From nathan at acceleration.net  Fri Mar  6 17:10:10 2009
From: nathan at acceleration.net (Nathan Bird)
Date: Fri, 06 Mar 2009 12:10:10 -0500
Subject: [cl-containers-devel] darcs patch: When searching for an item in a
	bst, make sure that th...
Message-ID: <E1LfdYo-00078H-3P@sekhmet.acceleration.net>

Fri Mar  6 11:52:50 EST 2009  Nathan Bird <nathan at acceleration.net>
  * When searching for an item in a bst, make sure that the node isn't a placeholder and actually has an element
-------------- next part --------------
A non-text attachment was scrubbed...
Name: when-searching-for-an-item-in-a-bst_-make-sure-that-the-node-isn_t-a-placeholder-and-actually-has-an-element.dpatch
Type: text/x-darcs-patch
Size: 428 bytes
Desc: A darcs patch for your repository!
URL: <https://mailman.common-lisp.net/pipermail/cl-containers-devel/attachments/20090306/12c1bf48/attachment.bin>

From nathan at acceleration.net  Fri Mar  6 19:51:43 2009
From: nathan at acceleration.net (Nathan Bird)
Date: Fri, 06 Mar 2009 14:51:43 -0500
Subject: [cl-containers-devel] darcs patch: When searching for an item
 in a bst, make sure that th...
In-Reply-To: <E1LfdYo-00078H-3P@sekhmet.acceleration.net>
References: <E1LfdYo-00078H-3P@sekhmet.acceleration.net>
Message-ID: <49B17ECF.6030605@acceleration.net>

On 3/6/2009 12:10 PM, Nathan Bird wrote:
> Fri Mar  6 11:52:50 EST 2009  Nathan Bird<nathan at acceleration.net>
>    * When searching for an item in a bst, make sure that the node isn't a placeholder and actually has an element
>    
The point of this is that because the red black tree has empty nodes as 
placeholders we need to test for that. Without this searching a red 
black tree for an element it doesn't contain doesn't return null, but 
errors.

 > (containers:item-at (containers:make-container 
'containers:red-black-tree) 1)

Alternatively to testing the element slot directly, there appears to be 
a node-empty-p function that might be more appropriate.



From gwking at metabang.com  Fri Mar  6 22:03:58 2009
From: gwking at metabang.com (Gary King)
Date: Fri, 6 Mar 2009 17:03:58 -0500
Subject: [cl-containers-devel] darcs patch: When searching for an item
	in a bst, make sure that th...
In-Reply-To: <49B17ECF.6030605@acceleration.net>
References: <E1LfdYo-00078H-3P@sekhmet.acceleration.net>
	<49B17ECF.6030605@acceleration.net>
Message-ID: <4F11F459-895E-4209-8098-3008EBA76E15@metabang.com>

Thanks Nathan,

I'll look try at this over the weekend.


On Mar 6, 2009, at 2:51 PM, Nathan Bird wrote:

> On 3/6/2009 12:10 PM, Nathan Bird wrote:
>> Fri Mar  6 11:52:50 EST 2009  Nathan Bird<nathan at acceleration.net>
>>   * When searching for an item in a bst, make sure that the node  
>> isn't a placeholder and actually has an element
>>
> The point of this is that because the red black tree has empty nodes  
> as
> placeholders we need to test for that. Without this searching a red
> black tree for an element it doesn't contain doesn't return null, but
> errors.
>
>> (containers:item-at (containers:make-container
> 'containers:red-black-tree) 1)
>
> Alternatively to testing the element slot directly, there appears to  
> be
> a node-empty-p function that might be more appropriate.
>
> _______________________________________________
> cl-containers-devel mailing list
> cl-containers-devel at common-lisp.net
> http://common-lisp.net/cgi-bin/mailman/listinfo/cl-containers-devel

--
Gary Warren King, metabang.com
Cell: (413) 559 8738
Fax: (206) 338-4052
gwkkwg on Skype * garethsan on AIM * gwking on twitter








From nathan at acceleration.net  Sat Mar  7 19:16:35 2009
From: nathan at acceleration.net (Nathan Bird)
Date: Sat, 07 Mar 2009 14:16:35 -0500
Subject: [cl-containers-devel] darcs patch: When searching for an item
 in a bst, make sure that th...
In-Reply-To: <4F11F459-895E-4209-8098-3008EBA76E15@metabang.com>
References: <E1LfdYo-00078H-3P@sekhmet.acceleration.net>
	<49B17ECF.6030605@acceleration.net>
	<4F11F459-895E-4209-8098-3008EBA76E15@metabang.com>
Message-ID: <49B2C813.8050505@acceleration.net>

On 3/6/2009 5:03 PM, Gary King wrote:
> Thanks Nathan,
>
> I'll look try at this over the weekend.
>
>
> On Mar 6, 2009, at 2:51 PM, Nathan Bird wrote:
>
>> On 3/6/2009 12:10 PM, Nathan Bird wrote:
>>> Fri Mar  6 11:52:50 EST 2009  Nathan Bird<nathan at acceleration.net>
>>>   * When searching for an item in a bst, make sure that the node 
>>> isn't a placeholder and actually has an element
>>>
>> The point of this is that because the red black tree has empty nodes as
>> placeholders we need to test for that. Without this searching a red
>> black tree for an element it doesn't contain doesn't return null, but
>> errors.
>>
>>> (containers:item-at (containers:make-container
>> 'containers:red-black-tree) 1)
>>
>> Alternatively to testing the element slot directly, there appears to be
>> a node-empty-p function that might be more appropriate.
I made a patch that uses the node-empty-p function instead, as well as a 
patch that adds a bunch of tests on the red-black and binary-search 
trees. Removed the tests/misc.lisp file in which all the code was 
commented out; what was in there is now one of the tests in trees.lisp 
(fixed up a bit).


-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: trees.dpatch
URL: <https://mailman.common-lisp.net/pipermail/cl-containers-devel/attachments/20090307/135aa69b/attachment.ksh>