Poly/ML 抛出异常 "toAddress"

Question

使用Poly/ML，我想编写一个函数来使用数组的数组构造一个 n*n 单位矩阵。

我写了：

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

编译成功，给出

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

但是当我调用 idmatrix

idmatrix 2;

对于测试，编译器的输出是

> Exception- Cast "toAddress" raised

任何人都可以解释为什么会引发异常吗？

非常感谢！

Answer 1

你的代码对我来说工作正常。看the code that raises the exception，可能是32/64位地址的问题？您的 Poly/ML 是否针对正确的架构编译？

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

莫斯科 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

和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

Poly/ML 抛出异常 "toAddress"

Poly/ML Exception Cast "toAddress" raised

sml

polyml