Calling java function with optional parameters from Clojure [duplicate]

Question

I want to use mXparser from clojure which has an Expression Java class with multiple constructors:

public Expression(PrimitiveElement...elements) { ... }

public Expression(String expressionString, PrimitiveElement...elements) { ... }

In Java I can create new instance with a String argument:

Expression e = new Expression("1+2");

I assume it is using the second constructor because the first argument is string and the second is optional.

Now I want to do the same in clojure:

(Expression. "1+2")

It fails with

java.lang.String cannot be cast to [Lorg.mariuszgromada.math.mxparser.PrimitiveElement;

Looks like it is trying to use the first constructor which is not what I want.

How can I create a new instance of this class in Clojure only with a string argument?

You have to specify the varargs argument, stackoverflow.com/q/11702184. — glts
– glts, Commented Jan 7, 2018 at 15:11

Zoe - Save the data dump · Accepted Answer · 2019-04-28 11:35:52Z

1

According to the comment from glts it works in this way:

(Expression. "1+2" (into-array PrimitiveElement []))

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answered Jan 7, 2018 at 15:30

koszti

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