Re: [stack] Re: Barebone implementation of concatenative language in c or c++

John Nowak <[email protected]> wrote:
> Don Groves wrote:
>> Isn't call-by-reference essentially equivalent to lazy evaluation?
> Nope. Call-by-reference is an abomination that shouldn't exist. Lazy evaluation is unrelated.

Heh. John, is this because CBR hypothetically allows mutation of
arbitrary items? I'm not sure that it shouldn't exist, but it should
certainly be confined to explicitly declared OUT parameters.

> A quick run through here should help:
> http://en.wikipedia.org/wiki/Evaluation_strategy

Yes, that's what I used after I wrote my first draft to make it look
like I knew what I was talking about.

> Caveat: It is possible to have an eager yet non-strict language. Wikipedia conflates eagerness and strictness which is unfortunate, although most existing eager languages are indeed strict. The Id programming language is an example of an eager, non-strict language.

WP's explanation of non-strictness on that page is pathetic. BUT, I'm
puzzled... Their definition is clear, and it matches what the first
pageful Google results seem to be using, and their definition utterly
precludes yours... So I'm curious. How is Id both eager and
non-strict?

> Wikipedia is bad at precision.

If this is true, its accuracy is more to be bemoaned than its precision.

Usually its clarity is worse. Especially in highly technical matters.

> Concatenative languages do not have lambda abstractions, but you can achieve a similar result by placing a function on the stack and lifting values into it (e.g. via Factor's misnamed 'curry' function; it really should be called 'partial-apply' or similar, although that's not exactly right either).

In a more general sense, what you're describing is passing a function
_as_ data -- not data inside a function, but rather a function as
data.

> - jn

-Wm