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private records?
f#classes

Are constructed classes the correct (in F# idioms) way to implement OCaml-"type" private records?
Certainly, i can have:

type 'a range =
{ start : 'a;
stop : 'a;
}
with
static member make x y =
if x > y then failwith "backward range"
else {start = x; stop = y }
end

but there is no method (to my knowledge) of making 'make' the default and required constructor for 'a range types. therefore i have to use a constructed class:

type 'a range(start: 'a, stop : 'a) =
do if start > stop then failwith "backward range"
member x.start = start;
member x.stop = stop;

? thank you.

.

Ok, now my brain is leaking. the first instance compiles and you can do this:

> Util.range<string>.make 4.5 10.0 ;;
val it : float Util.range = {start = 4.5;
stop = 10.0;}

from the interpreter.

By on 11/28/2008 10:01 AM ()

Your static method 'make' method on range<'a> has type ('b -> 'b -> range<'b>). You can add explicit type annotations (e.g. (x : 'a)) if you want to do what I think you want to do.

There isn't any way to do the 'private constructor' or otherwise force the check when constructing records, if you want to do that, switch to a class.

By on 11/28/2008 10:16 AM ()

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