Re: [rust-dev] parameterizing types and functions by integers

2013-08-23 Thread Brendan Zabarauskas 
This would be amazing. At the moment the [T,..n] types are pretty damn useless 
when it comes to generics.
Mathematics, science and units of measure libs would find constant 
parametrisation most useful.

I could imagine something like:

  fn dotT: Ring, N: uint(a: [T, ..N], b: [T, ..N]) - T { … }

or

  // Forgive me if I get these dimensions around the wrong way!
  fn mul_matT: Ring, M: uint, N: uint, O: uint(a: [[T, ..N], ..M], b: [[T, 
..O], ..M]) - [[T, ..N],..O] { … }

  fn transposeT: Ring, M: uint, N: uint(a: [[T, ..N], ..M]) - [[T, ..M], 
..N] { … }

~Brendan

On 23/08/2013, at 3:22 PM, Geoffrey Irving irv...@naml.us wrote:

 Does rust have compile time sized arrays, equivalent to the following C++ 
 definition?
 
templateint d,class T struct array {
   T x[d];
};
 
 More generally, is it possible to parameterize types by integers, so that 
 types like the above can be built up?
 
 Finally, is it possible to parameterize functions over integers, as in
 
fn concatT,a,b(x : arraya,T, y : arrayb,T) - arraya+b,T { ... }
 
 If integer type arguments aren't built in, is it possible to type the concat 
 function using a type-based encoding of naturals?
 
 Thanks!
 Geoffrey
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[rust-dev] parameterizing types and functions by integers

2013-08-22 Thread Geoffrey Irving 
Does rust have compile time sized arrays, equivalent to the following C++
definition?

templateint d,class T struct array {
   T x[d];
};

More generally, is it possible to parameterize types by integers, so that
types like the above can be built up?

Finally, is it possible to parameterize functions over integers, as in

fn concatT,a,b(x : arraya,T, y : arrayb,T) - arraya+b,T { ... }

If integer type arguments aren't built in, is it possible to type the
concat function using a type-based encoding of naturals?

Thanks!
Geoffrey
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Re: [rust-dev] parameterizing types and functions by integers

2013-08-22 Thread Geoffrey Irving 
Thanks for the quick reply (also adding back the list).

Geoffrey


On Thu, Aug 22, 2013 at 10:28 PM, John jmgro...@gmail.com wrote:

 For the moment, no, that's not possible.
 On Aug 22, 2013 10:23 PM, Geoffrey Irving irv...@naml.us wrote:

  Does rust have compile time sized arrays, equivalent to the following
 C++ definition?

 templateint d,class T struct array {
T x[d];
 };

 More generally, is it possible to parameterize types by integers, so that
 types like the above can be built up?

 Finally, is it possible to parameterize functions over integers, as in

 fn concatT,a,b(x : arraya,T, y : arrayb,T) - arraya+b,T {
 ... }

 If integer type arguments aren't built in, is it possible to type the
 concat function using a type-based encoding of naturals?

 Thanks!
 Geoffrey

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 Rust-dev mailing list
 Rust-dev@mozilla.org
 https://mail.mozilla.org/listinfo/rust-dev


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