how to get a function's info in actionscript? - actionscript-3

Question

i often get argument mismatch error ,that usually take me a lot of time to debug program.damn, i really hope i know the function's entrance requirement and where they are come from.
since i only know a function variable is a function,no any other information.
i wrote massive codes like this
public static function call(func:Function,params:Array = null,addToTailIfNotNull:*=null):void{
if (func!=null){
var args:Array =[];
if(params!=null){
args = ArrayTools.clone(params);
}
if (addToTailIfNotNull!=null){
args.push(addToTailIfNotNull);
}
func.apply(null,args);
}
}
i should do things more smartly .

Answer 1

I can suggest you using flash.utils.describeType() method. It returns an XML with a description of an object you passed as a parameter.
Lets say you have a Class:
public class Example {
public function someMethod(number:Number, string:String):void {
}
}
And you call somewhere:
flash.utils.describeType(Example);
You should get an XML with something like this in there:
<method name="someMethod" declaredBy="com.example::Example" returnType="void">
<parameter index="1" type="Number" optional="false"/>
<parameter index="2" type="String" optional="false"/>
<metadata name="__go_to_definition_help">
<arg key="pos" value="501"/>
</metadata>
</method>
I am not sure that this is what you looking for, as in your example if you pass you Function argument there you will get a description of Function class:
<type name="builtin.as$0::MethodClosure" base="Function" isDynamic="false" isFinal="true" isStatic="false">
<extendsClass type="Function"/>
<extendsClass type="Object"/>
<accessor name="length" access="readonly" type="int" declaredBy="Function"/>
<accessor name="prototype" access="readwrite" type="*" declaredBy="builtin.as$0::MethodClosure"/>
</type>
But maybe you can refactor you "call" method so it could get the right description (for example pass additional info into it - like an object class and a method name - so you could analyse the method signature in it. Not the most beautiful solution, but still...)