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Eqaulity on 2D Arrays - A bug?
f#

Hi All,

I am playing with 2D arrays at the moment and an interesting thing happened. When I run the following:

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let  test16 = 

   

  let temp = Array2.create 1 1 1  

   

  let temp2 = Array2.create 1 1 1

   

  temp = temp2

I get the following error:

"Argument Exception: Array was not a one-dimensional array."

However

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let  test17 = 

     let temp = Array2.create 1 1 2  

     let temp2 = Array2.create 1 1 1

     temp = temp2

works fine.

I have tried a range of combinations of argument types and dimernsions. Whenever the array dimensions are not equal the function works, otherwise I get the error.

If '=' operation cannot be applied applied to a 2D array I should get a type checker error?

Otherwise is this an interal bug?

Or most likely of all am I doing something wrong?
BTW I am running 1.9.2.9

.

Hi Mattie,

Yes, this is a bug.

The "=" operator can be used with all F# types, which should always implement structural equality (e.g. tuples and records), reference equality (e.g. object types) or some custom notion of equality (e.g. object types that implement IComparable or override Object.Equals).

In the case of multi-dimensional arrays you have spotted we're not doing any of these, which is a bug. You will currently have to write an equality function by hand for these as a workaround.

I've logged this as issue #1059 in our internal bug database. (At some point we hope to make this database accessible in some form so you'll be able to track our progress on this issue, but we haven't done that just yet).

Kind regards

Don

By on 10/21/2007 9:06 AM ()

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