Re: [Factor-talk] Different conventions for tuples

[Eduardo C. <way...@gm...>]

On Monday 16 July 2007 18:51, Slava Pestov wrote:

> Most tuple constructors do the following things only:
>
> - Set the delegate
> - Set slot values from the stack
> - Set slot values to some default value
>
> Perhaps this can be incorporated into the TUPLE: form, then we won't
> need most C:'s at all?

One constructor doesn't fit all, in some cases. In Smalltalk, if you browse class methods (as opposed to instance methods), they're often constructors. And there are often many constructors because there may be many ways to setup an object.

A BOA-constructor should always be available. Custom constructors should be defined explictly.

So I like the idea of syntax to specify constructors. But maybe it should not be embedded in the TUPLE: form; There's only one TUPLE: form per class, but there may be many constructors.

However, I think it's an interesting idea and I'd like to see it developed and explored.

There's consensus that C:'s often have boilerplate. There's two ways to solve this. One way is to use a more complicated declarative version of TUPLE: that bakes in what we've been doing, but hides it. Another way is to find better stack effects for 'set-delegate' and the slot setters which will impact all constructors in a positive way. An expression in terms of well designed words should ideally be very close to a declarative expression. Syntax should be minimal. As in Lisp, if something can be done equally well with a function or macro, go with the function.

Anyways, this is too high a talk-to-code ratio for my taste :-) Let's try some of this stuff out. For my part, I've already coded up the alternative tuple ideas:

	http://dharmatech.onigirihouse.com/tuples-alt.factor
	http://dharmatech.onigirihouse.com/slots-alt.factor

I'm ready to recode all my stuff in terms of it, but then I'd be living in a parallel world as I did with the module system. :-/ It feels nice to finally be on the same page as everyone else. But if I must play in the corner all by myself, so be it. :-)

I wouldn't mind putting these in extra/ but slot's are a pretty low level thing that get's hacked every once in a while (Slava's work on runtime changes to tuple shapes) and my stuff would have to be adjusted.

Ed