BoundFunc has no name

[Mattia72]

[Moderator's note: Topic moved from Bug Reports.]

If I create a FuncObj with Bind Method, it doesn't get a name.

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DoNothing(msg) {
}

fn := DoNothing.Bind('something')
if (fn.Name = '')
  throw Error('DoNothing has no name')

; But so works:
fo := DoNothing
fn := fo.Bind('something')
if (fn.Name = '')
  throw Error('DoNothing has no name')

[iseahound]

When you bind an argument to a function, it should have a different name.

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; Assume there is a function called Max(x, y) which returnss the greater of x and y.

; We now can create a greater than or equal to function.
greaterThan100 := Max.Bind(100)

; Same as: (y >= 100) ? y : 100
MsgBox greaterThan100(200) ; True (200)
MsgBox greaterThan100(50) ; False (100)

[lexikos]

fn is not DoNothing. Does the documentation give you reason to believe that it should have the same name?

Other properties and methods are inherited from Func, but do not reflect the properties of the target function or method (which is not required to be implemented as a function). The BoundFunc acts as an anonymous variadic function with no other formal parameters, similar to the fat arrow function below:

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Func_Bind(fn, bound_args*) {
    return (args*) => (args.InsertAt(1, bound_args*), fn(args*))
}

Source: Function Objects - Definition & Usage | AutoHotkey v2

[Mattia72]

Ok, but I think that is a little bit strange that there is difference between the two constructs:

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DoNothing(msg) {
}
fn := DoNothing.Bind('something') ; no name

and

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fo := DoNothing
fn := fo.Bind('something') ; name=DoNothing

If I want to call a Bound Function by name, I have to choose the second one and not to forget, not to refactor it later.

[niCode]

Unless the latest version of 2.1 has changed something, then neither of the examples you gave are correct for me. fn.Name is blank every time.

[Mattia72]

You're right, I overlooked something

[Mattia72]

In this example, I commented the real state.

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DoNothing(msg) {
  MsgBox(msg)
}

fn1 := DoNothing.Bind('something') ; no name
fo := DoNothing                             ; fo.Name = DoNothing
fn2 := fo.Bind('something')             ; no name

fn2.Call()                                     ; ok
%fo.Name%.Call("something")        ; ok

%fn1.Name%.Call()                       ; doesn't work
%fn2.Name%.Call()                       ; doesn't work

[niCode]

How would you call this separate line of code here:

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() => MsgBox('I am an anonymous fat-arrow function')

Without a reference, you can't. It's anonymous, it has no name.

When you use .Bind(), you're essentially creating a new function, one that has no name. It may reference DoNothing, but it is not DoNothing.



I'd be curious to know the purpose of this:

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%fn1.Name%.Call()

If fn1 is already a reference to a BoundFunc, then call fn1. You don't need to know the name.