecimal(left, right, result);
         }
         // if either are floating point (double or float) use double
         if (isFloatingPointNumber(left) || isFloatingPointNumber(right)) {
             final double l = toDouble(strictCast, left);
             final double r = toDouble(strictCast, right);
             return l * r;
         }
         // otherwise treat as integers
         final BigInteger l = toBigInteger(strictCast, left);
         final BigInteger r = toBigInteger(strictCast, right);
         final BigInteger result = l.multiply(r);
         return narrowBigInteger(left, right, result);
     }
 
     /**
      * Subtract the right value from the left.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left - right.
      */
     public Object subtract(final Object left, final Object right) {
         if (left == null && right == null) {
             return controlNullNullOperands(JexlOperator.SUBTRACT);
         }
         // if both (non-null) args fit as long
         final Number ln = asLongNumber(left);
         final Number rn = asLongNumber(right);
         if (ln != null && rn != null) {
             final long x = ln.longValue();
             final long y = rn.longValue();
             final long result = x - y;
             // detect overflow, see java8 Math.subtractExact
             if (((x ^ y) & (x ^ result)) < 0) {
                 return BigInteger.valueOf(x).subtract(BigInteger.valueOf(y));
             }
             return narrowLong(left, right, result);
         }
         final boolean strictCast = isStrict(JexlOperator.SUBTRACT);
         // if either are bigdecimal use that type
         if (left instanceof BigDecimal || right instanceof BigDecimal) {
             final BigDecimal l = toBigDecimal(strictCast, left);
             final BigDecimal r = toBigDecimal(strictCast, right);
             final BigDecimal result = l.subtract(r, getMathContext());
             return narrowBigDecimal(left, right, result);
         }
         // if either are floating point (double or float) use double
         if (isFloatingPointNumber(left) || isFloatingPointNumber(right)) {
             final double l = toDouble(strictCast, left);
             final double r = toDouble(strictCast, right);
             return l - r;
         }
         // otherwise treat as integers
         final BigInteger l = toBigInteger(strictCast, left);
         final BigInteger r = toBigInteger(strictCast, right);
         final BigInteger result = l.subtract(r);
         return narrowBigInteger(left, right, result);
     }
 
     /**
      * Negates a value (unary minus for numbers).
      *
      * @see #isNegateStable()
      * @param val the value to negate
      * @return the negated value
      */
     public Object negate(final Object val) {
         if (val == null) {
             return null;
         }
         if (val instanceof Integer) {
             return -((Integer) val);
         }
         if (val instanceof Double) {
             return - ((Double) val);
         }
         if (val instanceof Long) {
             return -((Long) val);
         }
         if (val instanceof BigDecimal) {
             return ((BigDecimal) val).negate();
         }
         if (val instanceof BigInteger) {
             return ((BigInteger) val).negate();
         }
         if (val instanceof Float) {
             return -((Float) val);
         }
         if (val instanceof Short) {
             return (short) -((Short) val);
         }
         if (val instanceof Byte) {
             return (byte) -((Byte) val);
         }
         if (val instanceof Boolean) {
             return !(Boolean) val;
         }
         if (val instanceof AtomicBoolean) {
             return !((AtomicBoolean) val).get();
         }
         throw new ArithmeticException("Object negate:(" + val + ")");
     }
 
     /**
      * Whether negate called with a given argument will always return the same result.
      * <p>This is used to determine whether negate results on number literals can be cached.
      * If the result on calling negate with the same constant argument may change between calls,
      * which means the function is not deterministic, this method must return false.
      * @return true if negate is idempotent, false otherwise
      */
     public boolean isNegateStable() {
         return true;
     }
 
