🚀 go-pugleaf

In article <3407.2720318d@cc.helsinki.fi> jpiitulainen@cc.helsinki.fi writes:
> In article <+CI6:YD@xds13.ferranti.com>, peter@ficc.ferranti.com (Peter
> da Silva) writes:
> > In article <415@data.UUCP> kend@data.UUCP (Ken Dickey) writes:
> >> There are a number of programming languages, Scheme and ML among them,
> >> which do not have a pointer abstraction.

> > The *only* abstractions in scheme are a pair of pointers or a value.

> It is a pair of values.  Pointers to values, as separate from values, do
> not exist.

So, (a) is the same as a?

> Pointers (addresses) are usually used in the implementation,

No, addresses are not what I mean by pointers. The definition of a pointer
that I am using is "a token that can refer to any language object". The
operative word is "any".

> In Scheme, any
> pair or vector can hold arbitrarily big values---even itself---pointers
> are not needed and there is no such thing as a pointer to an integer.

Really? As far as aliasing and debugging are concerned (3) is a pointer
to 3. (well, to 3 and nil)

> The same problems are there, when applicable.  Lists are just chains of
> pairs, or pairs who's cdr fields are pairs, and the cdr pair can be a
> part of some other list, too.  Thus mutation is dangerous.

*Exactly*, just as arbitrary pointer operations are dangerous. And for
exactly the same reasons.
-- 
Peter da Silva.   `-_-'
+1 713 274 5180.   'U`
peter@ferranti.com