Re: [stack] impure concatenativity: let without translation

John Nowak <[email protected]> wrote:
> William Tanksley, Jr wrote:
>  > We're dealing with largely imperative languages here; they're always
>  > going to be clearer when expressing algorithms than they are when
>  > expressing formulas.

>  Perhaps this shows a difference in our thinking here. I'm interested
>  in making concatenative languages feel as declarative as possible. It
>  seems to me that variables are necessary to achieve that in some cases.

That's a great goal. One odd thing about concatenative languages is
that even the least functionally pure of them (like Forth) tends to
feel declarative while I'm coding in it -- my mental patterns are
similar to the ones I fall into while coding in declarative functional
languages. But, at the same time, Forth is undeniably imperative.

There's definitely more that can be done to make concatenative
languages that feel declarative. I suspect, however, that making
concatenative languages that simply look familiar to applicative
language programmers is risky since it can cause false positives.

But I'm not sure that local variables are bad here. I'm of two minds on this.

>  > Either way, your work is very interesting. I don't know what an
>  > "effect system" is, by the way.

>  An effect system is what Haskell programmers wish they had, even if
>  they don't know it. Such a system as it works in Fifth allows you to
>  freely mix effectful and pure code however you wish. The effect system
>  is powerful enough to sort out what you're doing and, with complete
>  accuracy, tell you which functions are pure and which aren't. In the

Oh, very nice!

>  - John

-Wm