AW: How trim: Bug in RegExp engine

[Dave Cragg]

On 23 Oct 2005, at 11:03, Thomas Fischer wrote:

> Hi,
>
> Wouter is right:
>
>
>> It is indeed elegant, but a condition check is necessary here as it
>> will remove the first word + the space(s) if there is no space at the
>> start of the line.
>>
>>
>>> "        The cat sat on the mat.         "
>>>
>
>
>> But if no space in front the result is
>>
>> "cat sat on the mat.         "
>>
>>
>
> This is actually true -- and a serious bug in Revolution's RegExp  
> engine.
>
> The Regular Expression Syntax reference states:
>
> ^ matches the following character at the beginning of the string
> ^A matches "ABC" but not "CAB"
>
> * matches zero or more occurrences of the preceding character or  
> pattern
>
> I assumed that Revolution would do what it promised and didn't  
> check this.
>
> Try
> answer replaceText("A C","^ *","")
> I get "C", which obviously is not correct.
> If I remove the "*", I get "A C"

This may be a bug. (I'm not sure.)

But the following will work:

answer replaceText("A C","^ +","")

I.e. match "at least one" occurrence of a space, which is what is  
intended.


Cheers
Dave