How to overload an operator ?

[srilakshmikanthanp]

Can I overload an operator like + to evaluate custom types like,

const add = (one, two) => {
 if (typeof one === 'object' && typeof two === 'number') {
    for (let key in obj) {
      obj[key] += two;
    }
 }

 // handle other cases ...
}

const getObject = () => {
  return { one: 2, two: 2 }
}

evaluate(`getObject() + 2') // { one: 4, two: 4 }

How do I put the overloaded add to the evaluator?

[srilakshmikanthanp]

Or Can I implement a custom datatype to do the tasks, how to do it?

[dvd101x]

You could import to your function a typed function with a new type signature.

math.import(
    {
        add: math.typed(
            {
                'Object, number': (obj, num) => {
                    for (key in obj){
                        obj[key] += num
                    }
                    return obj
                }
            }
        )
    }
)

Reference

https://mathjs.org/docs/core/extension.html

[dvd101x]

It is also possible to add new custom types and add convertions between types.

But if the type already exists (like object) then the best way is to import the missing type signatures to the function you need.

Reference

https://mathjs.org/docs/core/extension.html#typed-functions
https://github.com/josdejong/typed-function