Function to flip boolean attributes

I'm trying to create a function that receives a parameter (an object.attribute) and flips that boolean attribute. I'm not sure how to get the syntax right.

Here's what I've got. I created a function that takes one parameter (which I've named: attrib).

And here's the script I've got right now:

if (attrib = true) {
  attrib = false
}
else {
  attrib = true
}

I am guessing I've 1) got a syntax error in this, 2) it's not substituting the parameter's reference for the parameter name, or 3) both. What have I done wrong?

Edit: I should add. The function seems to run. I attached it to a test verb and fed it an object.attribute for parameter. But the boolean doesn't flip.


attrib is a local variable. It doesn't exist outside your function. Parameters in Quest are not passed by reference unless they are lists or dictionaries.

I also don't see why you would need such a function for something that you can already write in one line.

someobject.someattribute = not someobject.someattribute

If you want to set an attribute from within a function, you need two parameters: the object, and the attribute name.
Theoretically you could do something like:

<function name="FlipBoolean" parameters="obj, attr">
  set (obj, attr, not GetBoolean (obj, attr))
</function>

But to use that function, you'd be writing:

FlipBoolean (object, "myflag")

which is barely shorter than

object.myflag = not object.myflag

I keep confusing myself. Let me step back and explain the context. Perhaps you can explain the logical way to do it.

I have a box with multiple lights. The box has an attribute for each light. light_1, light_2, etc.

So I want to have a command or a verb or something where they say "toggle 1" and it toggles the attribute Box.light_1

And so I thought I'd create a function where the function handles the toggle part of it, and I pass that function the object. And based on the parameter "1" or "2" I'd change that corresponding attribute on the Box object.

Does that make sense?


That makes sense.

I think the 'FlipBoolean' function I posted above looks like what you want, then. It takes two parameters; an object and an attribute name.
It uses the function GetBoolean to get the value of a boolean attribute, given the object and attribute name; the not operator turns true into false or vice versa; and set sets an attribute when given an object, attribute name, and a new value.

The first parameter is the box; the second parameter is the name of the attribute.

Or if all the lights are on the same box, you could make a function with a single parameter number.
Its script would look like:

attrib = "light_" + number
state = GetBoolean (box, attrib)
set (box, attrib, not state)

(You could shrink this down to one line, set (box, "light_"+number, not GetBoolean (box, "light_"+number)), but that's a little harder to read)


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