Dynamic function call

Victor Vodovozov

I have an Assoc with associated function names to an object type:

functionList = Assoc{

'type1': Assoc{

'method1': 'method1ForType1'

'method2': 'method2ForType1'

}

}

How can I call some function with a name generated from a variable based on the functionList?

I need something like:

funcName = functionList[objType]['method1']

.(funcName)() <-- here is the function call which I need

Chris Meyer

The syntax is as you have it:

.(funcName)() 

The funcName parameter can be a String or a Script. You'll get a stack trace if the function doesn't exist, or if you pass in the incorrect number of parameters.

For error handling, you may want to check if a function exists before calling it. You can use the following function for this:

function Boolean IsScript(Object obj, String funcName)
	return IsFeature(obj, funcName) \
		and (Type(obj.(funcName)) == ScriptType)
end

Usage:

if IsScript(this, funcName)
	this.(funcName)()
else
	// handle error
end

It's also possible to assert the function interface, but that's a little more complicated.