Re: question on Cases with elements that might be strings
- To: mathgroup at smc.vnet.net
- Subject: [mg86557] Re: question on Cases with elements that might be strings
- From: dh <dh at metrohm.ch>
- Date: Thu, 13 Mar 2008 20:51:30 -0500 (EST)
- References: <frasc3$1hm$1@smc.vnet.net>
Hi Ramiro,
StringExpression can only be used with string operators. Consider e.g.:
StringMatchQ[ "s1", StringExpression["s",NumberString]]
MatchQ[ "s1", StringExpression["s",NumberString]]
as a quick fix, you could try to convert your data to a string using
ToString.
hope this helps, Daniel
ramiro wrote:
> Hi,
>
> The following is a valid pattern match:
>
> In[96]:= StringMatchQ["s1", StringExpression["s", NumberString]]
>
> Out[96]= True
>
> HOWEVER, the following does not work:
> In[89]:= Cases[{{1 -> "s1", 1}, {2 -> "s2", 2}}, {_ ->
> StringExpression["s", NumberString], _}]
>
> Out[89]= {}
>
> Even though this works:
> In[95]:= Cases[{{1 -> "s1", 1}, {2 -> "s", 2}}, {_ ->
> StringExpression["s"], _}]
>
> Out[95]= {{2 -> "s", 2}}
>
>
> How come cases does not work on ln[89]?
>
> Ramiro
>