     /**
      * Positivize value (unary plus for numbers).
      * <p>C/C++/C#/Java perform integral promotion of the operand, ie
      * cast to int if type can be represented as int without loss of precision.
      * @see #isPositivizeStable()
      * @param val the value to positivize
      * @return the positive value
      */
     public Object positivize(final Object val) {
         if (val == null) {
             return null;
         }
         if (val instanceof Short) {
             return ((Short) val).intValue();
         }
         if (val instanceof Byte) {
             return ((Byte) val).intValue();
         }
         if (val instanceof Number) {
             return val;
         }
         if (val instanceof Character) {
             return (int) (Character) val;
         }
         if (val instanceof Boolean) {
             return val;
         }
         if (val instanceof AtomicBoolean) {
             return ((AtomicBoolean) val).get();
         }
         throw new ArithmeticException("Object positivize:(" + val + ")");
     }
 
     /**
      * Whether positivize called with a given argument will always return the same result.
      * <p>This is used to determine whether positivize results on number literals can be cached.
      * If the result on calling positivize with the same constant argument may change between calls,
      * which means the function is not deterministic, this method must return false.
      * @return true if positivize is idempotent, false otherwise
      */
     public boolean isPositivizeStable() {
         return true;
     }
 
     /**
      * Test if a condition is true or false.
      * @param object the object to use as condition
      * @return true or false
      * @since 3.3
      */
     public boolean testPredicate(final Object object) {
         final boolean strictCast = isStrict(JexlOperator.CONDITION);
         return toBoolean(strictCast, object);
     }
 
     /**
      * Test if left contains right (right matches/in left).
      * <p>Beware that this &quot;contains &quot; method arguments order is the opposite of the
      * &quot;in/matches&quot; operator arguments.
      * <code>x =~ y</code> means <code>y contains x</code> thus <code>contains(x, y)</code>.</p>
      * <p>When this method returns null during evaluation, the operator code continues trying to find
      * one through the uberspect.</p>
      * @param container the container
      * @param value the value
      * @return test result or null if there is no arithmetic solution
      */
     public Boolean contains(final Object container, final Object value) {
         if (value == null && container == null) {
             //if both are null L == R
             return true;
         }
         if (value == null || container == null) {
             // we know both aren't null, therefore L != R
             return false;
         }
         // use arithmetic / pattern matching ?
         if (container instanceof java.util.regex.Pattern) {
             return ((java.util.regex.Pattern) container).matcher(value.toString()).matches();
         }
         if (container instanceof CharSequence) {
             return value.toString().matches(container.toString());
         }
         // try contains on map key
         if (container instanceof Map<?, ?>) {
             if (value instanceof Map<?, ?>) {
                 return ((Map<?, ?>) container).keySet().containsAll(((Map<?, ?>) value).keySet());
             }
             return ((Map<?, ?>) container).containsKey(value);
         }
         // try contains on collection
         return collectionContains(container, value);
     }
 
     /**
      * Checks whether a potential collection contains another.
      * <p>Made protected to make it easier to override if needed.</p>
      * @param collection the container which can be a collection or an array (even of primitive)
      * @param value the value which can be a collection or an array (even of primitive) or a singleton
      * @return test result or null if there is no arithmetic solution
      */
     protected Boolean collectionContains(final Object collection, final Object value) {
         // convert arrays if needed
         final Object left = arrayWrap(collection);
         if (left instanceof Collection<?>) {
             final Object right = arrayWrap(value);
             if (right instanceof Collection<?>) {
                 return ((Collection<?>) left).containsAll((Collection<?>) right);
             }
             return ((Collection<?>) left).contains(value);
         }
         return null;
     }
 
     /**
      * Attempts transformation of potential array in an abstract list or leave as is.
      * <p>An array (as in int[]) is not convenient to call methods so when encountered we turn them into lists</p>
      * @param container an array or on object
      * @return an abstract list wrapping the array instance or the initial argument
      * @see org.apache.commons.jexl3.internal.introspection.ArrayListWrapper
      */
     private static Object arrayWrap(final Object container) {
         return container.getClass().isArray()
                 ? new org.apache.commons.jexl3.internal.introspection.ArrayListWrapper(container)
                 : container;
     }
 
