Re: [Haskell-cafe] Newbie Q: GHCi: Where “List” module is imported from?
jules at jellybean.co.uk
Fri Feb 16 18:01:02 EST 2007
Dmitri O.Kondratiev wrote:
> Where exactly "the Ord instance for lists is defined in the Prelude"?
Depends slightly on your compiler, but you will find that some of the
prelude has source, and some of the prelude is inevitably not written in
haskell (the type system has to be bootstrapped somehow). There is
special language support for lists although it is essentially just
syntax: you could define a list by hand, but you wouldn't get the cute
[1,2,3,4] style syntax for them (you'd have to write 1:2:3:4:Empty or
> It seems that Prelude treats "list" as a built-in type same as a
> "tuple" type. Also Prelude does not know anything about Data.List
> type, right?
Data.List isn't a type. It's a module. (I.e. a bunch of functions and
types). Data.List just happens to define some useful functions to use on
> As I understand in Haskell to be an instance of a class type must be
> declared as:
> instance ClassName TypeName
> where then declaration:
> instance Ord 
> can be found?
In the source for the prelude.
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