How to find the offset of the first character in a string that's not a tab?

[Ken Ray]

> On Jan 21, 2021, at 8:36 AM, Keith Clarke via use-livecode <use-livecode at lists.runrev.com> wrote:
> 
> Thanks Brian. I looked at matchChunk in the dictionary & it seems to return a boolean, rather than the offset. 

The boolean is just whether or not the matchChunk operation was successful; you need to provide variables for the start and end character offsets in the function call:

if matchChunk(myString,"([^\t])",tStart,tEnd) then
  put "The offset to the first non-tab character is:" && tStart
else
  -- matchChunk had an error because the regex was bad or something
end if

I know you've moved on, but just for the record...

:D


Ken Ray
Sons of Thunder Software, Inc.
Email: kray at sonsothunder.com
Website: https://www.sonsothunder.com


> 
> Thanks all - I’ve stopped trying to find the syntax for ‘find any char but this’ in offset and instead, taken Dick’s advice to iterate through the chars and count the loops until char <> tab. :)
> Best,
> Keith     
> 
>> On 21 Jan 2021, at 14:03, Brian Milby via use-livecode <use-livecode at lists.runrev.com> wrote:
>> 
>> You could also use matchChunk with a regular expression that excludes the tab character.
>> 
>> Sent from my iPhone
>> 
>>> On Jan 21, 2021, at 7:14 AM, Keith Clarke via use-livecode <use-livecode at lists.runrev.com> wrote:
>>> 
>>> Ah yes indeed, I’d forgotten I could test with 'put not(tab)’ in the message box - that certainly proves the syntax was wrong! :-)
>>> Best,
>>> Keith
>>> 
>>>>> On 21 Jan 2021, at 10:49, Dick Kriesel via use-livecode <use-livecode at lists.runrev.com> wrote:
>>>>> 
>>>>> 
>>>>> 
>>>>>> On Jan 21, 2021, at 2:34 AM, Keith Clarke via use-livecode <use-livecode at lists.runrev.com> wrote:
>>>>> 
>>>>> I was just keen to understand why offset wasn’t happy with the ‘not(tab)’ in this instance.
>>>> 
>>>> expression "not(tab)" evaluates to true, which doesn’t serve your purpose
>>>> 
>>>> — Dick
>>>> 
>>>> 
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