[prev in list] [next in list] [prev in thread] [next in thread] 

List:       haskell-cafe
Subject:    Re: [Haskell-cafe] Haskell Propeganda
From:       wren ng thornton <wren () freegeek ! org>
Date:       2008-08-29 8:57:14
Message-ID: 48B7B9EA.9060104 () freegeek ! org
[Download RAW message or body]

Richard A. O'Keefe wrote:
> 
> On 28 Aug 2008, at 8:34 am, Aaron Tomb wrote:
>> What type safety buys you, in my mind, is that Nothing is only a valid 
>> value for explicit Maybe types. In cases where you don't use Maybe, 
>> the "null" situation just can't occur. In languages with null 
>> pointers, any pointer could possibly be null.
> 
> This is not true of Eiffel.
> The ECMA Eiffel standard has
>     ?T    either a void reference or a reference to an instance of T
>     !T    a reference to an instance of T
>      T    same as !T in ECMA Eiffel; used to be same as ?T
> 
> I suppose you could call the detachable type ?T an *implicit* Maybe.
> Needless to say, the switch in semantics of undecorated T helped to
> fork the Eiffel community...


Just because the devil needs more advocacy... there are safer dialects 
of C that have non-nullable pointers in addition to the standard 
variety. Cyclone[1] comes to mind, there are others.

In so far as propaganda goes, imperative programming is ugly, unsafe, 
and evil, but it is getting better. Blanket statements about their 
failings tend toward falsity as they keep adopting things from the 
functional world.

[1] http://www.cs.bu.edu/groups/ibench/presentations/2003-04-10.pdf

-- 
Live well,
~wren
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
[prev in list] [next in list] [prev in thread] [next in thread]