Re: Passing Message Input Index to

[Marcus Müller]

Hi Merlo,

On 29.06.22 18:53, Merlo, Jason wrote:
> A separate function can be 
> registered for each input, however I would need to dynamically generate functions based on 
> the number of inputs a user has configured, which has been giving me trouble. Ideally, the 
> function handler callback would provide auxiliary arguments to pass to the callback 
> function as arguments that can be bound at instantiation (such as index), but I don't 
> think this is possible.

It definitely is! It's what lambdas are for.
I've written a small illustration for you: https://gcc.godbolt.org/z/cssn8hMno

Here, "float divide(int, int)" is your function that takes an extra argument (in case of 
your universal message handler, that might be the name of the handler).

with [capture](arguments) { return something; } you can write an anonymous function (a 
lambda) that "knows" its "captured" values, and still takes arguments.

> Presently, I've looked into the functools package |partialmethod| to create separate 
> instances of the |process_msg(self, msg, idx)| method with the |ch_idx| argument set, 
> effectively creating |process_msg_idx(self, msg)| dynamically based on the number of 
> inputs the user desires like:
Oh, this is python. Makes it a bit easier;

handler_name = something
lambda argument: underlying_function(argument, handler_name)

curries underlying function to have its second argument already set, i.e. down to a 
function of a single variable.

Best regards,
Marcus