Re: and-let* is not composable?

[Panicz Maciej Godek]

2013/9/10 Ian Price <address@hidden>

I have a few notes unrelated to those I've already mentioned in the
thread.

1. Guile already has curried definitions in (ice-9 curried-definitions)

Yes, but those are completely different. I wouldn't call "define-curried"

a curried definition, but a definition of a curried macro for generating

procedures.

 

2. By turning your functions definitions into a macro, you've lost the
ability to use them in a first class manner.

That's not entirely true. I just need an extra pair of parentheses

to do so. The semantics is certainly different than the one of

Guile's curried definitions, but that's fine.

 

3. I would strongly recommend _not_ using define-macro, and even more
so, not mixing define-macro and syntax-rules in a macro. Syntax-case is
as powerful as defmacro, and in most practical cases, about as much
writing.

Well, while syntax-rules macros are quite easy to understand

(at least from the user's point of view), although sometimes a little

tricky, the syntax-case system I find still too difficult to use.

define-macro, on the other hand, is very easy to explain

even to beginner programmers, although the resulting macros

are much more difficult to analyse.

The main problem with syntax-rules/syntax-case macros is

the treatment of ellipses, which makes it difficult to create

macros that create macros.

Still, I didn't post to comp.lang.scheme for no reason :)

4. What your macro does is not currying, it is partial
application. Those are different things. Currying refers to the process
of turning a function of n arguments into an n-nested set of 1 argument
functions. Partial application is, well, not supplying all the arguments
to a function. You can have partial application without currying, as
your macro shows.

OK, you got me here. But it's still difficult for me to come up

with a good name for that macro (and if so, the Guile's curried

definitions are not curried either, at least in general: because

you can (define ((f a b) c d) ...), getting a chain of 2-argument

functions)

Thanks,

M.