Poly/ML Exception Cast "toAddress" raised

Using Poly/ML, I wanted to write a function to construct an n*n identity matrix using Array of Arrays.

I wrote:

fun equiv x y = if x = y then 1 else 0;
fun idmatrix n = Array.tabulate(n, fn i => (Array.tabulate(n, equiv i)));

and it compiled successfully, giving

> val equiv = fn: ''a -> ''a -> int
> val idmatrix = fn: int -> int array array

But when I called idmatrix

idmatrix 2;

for a test, the output of the compiler was

> Exception- Cast "toAddress" raised

Can anybody explain why the exception was raised, please?

Thank you very much!

Solution

Your code works fine for me. Looking at the code that raises the exception, perhaps it's a 32/64-bit address problem? Is your Poly/ML compiled for the right architecture?

Poly/ML:

$ poly
Poly/ML 5.2 Release
> fun equiv x y = if x = y then 1 else 0;
val equiv = fn : ''a -> ''a -> int
> fun idmatrix n = Array.tabulate(n, fn i => (Array.tabulate(n, equiv i)));
val idmatrix = fn : int -> int Array.array Array.array
> idmatrix 3;
val it = fromList[fromList[1, 0, 0], fromList[0, 1, 0], fromList[0, 0, 1]]
: int Array.array Array.array

Moscow ML:

$ mosml
Moscow ML version 2.10
Enter `quit();' to quit.
- fun equiv x y = if x = y then 1 else 0;
> val ''a equiv = fn : ''a -> ''a -> int
- fun idmatrix n = Array.tabulate(n, fn i => (Array.tabulate(n, equiv i)));
> val idmatrix = fn : int -> int array array
- idmatrix 3;
> val it = <array> : int array array

And SML/NJ:

$ sml
Standard ML of New Jersey v110.76 [built: Sun Jun 29 03:29:51 2014]
- fun equiv x y = if x = y then 1 else 0;
stdIn:1.23 Warning: calling polyEqual
val equiv = fn : ''a -> ''a -> int
- fun idmatrix n = Array.tabulate(n, fn i => (Array.tabulate(n, equiv i)));
[autoloading]
[library $SMLNJ-BASIS/basis.cm is stable]
[autoloading done]
val idmatrix = fn : int -> int array array
- idmatrix 3;
val it = [|[|1,0,0|],[|0,1,0|],[|0,0,1|]|] : int array array