The Other Prelude

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Revision as of 12:04, 21 December 2006

1 Call for Contribution

This fun project, called "The Other Prelude", and is a creative reconstruction of the standard Prelude. By disregarding history and compatibility, we get a clean sheet.

2 Naming Conventions

The principal is to make the names very readable for both beginners and category theorists (if any).

3 Guidelines

• The prelude should not contain any "projection" functions (like
  fst
  and
  snd
  . They go to the Extension module.

4 Issues

• Should alphanumeric names be preferred over symbols when defining a class?

5 The Hierarchy

• TheOtherPrelude
  - Minimalistic module.
• TheOtherPrelude.Extension
  - Convenient definitions.

6 The Code

Currently, the code is in Wiki form. If people do agree that the collaborative decisions begot something pretty, we'll have a group of files in darcs.haskell.org some time.

The imaginery Prelude as it stands,

import Prelude ()    -- hide everything
 
-- the idea is to remove 'fmap' 
-- and map :: (a -> b) -> [a] -> [b] to be a special case
 
class Functor f where
  map :: (a -> b) -> f a -> f b
 
 
-- should the Functor hierarchy proposal be adopted?
class Monad m where
  (>>=) :: m a -> (a -> m b) -> m b
  (>>) :: m a -> m b -> m b
  return :: a -> m a
  fail :: String -> m a

How to use it, as it stands,

import Prelude ()                            -- hide everything
import TheOtherPrelude                       -- get everything
import qualified TheOtherPrelude.Monad as M  -- standard convention

7 See Also

• Mathematical prelude discussion - A numeric Prelude. Could this be merged into this one?
• Prelude extensions and Prelude function suggestions - Unlike "The Other Prelude" they enhance the Prelude.
• Functor hierarchy proposal - making "Monad m" imply "Functor m"
• If-then-else - making "if" a function

Categories: Proposals | Mathematics | Code