com.singularsys.jep.misc
Class LightWeightComponentSet

java.lang.Object
  extended by com.singularsys.jep.ComponentSet
      extended by com.singularsys.jep.misc.LightWeightComponentSet

public class LightWeightComponentSet
extends ComponentSet

A lightweight set of components reusing components from an existing Jep instance. This class will reuse the NumberFactory, VariableFactory, FunctionTable, OperatorTable, and PrintVisitor components of the supplied Jep. It will have a NullParser so it can not be used for parsing expressions. New copies of the VariableTable, StandardEvaluator and NodeFactory are used. The VariableTable will be filled with the copies of the variables in the supplied instances' variable table.

To construct a lightweight jep instance use

 Jep j = new Jep();
 LightWeightComponentSet lwcs = new LightWeightComponentSet(j);
 Jep j2 = new Jep(lwcs);
 

Such instance typically use 1kB compared to 56kB bytes for a Jep instance with a StandardParser and 14kB bytes with a configurable parser.

As this reuses the function table and PostfixMathCommands in it. There may be cases where the pfmc are not optimized for use in multiple threads Random is the only example of this. While safe to use in multiple threads efficiency is improved if each thread has its own copy. If this is an issue the shallowCopy() methods of function table can be used.

 Jep j = new Jep();
 LightWeightComponentSet lwcs = new LightWeightComponentSet(j);
 FunctionTable ft = lwcs.getFunctionTable().shallowCopy();
 // use new instances of the pfmc's
 lwcs.setFunctionTable(ft);
 


Field Summary
 
Fields inherited from class com.singularsys.jep.ComponentSet
auxComps, evaluator, funTab, nodeFac, numFac, opTab, parser, pv, varFac, varTab
 
Constructor Summary
LightWeightComponentSet(Jep jep)
          Create a lightweight instance with copies of all variables
LightWeightComponentSet(Jep jep, boolean copyConstants)
          Create a lightweight instance either with an empty variable table or one with just the constants.
 
Method Summary
 
Methods inherited from class com.singularsys.jep.ComponentSet
addAuxComponent, getAuxComponents, getAuxComps, getBaseComponents, getComponents, getEvaluator, getFunctionTable, getNodeFactory, getNumberFactory, getOperatorTable, getParser, getPrintVisitor, getVariableFactory, getVariableTable, setAuxComps, setEvaluator, setFunctionTable, setNodeFactory, setNumberFactory, setOperatorTable, setParser, setPrintVisitor, setVariableFactory, setVariableTable
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

LightWeightComponentSet

public LightWeightComponentSet(Jep jep)
Create a lightweight instance with copies of all variables


LightWeightComponentSet

public LightWeightComponentSet(Jep jep,
                               boolean copyConstants)
Create a lightweight instance either with an empty variable table or one with just the constants.

Parameters:
jep - the source instance
copyConstants - if true copy the constants, if false leave empty


Copyright © 2010 Singular Systems http://www.singularsys.com/jep