     /**
      * Test if left ends with right.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left $= right if there is no arithmetic solution
      */
     public Boolean endsWith(final Object left, final Object right) {
         if (left == null && right == null) {
             //if both are null L == R
             return true;
         }
         if (left == null || right == null) {
             // we know both aren't null, therefore L != R
             return false;
         }
         if (left instanceof CharSequence) {
             return (toString(left)).endsWith(toString(right));
         }
         return null;
     }
 
     /**
      * Test if left starts with right.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left ^= right or null if there is no arithmetic solution
      */
     public Boolean startsWith(final Object left, final Object right) {
         if (left == null && right == null) {
             //if both are null L == R
             return true;
         }
         if (left == null || right == null) {
             // we know both aren't null, therefore L != R
             return false;
         }
         if (left instanceof CharSequence) {
             return (toString(left)).startsWith(toString(right));
         }
         return null;
     }
 
     /**
      * Check for emptiness of various types: Number, Collection, Array, Map, String.
      * <p>Override or overload this method to add new signatures to the size operators.
      * @param object the object to check the emptiness of
      * @return the boolean or false if object is not null
      * @since 3.2
      */
     public Boolean empty(final Object object) {
         return object == null || isEmpty(object, false);
     }
 
     /**
      * Check for emptiness of various types: Number, Collection, Array, Map, String.
      *
      * @param object the object to check the emptiness of
      * @return the boolean or null if there is no arithmetic solution
      */
     public Boolean isEmpty(final Object object) {
         return isEmpty(object, object == null);
     }
 
     /**
      * Check for emptiness of various types: Number, Collection, Array, Map, String.
      *
      * @param object the object to check the emptiness of
      * @param def the default value if object emptyness can not be determined
      * @return the boolean or null if there is no arithmetic solution
      */
     public Boolean isEmpty(final Object object, final Boolean def) {
         if (object != null) {
             if (object instanceof Number) {
                 final double d = ((Number) object).doubleValue();
                 return Double.isNaN(d) || d == 0.d;
             }
             if (object instanceof CharSequence) {
                 return ((CharSequence) object).length() == 0;
             }
             if (object.getClass().isArray()) {
                 return Array.getLength(object) == 0;
             }
             if (object instanceof Collection<?>) {
                 return ((Collection<?>) object).isEmpty();
             }
             // Map isn't a collection
             if (object instanceof Map<?, ?>) {
                 return ((Map<?, ?>) object).isEmpty();
             }
         }
         return def;
     }
 
     /**
      * Calculate the <code>size</code> of various types: Collection, Array, Map, String.
      *
      * @param object the object to get the size of
      * @return the <i>size</i> of object, 0 if null, 1 if there is no <i>better</i> solution
      */
     public Integer size(final Object object) {
         return size(object, object == null? 0 : 1);
     }
 
     /**
      * Calculate the <code>size</code> of various types: Collection, Array, Map, String.
      *
      * @param object the object to get the size of
      * @param def the default value if object size can not be determined
      * @return the size of object or null if there is no arithmetic solution
      */
     public Integer size(final Object object, final Integer def) {
         if (object instanceof CharSequence) {
             return ((CharSequence) object).length();
         }
         if (object.getClass().isArray()) {
             return Array.getLength(object);
         }
         if (object instanceof Collection<?>) {
             return ((Collection<?>) object).size();
         }
         if (object instanceof Map<?, ?>) {
             return ((Map<?, ?>) object).size();
         }
         return def;
     }
 
     /**
      * Performs a bitwise and.
      *
      * @param left  the left operand
      * @param right the right operator
      * @return left &amp; right
      */
     public Object and(final Object left, final Object right) {
         final long l = toLong(left);
         final long r = toLong(right);
         return l & r;
     }
 
     /**
      * Performs a bitwise or.
      *
      * @param left  the left operand
      * @param right the right operator
      * @return left | right
      */
     public Object or(final Object left, final Object right) {
         final long l = toLong(left);
         final long r = toLong(right);
         return l | r;
     }
 
