On 9/24/2011 6:39 PM, Peter Alexander wrote:
On 25/09/11 12:08 AM, Walter Bright wrote:
3. support for true functional programming
Purity and (physical) immutability are separate concepts. Having immutable
arguments is neither a necessary or sufficient condition for being pure.
What do you mean by "true functional programming"? Just pure functional
programming?
As I explained in my 'Thoughts on Immutability in D' post, physical immutability
is far too restrictive for functional programming, so I would say that immutable
in D restricts true functional programming rather than supporting it. Supporting
functional programming would mean supporting logical immutability, because
that's all functional programs care about.
Functional programming means (in part) no side effects of functions, which means
that global state cannot be modified through the parameters. Having the
parameters be const/immutable is how this can be statically guaranteed.
