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Inheriting from ICompare
f#

This is probably another really stupid question, but I'm having a tough time trying to make my class implement ICompare for some reason.

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type Foo = 

  
  class

    
    val num : int

    
    new (i : int) as this = { num = i }

  
  end

  
  with

    
    member this.Comparer(x, y) = compare x.num y.num

  
  end

This gives a rather mysterious error message "This lookup uses a depreciated feature, where a class type is inferred from the use of a class field label. Use a type annotation to make it clear which class the field comes from." If I try adding an annotation to x or y, it complains about an unspecified syntax error.

Strangely enough I haven't been able to find an F# example written in this style, so I'm wondering whether I'm thinking about objects/classes in entirely the wrong way here. If there is somewhere that documents this in detail, let me know, as I'm not making progress looking at the F# manual and language specification.

Thanks!

.

You can type constrain x and y as follows.

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type Foo = 

  class

    val num : int

    new (i : int) as this = { num = i }

  end

  with

    member this.Comparer((x:Foo),(y:Foo)) = compare x.num y.num

  end
By on 10/13/2006 7:27 AM ()

Ah, I had been thrown off by the fact that 

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 this.Comparer(x:Foo, y:Foo)

was a parse error. Thanks!

By on 10/13/2006 7:33 AM ()

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