Can we pass min and max number of arguments in Function constructor ??

[Rabi-Narayan]

We are getting Expressions dynamically and we have no idea how many of arguments there will be.So how can we achieve this.Can somebody guide us.Thanks in advance.

Ex :- Expression e = new ExpressionBuilder("sum(1,avg(1,2,3))")
.functions(variableArgsFunctions)
.build();

"sum(1,avg(1,2,3))" expression we will get dynamically.In some cases it may be sum(1,avg(1,2,3,4)).

How can we achieve this.

[subramaniant]

Hi Rabi Narayan,

Go to -> net.objecthunter.exp4j.Expression.evaluate() --> replace or modify as below (removing check for number of arugment...Perfect way is to add one function without num argument ) ..
....
} else if (t.getType() == Token.TOKEN_FUNCTION) {
FunctionToken func = (FunctionToken) t;
final int numArguments = func.getFunction().getNumArguments();
// if (output.size() < numArguments) {
// throw new IllegalArgumentException("Invalid number of arguments available for '" + func.getFunction().getName() + "' function");
// }
/* collect the arguments from the stack */
double[] args = new double[output.size()];
for (int j = numArguments - 1; j >= 0; j--) {
args[j] = output.pop();
}
output.push(func.getFunction().apply(args));
}
...

Please let me know , if you have any issue on this..

Thanks