RE: [Haskell-cafe] namespacing?

I'm appreciating the feedback. I discovered where I was going wrong. The library I was using allowed me to import a module, which in turn allowed me to use functions from other modules. So even though I could use func directly I couldn't use B.func because I hadn't explicitly imported B. I find that interesting. I would have thought that if I hadn't explicitly imported a module I would either be forced to use the qualified name, not use the function at all, or at the very least be allowed to qualify the name. thanks Jason

-------- Original Message -------- Subject: Re: [Haskell-cafe] namespacing? From: "Duncan Coutts" Date: Wed, December 08, 2004 10:12 am To: azrael@demonlords.net Cc: haskell-cafe@haskell.org

On Wed, 2004-12-08 at 07:58 -0700, azrael@demonlords.net wrote:

...

I've got a general new person type question.

I understand that I can hide a function in a module that I am importing if it conflicts with another identical function name.

But if the situation arises that I would like to use two identically named functions from two different modules is there anyway for me to specify that I want to use the function from module A rather then the function from module B.

module C where

import A import qualified A (foo)

import B import qualified B (foo)

... A.foo ...

... B.foo ...

There are actually several options here, you can import modules only qualified, then every value from that module needs to be qualified. Some modules are designed to be used this way, see for example Data.HashTable http://www.haskell.org/ghc/docs/latest/html/libraries/base/Data.HashTable.ht... (and people are encouraged to write new modules in this style).

If it's just one or two values that clash then the example above is good, ie import the whole thing unqualified and just qualify the one or two names that clash.

You can even give short names to modules you import, eg:

import qualified System.Gnome.GConf as Config

now I can say Config.get rather than System.Gnome.GConf.get

Hope this helps.

Duncan