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import org.nfunk.jep.*;
/**
* An example class to test custom functions with JEP.
*/
class CustFunc {
/**
* Constructor.
*/
public CustFunc() {
}
/**
* Main method. Create a new JEP object and parse an example expression
* that uses the SquareRoot function.
*/
public static void main(String args[]) {
JEP parser = new JEP(); // Create a new parser
String expr = "1 + half(2)";
double value;
System.out.println("Starting CustFunc...");
parser.addStandardFunctions();
parser.addStandardConstants();
parser.addFunction("half", new Half()); // Add the custom function
parser.parseExpression(expr); // Parse the expression
if (parser.hasError()) {
System.out.println("Error while parsing");
System.out.println(parser.getErrorInfo());
return;
}
value = parser.getValue(); // Get the value
if (parser.hasError()) {
System.out.println("Error during evaluation");
System.out.println(parser.getErrorInfo());
return;
}
System.out.println(expr + " = " + value); // Print value
}
}
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