Re: Repeated :info giving different results

On Mon, Mar 21, 2005 at 09:01:19AM -0000, Simon Peyton-Jones wrote:
> The trouble is that instance declarations could be in *any* module. So
> at the moment GHC just reports the instances it knows about.
> 
> As time goes on, it knows about more modules, so it may report more
> instances.
> 
> I agree that it's odd that simply reporting one lot makes it know about
> more!
> And I don't claim that this is desirable behaviour.  It'd be better if
> you saw all the instance declarations that can be written in the current
> scope using unqualified names.  I'll file this as a bug.
> 
> Yell if it's hurting you; otherwise it'll be low priority.
> 
> Simon

It's not hurting me, though it gave me quite a puzzled look for a
while :)

It would however probably be a good idea to add a note about it
to the docs:

--- ghci.xml.old        Tue Mar 22 21:38:18 2005
+++ ghci.xml    Tue Mar 22 23:44:36 2005
@@ -953,7 +953,13 @@
          <replaceable>name</replaceable> is a function, then its type
          will be printed.  If <replaceable>name</replaceable> has
          been loaded from a source file, then GHCi will also display
-         the location of its definition in the source.</para>
+         the location of its definition in the source.
+         Since version 6.4, information about instances
+         (that are currently in scope) will also be given.
+         Note however that it's not always easy to figure out what GHCi
+         considers to be "in scope", and that even the :info command may
+         change what's in scope. This is a bug - though low priority - and
+         filed away as bug #1167383</para>
        </listitem>
       </varlistentry>
 
Which will probably need minor language/clarity/xml fixes.

Cheers,
Remi

-- 
Nobody can be exactly like me. Even I have trouble doing it.