[Haskell-cafe] the complex package is hidden

[Tom Ellis]

On Sun, Sep 28, 2014 at 01:56:48PM -0700, briand at aracnet.com wrote:
> On Sun, 28 Sep 2014 21:46:22 +0100
> Tom Ellis <tom-lists-haskell-cafe-2013 at jaguarpaw.co.uk> wrote:
> 
> > On Sun, Sep 28, 2014 at 01:38:55PM -0700, briand at aracnet.com wrote:
> > > On Sun, 28 Sep 2014 20:58:42 +0100
> > > Tom Ellis <tom-lists-haskell-cafe-2013 at jaguarpaw.co.uk> wrote:
> > > > On Sun, Sep 28, 2014 at 12:55:53PM -0700, briand at aracnet.com wrote:
> > > > > surprisingly i can't seem to google an answer to this:
> > > > > 
> > > > >     Could not find module `Complex'
> > > > >     It is a member of the hidden package `haskell98-2.0.0.2'.
> > > > >     Use -v to see a list of the files searched for.
> > > > 
> >
> > So what's the error message?
> 
> yes. well it pays to read carefully.
> 
> once i fixed it in the top level module another module also be called had the wrong import, i didn't notice that at first, thought i had the same error. well i did, but in a different file.
> 
> all fixed and i'm good to go.
> 
> thanks for your help !
> 
> p.s.  is there documentation that makes it clear that Data.Complex is required ?
> 
> I'm looking at the haskell hierarchial libraries and it's not at all obvious that Complex comes under Data.  Here's the link I'm using:
> 
> http://www.haskell.org/ghc/docs/latest/html/libraries/

Glad you got it sorted!

Complex is mentioned there because it is still around for compatibility with
Haskell 98, but it's not enabled by default.  You'll also see Data.Complex
in that list.  Arguably there should be a warning on the page of the former
to use the latter instead.

Tom