pre-PEP: Simple Thunks

[Kay Schluehr]

Ron_Adam wrote:

> I sort of wonder if this is one of those things that looks like it
> could be useful at first, but it turns out that using functions and
> class's in the proper way, is also the best way. (?)

I think Your block is more low level. It is like copying and pasting
code-fragments together but in reversed direction: if You copy and
paste a code fragment and wants to change the behaviour You probable
have to change the fragment the same way in every place of occurence.
This is a well known anti-pattern in software construction. If You
change Your thunk somehow e.g. from

def yield_thunk:
    yield i

to

def yield_thunk:
    yield j

You have to change all the environments that use the thunk e.g.
renaming variables. It is the opposite direction of creating
abstractions i.e. a method to deabstract functions: introduce less
modularity and more direct dependencies. This is the reason why those
macros are harmfull and should be abandoned from high level languages (
using them in C is reasonable because code expansion can be time
efficient and it is also a way to deal with parametric polymorphism but
Python won't benefit from either of this issues ).

Ciao,
Kay