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Initializing records and case sensitivity ??
f#

If I define a record type and initialize it like below: 

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type Whole =
    { the1 : int
      the2 : int
    }      
      
let test =
    { new  Whole
      with the1 = 1
      and  the2 = 2
    }

...then, everything is fine, but if the field names start with a capital, like below:

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type Whole =
    { The1 : int
      The2 : int
    }      
      
let test =
    { new  Whole
      with The1 = 1
      and  The2 = 2
    }


...then I get a "This construct is deprecated ..." error. What's going on here?

.

Both forms are intended to be deprecated, the fact that one is accepted is a bug.

If you want to initialize a record, just give vales to all its fields as below. The "{new..." form somewhat conflicts with object expressions in the language grammar.

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type Whole1 =
    { the1 : int
      the2 : int
    }      
      
let test1 =
    { the1 = 1
      the2 = 2
    }

type Whole =
    { The1 : int
      The2 : int
    }      
      
let test =
    { The1 = 1
      The2 = 2
    }
By on 2/12/2010 9:48 AM ()

I used the "new" syntax to solve ambiguities. Is there a new recommended way of doing this? Type constraints maybe, as in this example (in two different ways):

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type Foo =
    { The1 : int
      The2 : int
    }      
    
type Bar =
    { The1 : int
      The2 : int
    }    
      
let aFoo : Foo =
    { The1 = 1
      The2 = 2
    } 
    
let anotherFoo =
    { The1 = 1
      The2 = 2
    } : Foo
By on 2/12/2010 11:01 AM ()

Personally as a matter of style I always like qualifying the first field, as below. I expect there are a number of things you can do to make the type inference work out the desired way, though.

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type A =
    { X : int
      Y : int }
type B =
    { X : int
      Y : int }
let someA = { A.X = 3; Y = 4 }
let someB = { B.X = 3; Y = 4 }
By on 2/12/2010 12:36 PM ()

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