     /**
      * Performs a bitwise xor.
      *
      * @param left  the left operand
      * @param right the right operator
      * @return left ^ right
      */
     public Object xor(final Object left, final Object right) {
         final long l = toLong(left);
         final long r = toLong(right);
         return l ^ r;
     }
 
     /**
      * Performs a bitwise complement.
      *
      * @param val the operand
      * @return ~val
      */
     public Object complement(final Object val) {
         final boolean strictCast = isStrict(JexlOperator.COMPLEMENT);
         final long l = toLong(strictCast, val);
         return ~l;
     }
 
     /**
      * Performs a logical not.
      *
      * @param val the operand
      * @return !val
      */
     public Object not(final Object val) {
         final boolean strictCast = isStrict(JexlOperator.NOT);
         return !toBoolean(strictCast, val);
     }
 
     /**
      * Shifts a bit pattern to the right.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left &lt;&lt; right.
      */
     public Object shiftLeft(final Object left, final Object right) {
         final long l = toLong(left);
         final int r = toInteger(right);
         return l << r;
     }
 
     /**
      * Shifts a bit pattern to the right.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left &gt;&gt; right.
      */
     public Object shiftRight(final Object left, final Object right) {
         final long l = toLong(left);
         final long r = toInteger(right);
         return l >> r;
     }
 
     /**
      * Shifts a bit pattern to the right unsigned.
      *
      * @param left  left argument
      * @param right  right argument
      * @return left &gt;&gt;&gt; right.
      */
     public Object shiftRightUnsigned(final Object left, final Object right) {
         final long l = toLong(left);
         final long r = toInteger(right);
         return l >>> r;
     }
 
     /**
      * Any override of this method (pre 3.3) should be modified to match the new signature.
      * @param left left operand
      * @param right right operand
      * @param symbol the operator symbol
      * @return -1 if left &lt; right; +1 if left &gt; right; 0 if left == right
      * {@link JexlArithmetic#compare(Object, Object, JexlOperator)}
      * @deprecated 3.3
      */
     @Deprecated
     protected int compare(final Object left, final Object right, final String symbol) {
         JexlOperator operator;
         try {
             operator = JexlOperator.valueOf(symbol);
         } catch (final IllegalArgumentException xill) {
             // ignore
             operator = JexlOperator.EQ;
         }
         return doCompare(left, right, operator);
     }
 
     /**
      * Determines if the compare method(Object, Object, String) is overriden in this class or one of its
      * superclasses.
      */
     private final boolean compare321 = computeCompare321(this);
     private static boolean computeCompare321(final JexlArithmetic arithmetic) {
         Class<?> arithmeticClass = arithmetic.getClass();
         while(arithmeticClass != JexlArithmetic.class) {
             try {
                 Method cmp = arithmeticClass.getDeclaredMethod("compare", Object.class, Object.class, String.class);
                if (cmp.getDeclaringClass() != JexlArithmetic.class) {
                    return true;
                }
             } catch (NoSuchMethodException xany) {
                 arithmeticClass = arithmeticClass.getSuperclass();
             }
         }
         return false;
     }
 
     /**
      * Performs a comparison.
      *
      * @param left     the left operand
      * @param right    the right operator
      * @param operator the operator
      * @return -1 if left &lt; right; +1 if left &gt; right; 0 if left == right
      * @throws ArithmeticException if either left or right is null
      */
     protected int compare(final Object left, final Object right, final JexlOperator operator) {
         // this is a temporary way of allowing pre-3.3 code that overrode compare() to still call
         // the user method. This method will merge with doCompare in 3.4 and the compare321 flag will disappear.
         return compare321
                 ? compare(left, right, operator.toString())
                 : doCompare(left, right, operator);
     }
 
