[Haskell-beginners] some terminology

Michael P Mossey mpm at alumni.caltech.edu
Wed Aug 12 21:59:16 EDT 2009


I was looking at some code, saw a variable x, and said to myself, "Ah that 
variable is a monad." Then I realized "Monad" is the name of a type class. So 
maybe x should be called "an instance of a Monad." I think the word "instance" 
in this case is OO-like; but in Haskell "instance" refers to a type that is an 
instance of a type class. Or maybe it can refer to both? And Monad is a type 
class, not a type. Maybe I need the phrase "monadic type" to refer to an 
instance of a type class. So maybe x is just "a variable of a monadic type"?

Thanks,
Mike


More information about the Beginners mailing list