Herb Sutter briefly discusses D during interview

[Ali Çehreli]

On 06/07/2011 11:59 PM, Jonathan M Davis wrote:
 > On 2011-06-07 23:43, Vladimir Panteleev wrote:

 >> // Old, C/C++-like syntax - I understand this is pending deprecation
 >> int a[3][4];
 >> static assert(a.length == 3);
 >> static assert(a[0].length == 4);
 >>
 >> // New D syntax
 >> int[4][3] b;
 >> static assert(b.length == 3);
 >> static assert(b[0].length == 4);
 >
 > Declarations are read outward from the variable name. That's 
generally right-
 > to-left.

The important word there is "generally". How can we say that there is 
any rule when right-to-left is only "generally"?

 > Putting the array dimensions on the right side results in it being
 > left-to-right, but that's not the norm.
 >
 > int* a; //A pointer to an int

No. The type is int* (I read it as "int pointer"), and the variable name 
is a. I don't have to read it at one breath.

 > int** b; //A pointer to a pointer to an int.

No. The type is int** (I read it consistently as "int pointer pointer"), 
and the variable name is b.

 > Left-to-right would end up being something more like this:
 >
 > a *int;
 >
 > or maybe
 >
 > *int a;
 >
 > The D syntax for static array sizes just underlines the fact that 
declarations
 > are generally read right-to-left because in that particular case, 
it's not
 > what people expect.

I don't read them that way. Perhaps we should say that the English 
speakers may read right-to-left? Perhaps only when they need to 
understand a very complicated declaration?

 > Herb Sutter is positing that the syntax would be easier to
 > grok and result in fewer errors if it were all left-to-right instead 
of right-
 > to-left.

D has left-to-right: Type on the left, variable on the right. Consistent.

 > Yes, there are a few cases where you end up with left-to-right in C-
 > based languages, because declarations are typically read outward from the
 > variable name, and if that includes stuff to the right of the 
variable name,
 > then that part is read left-to-right, but that's the exception.

I can't remember such exceptions in D? (Well, 'alias this' comes to 
mind.) Multi-dimensional array declarations and function pointer 
declarations are corrected in D. That is consistent.

 >
 > - Jonathan M Davis

Ali