     private int doCompare(final Object left, final Object right, final JexlOperator operator) {
         final boolean strictCast = isStrict(operator);
         if (left != null && right != null) {
             if (left instanceof BigDecimal || right instanceof BigDecimal) {
                 final BigDecimal l = toBigDecimal(strictCast, left);
                 final BigDecimal r = toBigDecimal(strictCast, right);
                 return l.compareTo(r);
             }
             if (left instanceof BigInteger || right instanceof BigInteger) {
                 try {
                     final BigInteger l = toBigInteger(strictCast, left);
                     final BigInteger r = toBigInteger(strictCast, right);
                     return l.compareTo(r);
                 } catch (final ArithmeticException xconvert) {
                     // ignore it, continue in sequence
                 }
             }
             if (isFloatingPoint(left) || isFloatingPoint(right)) {
                 final double lhs = toDouble(strictCast, left);
                 final double rhs = toDouble(strictCast, right);
                 if (Double.isNaN(lhs)) {
                     if (Double.isNaN(rhs)) {
                         return 0;
                     }
                     return -1;
                 }
                 if (Double.isNaN(rhs)) {
                     // lhs is not NaN
                     return +1;
                 }
                 return Double.compare(lhs, rhs);
             }
             if (isNumberable(left) || isNumberable(right)) {
                 try {
                     final long lhs = toLong(strictCast, left);
                     final long rhs = toLong(strictCast, right);
                     return Long.compare(lhs, rhs);
                 } catch (final ArithmeticException xconvert) {
                     // ignore it, continue in sequence
                 }
             }
             if (left instanceof String || right instanceof String) {
                 return toString(left).compareTo(toString(right));
             }
             if (JexlOperator.EQ == operator) {
                 return left.equals(right) ? 0 : -1;
             }
             if (left instanceof Comparable<?>) {
                 @SuppressWarnings("unchecked") // OK because of instanceof check above
                 final Comparable<Object> comparable = (Comparable<Object>) left;
                 return comparable.compareTo(right);
             }
         }
         throw new ArithmeticException("Object comparison:(" + left + " " + operator + " " + right + ")");
     }
 
     /**
      * Test if left and right are equal.
      *
      * @param left  left argument
      * @param right right argument
      * @return the test result
      */
     public boolean equals(final Object left, final Object right) {
         if (left == right) {
             return true;
         }
         if (left == null || right == null) {
             return false;
         }
         final boolean strictCast = isStrict(JexlOperator.EQ);
         if (left instanceof Boolean || right instanceof Boolean) {
             return toBoolean(left) == toBoolean(strictCast, right);
         }
         return compare(left, right, JexlOperator.EQ) == 0;
     }
 
     /**
      * Test if left &lt; right.
      *
      * @param left  left argument
      * @param right right argument
      * @return the test result
      */
     public boolean lessThan(final Object left, final Object right) {
         if ((left == right) || (left == null) || (right == null)) {
             return false;
         }
         return compare(left, right, JexlOperator.LT) < 0;
 
     }
 
     /**
      * Test if left &gt; right.
      *
      * @param left  left argument
      * @param right right argument
      * @return the test result
      */
     public boolean greaterThan(final Object left, final Object right) {
         if ((left == right) || left == null || right == null) {
             return false;
         }
         return compare(left, right, JexlOperator.GT) > 0;
     }
 
     /**
      * Test if left &lt;= right.
      *
      * @param left  left argument
      * @param right right argument
      * @return the test result
      */
     public boolean lessThanOrEqual(final Object left, final Object right) {
         if (left == right) {
             return true;
         }
         if (left == null || right == null) {
             return false;
         }
         return compare(left, right, JexlOperator.LTE) <= 0;
     }
 
     /**
      * Test if left &gt;= right.
      *
      * @param left  left argument
      * @param right right argument
      * @return the test result
      */
     public boolean greaterThanOrEqual(final Object left, final Object right) {
         if (left == right) {
             return true;
         }
         if (left == null || right == null) {
             return false;
         }
         return compare(left, right, JexlOperator.GTE) >= 0;
     }
 
