[Haskell-beginners] Check constructor's field numeric value at compile time

[Dmitriy Matrosov]

Hi.

I have a type

data Interval	= Seconds Float
		| MicroSeconds Int

The Float field of data constructor Seconds should be >= 1, and Int 
field of constructor MicroSeconds should be in the range from 0 to 1000000.

How can i write this constraints so they're checked at compile time, not 
at runtime?

--
     Dmitriy Matrosov