org.expressionj.functions

Class FunctionsDefinitions

java.lang.Object

org.expressionj.functions.FunctionsDefinitions

public class FunctionsDefinitions
extends java.lang.Object

This singleton class allows to bind function names in the mathematical expressions to regular Java methods.

Method Summary

Modifier and Type	Method and Description
void	addFunction(java.lang.String name, java.lang.Object obj, java.lang.reflect.Method method) Add a new binding.
Function	getFunction(FunctionKey key) Return the function of a given key.
java.util.Map<FunctionKey,Function>	getFunctions() Return the Map of functions.
static FunctionsDefinitions	getInstance() Return the unique instance.
static boolean	isVarargs(java.lang.String functionName)
void	reset() Reset all the bindings.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static FunctionsDefinitions getInstance()

Return the unique instance.

Returns:

the unique instance

reset

public void reset()

Reset all the bindings.

getFunctions

public java.util.Map<FunctionKey,Function> getFunctions()

Return the Map of functions.

Returns:

the Map of functions

isVarargs

public static boolean isVarargs(java.lang.String functionName)

getFunction

public Function getFunction(FunctionKey key)

Return the function of a given key.

Parameters:

key - the function key

Returns:

the function

addFunction

public void addFunction(java.lang.String name,
                        java.lang.Object obj,
                        java.lang.reflect.Method method)

Add a new binding. For example, to add the new "test" function, this code is valid:

   FunctionsDefinitions def = FunctionsDefinitions.getInstance();
   Method method = ExprFunctionTest.class.getMethod("myTest", Integer.TYPE, Integer.TYPE);
   def.addFunction("test", this, method);
 

For the function with the following signature:

  public int myTest(int a, int b) {
     return a + b;
  }
 

The function can then be called as for example:

 test(1, 2)
 

Parameters:

name - the name of the function (to be used in the expressions)

obj - the object holding the associated Java method

method - the Java method