     /**
      * Convert a string to a double.
      * <>Empty string is considered as NaN.</>
      * @param arg the arg
      * @return a double
      * @throws ArithmeticException if the string can not be coerced into a double
      */
     private double parseDouble(final String arg) throws ArithmeticException {
         try {
             return arg.isEmpty()? Double.NaN : Double.parseDouble(arg);
         } catch (final NumberFormatException e) {
             final ArithmeticException arithmeticException = new ArithmeticException("Double coercion: ("+ arg +")");
             arithmeticException.initCause(e);
             throw arithmeticException;
         }
     }
 
     /**
      * Converts a string to a long.
      * <p>This ensure the represented number is a natural (not a real).</p>
      * @param arg the arg
      * @return a long
      * @throws ArithmeticException if the string can not be coerced into a long
      */
     private long parseLong(final String arg) throws ArithmeticException {
         final double d = parseDouble(arg);
         if (Double.isNaN(d)) {
             return 0L;
         }
         final double f = floor(d);
         if (d == f) {
             return (long) d;
         }
         throw new ArithmeticException("Long coercion: ("+ arg +")");
     }
 
     /**
      * Converts a string to an int.
      * <p>This ensure the represented number is a natural (not a real).</p>
      * @param arg the arg
      * @return an int
      * @throws ArithmeticException if the string can not be coerced into a long
      */
     private int parseInteger(final String arg) throws ArithmeticException {
         final long l = parseLong(arg);
         final int i = (int) l;
         if (i == l) {
             return i;
         }
         throw new ArithmeticException("Int coercion: ("+ arg +")");
     }
 
     /**
      * Converts a string to a big integer.
      * <>Empty string is considered as 0.</>
      * @param arg the arg
      * @return a big integer
      * @throws ArithmeticException if the string can not be coerced into a big integer
      */
     private BigInteger parseBigInteger(final String arg) throws ArithmeticException {
         if (arg.isEmpty()) {
             return BigInteger.ZERO;
         }
         try {
             return new BigInteger(arg);
         } catch (final NumberFormatException xformat) {
             // ignore, try harder
         }
         return BigInteger.valueOf(parseLong(arg));
     }
 
     /**
      * Use or overload and() instead.
      * @param lhs left hand side
      * @param rhs right hand side
      * @return lhs &amp; rhs
      * @see JexlArithmetic#and
      * @deprecated 3.0
      */
     @Deprecated
     public final Object bitwiseAnd(final Object lhs, final Object rhs) {
         return and(lhs, rhs);
     }
 
     /**
      * Use or overload or() instead.
      *
      * @param lhs left hand side
      * @param rhs right hand side
      * @return lhs | rhs
      * @see JexlArithmetic#or
      * @deprecated 3.0
      */
     @Deprecated
     public final Object bitwiseOr(final Object lhs, final Object rhs) {
         return or(lhs, rhs);
     }
 
     /**
      * Use or overload xor() instead.
      *
      * @param lhs left hand side
      * @param rhs right hand side
      * @return lhs ^ rhs
      * @see JexlArithmetic#xor
      * @deprecated 3.0
      */
     @Deprecated
     public final Object bitwiseXor(final Object lhs, final Object rhs) {
         return xor(lhs, rhs);
     }
 
     /**
      * Use or overload not() instead.
      *
      * @param arg argument
      * @return !arg
      * @see JexlArithmetic#not
      * @deprecated 3.0
      */
     @Deprecated
     public final Object logicalNot(final Object arg) {
         return not(arg);
     }
 
     /**
      * Use or overload contains() instead.
      *
      * @param lhs left hand side
      * @param rhs right hand side
      * @return contains(rhs, lhs)
      * @see JexlArithmetic#contains
      * @deprecated 3.0
      */
     @Deprecated
     public final Object matches(final Object lhs, final Object rhs) {
         return contains(rhs, lhs);
     }
 }