Noob: What is a slot? Me trying to understand another's code

[Gabriel Genellina]

En Tue, 04 Sep 2007 15:03:16 -0300, Carnell, James E  
<jecarnell at saintfrancis.com> escribi�:

> MY QUESTION:
> What is a slot? In class Object below the __init__ has a slot.  Note:
> The slot makes use of a data object called 'percept' that is used in the
> TableDrivenAgent(Agent) at the bottom of this post. I am guessing this
> is a type of Finite State Machine (I haven't bought the book yet so I am
> guessing).

The authors appear to be using the term in a very general sense - meaning  
"something that has to be filled in".
That is, you (the programmer) is supposed to "fill" the slot with  
meaningful code or data.

> [...] You subclass Object to get the objects you want.  Each object can
> have a .__name__  slot (used for output only).
> [...] An Agent is a subclass of Object with one required slot,
>     .program, which should hold a function that takes one argument, the
>     percept, and returns an action. Note that 'program' is a slot, not a  
> method.

Here they're trying to bind a simple function (not a method) to a name. I  
don't see the point in forcing things that way, maybe the authors have  
good reasons. But I'd use a staticmethod instead, perhaps.

Note: The C Python source code does use "slots", fields in a structure  
holding function pointers. For example, filling the nb_add slot in a type  
object, one can evaluate a+b for instances of that type.

-- 
Gabriel Genellina