Message-ID: <413FB8C0.4050008@idigx.com>
Date: Wed, 08 Sep 2004 20:58:24 -0500
From: Thomas Swan <tswan@idigx.com>
User-Agent: Mozilla Thunderbird 0.7.3 (Windows/20040803)
MIME-Version: 1.0
To: olly@lfix.co.uk
Cc: Josh Berkus <josh@agliodbs.com>,
	Theo Galanakis <Theo.Galanakis@lonelyplanet.com.au>,
	pgsql-sql@postgresql.org
Subject: Re: Isnumeric function?
References: <82E30406384FFB44AFD1012BAB230B55037D056E@shiva.au.lpint.net>	
	<200409080947.17682.josh@agliodbs.com>
	<1094664017.2014.80.camel@linda>	
	<200409081048.01034.josh@agliodbs.com>
	<1094667111.2014.98.camel@linda>
In-Reply-To: <1094667111.2014.98.camel@linda>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit

Oliver Elphick wrote:

>On Wed, 2004-09-08 at 18:48, Josh Berkus wrote:
>  
>
>>Theo, Oliver,
>>
>>    
>>
>>>Any reason why you don't like  ~ '^([0-9]?)+\.?[0-9]*$' ?
>>>      
>>>
>>Yes, because it also matches "." , which is not a valid numeric value.
>>
>>    
>>
>>> ~ '^([0-9]+|[0-9]+\\.[0-9]*|[0-9]*\\.[0-9]+)$'
>>>      
>>>
>>Ah, the brute force approach ;-)
>>    
>>
>
>Nothing like using a nice big hammer!
>
>  
>
Would "^([0-9]+\\.{0,1}[0-9]*|\\.[0-9]+)$" be a little cleaner?

>>Actually, the above could be written:
>>
>>~ '^([0-9]+)|([0-9]*\\.[0-9]+)$'
>>    
>>
>
>But that doesn't allow a trailing decimal point.
>
>  
>
>>... though that still seems inelegant to me.  Is there a regex expert in the 
>>house?
>>    
>>
>
>All the elegant approaches I can think of match the empty string. There
>must be at least one digit and 0 or 1 decimal point with no other
>characters permitted.  If you use this as a constraint, you could make
>it elegant and combine it with another constraint to exclude '' and '.'.
>  
>