const?? When and why? This is ugly!

[Jarrett Billingsley]

On Mon, Mar 2, 2009 at 1:32 PM, hasen <hasan.aljudy at gmail.com> wrote:

> How about, adding a new attribute to functions: `pure`
>
> pure real sin( real x ) { ... }
>
> and design the rest around this concept.
>
> The compiler must make sure that this function is really pure:
> - native types must be passed by value, not by reference
> - doesn't accept pointers
> - <insert some condition for objects and arrays>
>
> If these requirements aren't met, the compiler will spit some error message
> "in function <F>: doing <X> voilates the `pure` attribute"

Umm.. maybe you didn't read far enough, but D2 already has pure functions.
http://www.digitalmars.com/d/2.0/function.html

> Also, make `string` a builtin type that's immutable (like python), and
> discourage the use of char[] as a type for strings, (unless used to
> implement a special string class).
>
> The need for a special string type also stems from the fact that char[a..b]
> slices bytes, not characters!

Again, 'string' is defined as an alias to invariant(char)[].  It's an
immutable builtin type.  It still has the problem of slicing/indexing
on bytes rather than characters, but the alias is already there,
Phobos already uses it extensively, and if it were changed to a struct
in the future it would probably cause few to no problems.