[Swift-devel] loops and strings

[Veronika Nefedova]

will allowing multiple assignments to the same variable be a really  
impossible thing to have in swift?

Nika

On Jul 27, 2007, at 1:24 PM, Mihael Hategan wrote:
> I see we're getting back to the same old story of the conflict between
> writing a mapper and hacking one directly in swift.
>
> This is an issue we really need to deal with. It has produced more
> discussions and hacks than any other single Swift issue.
>
> You could use an array, or we could provide a folding operator/ 
> function,
> or even a join function.
> We could also let fixed_array_mapper accept an array as a  
> parameter, so
> you would build an array with the file names and then pass it to the
> mapper.
>
> On Fri, 2007-07-27 at 11:09 -0500, Veronika Nefedova wrote:
>> I need to 'cat' together an unknown number of strings to form a
>> string, thats why I was attempting to do it inside the loop. And even
>> if I knew the number of loop cycles (say, its 68) -- are you
>> suggesting  to do it 'by hand' ?
>>
>>
>> Anyway - my main goal is not to create this string, but to map an  
>> array:
>> file whamfiles_$s[] <fixed_array_mapper;files="$wham_string">;
>>
>> Do you see a solution here?
>>
>> Thanks,
>>
>> Nika
>>
>>
>> On Jul 27, 2007, at 11:01 AM, Mihael Hategan wrote:
>>
>>> wham_string2 = @strcat(wham_string, ", wham");
>>> print(wham_string2);
>>>
>>> Variables are not variables. They are labels that are used to
>>> direct the
>>> data flow. Loops (in the sense of data looping around the same  
>>> node -
>>> picture this as a data flow graph) make no sense.
>>>
>>> On Fri, 2007-07-27 at 10:50 -0500, Veronika Nefedova wrote:
>>>> So how else then I construct a string in swift ?
>>>>
>>>>
>>>> On Jul 27, 2007, at 10:46 AM, Mihael Hategan wrote:
>>>>
>>>>> Variables in swift are single assignment. You can't assign to a
>>>>> variable
>>>>> twice. What, in your opinion, should the error message be instead
>>>>> of the
>>>>> current one?
>>>>>
>>>>> On Fri, 2007-07-27 at 10:22 -0500, Veronika Nefedova wrote:
>>>>>> I am not sure if its possible to do string operations inside the
>>>>>> loop
>>>>>> in swift?
>>>>>> I have a versy simple test code that doesn't work no matter what.
>>>>>> Obviously, I am missing something.
>>>>>> This is the code:
>>>>>>
>>>>>> file fls[]<filesys_mapper;pattern="*.prt",location=".">;
>>>>>> string wham_string = "#";
>>>>>> foreach prt_file in fls
>>>>>> {
>>>>>>        wham_string = @strcat (wham_string, ", wham");
>>>>>>        print (wham_string);
>>>>>> }
>>>>>> print (wham_string);
>>>>>>
>>>>>>
>>>>>> basically I expect to have this as an output:
>>>>>> #,wham,wham,wham,wham,... (its a test code (-;)
>>>>>>
>>>>>> instead I have these errors:
>>>>>>
>>>>>> wham_string is already assigned with a value of #
>>>>>> wham_string is already assigned with a value of #
>>>>>>          vdl:assign @ test.kml, line: 46
>>>>>>          vdl:mains @ test.kml, line: 39
>>>>>> Caused by: java.lang.IllegalArgumentException: wham_string is
>>>>>> already
>>>>>> assigned with a value of #
>>>>>>          at org.griphyn.vdl.mapping.AbstractDataNode.setValue
>>>>>> (AbstractDataNode.java:255)
>>>>>>          at org.griphyn.vdl.karajan.lib.Assign.function
>>>>>> (Assign.java:70)
>>>>>> <snip>
>>>>>>
>>>>>>
>>>>>> In any case -- if I can't construct the string by using the  
>>>>>> loop -
>>>>>> how else could it be done?
>>>>>>
>>>>>> I use the constructed string then to map an array (I understand I
>>>>>> can't map individual array elements):
>>>>>>
>>>>>> file whamfiles_$s[]  
>>>>>> <fixed_array_mapper;files="$wham_string">; //it
>>>>>> was in the wrapper script before)
>>>>>>
>>>>>>
>>>>>> Nika
>>>>>>
>>>>>> _______________________________________________
>>>>>> Swift-devel mailing list
>>>>>> Swift-devel at ci.uchicago.edu
>>>>>> http://mail.ci.uchicago.edu/mailman/listinfo/swift-devel
>>>>>>
>>>>>
>>>>
>>>
>>
>