On 05/15/2014 07:41 PM, Steven Schveighoffer wrote:
Not really, allocation is just an implementation detail. The
computational language is meaningful independent of how you might
achieve evaluation of expressions. I can in principle evaluate an
expression of such a language on paper without managing a separate
store, even though this usually will help efficiency.
Functional programming languages are not about taking away features
from a procedural core language. They are based on the idea that the
fundamental operation is substitution of terms.
But they do not deal in explicit pointers.
(Well,
http://hackage.haskell.org/package/base-4.7.0.0/docs/Foreign-Marshal-Alloc.html#v:malloc
)
Otherwise, that's a can of
worms that would weaken the guarantees, similar to how D's guarantees
are weakened.
...
The concept of a 'pointer' to some primitive value does not have a
meaning in such languages. Every value is an "rvalue".
We have no choice in D, we must accept that explicit pointers are used.
...
We could e.g. ban comparing immutable references for identity /
in-memory order.
To be honest, code that would exploit such an anomaly is only ever used
in "proof" exercises, and never in real code.
Hashtables are quite real.
Pretend I'm ignorant, what does this imply?
...
E.g. order of iteration may be dependent on in-memory order of keys and
the 'same' keys might occur multiple times.
This is the issue:
On Thu, 15 May 2014 10:48:07 +0000
Don via Digitalmars-d <digitalmars-d@puremagic.com> wrote:
Yes. 'strong pure' means pure in the way that the functional
language crowd means 'pure'.
'weak pure' just means doesn't use globals.
There is no way to make that claim precise in an adequate way such
that it is correct.
This doesn't help, I'm lost with this statement.
-Steve
The issue is that there are apparently different expectations about what
the keyword is supposed to do.
