Re: Variable scoping for local variable in functions

Hi Oli,
I don't think a variable used as the return value has any special
status inside the function, so the same rules apply as for any other
variable.
  -dave

On Nov 13, 2009, at 1:14 PM, <Oliver.Fuhrer@meteoswiss.ch> wrote:

> Dave,
>
> Great! I will wait for the next release. For the moment I am using a
> workaround with deletes at the end of the functions to clean away
> the variables within the function!
>
> BTW: Should the return value of a function also be declared as
> "local" or not?
>
> Cheers,
> Oli
>
>
> -----Original Message-----
> From: David Brown [mailto:dbrown@ucar.edu]
> Sent: Fri 11/13/2009 7:21 PM
> To: Fuhrer Oliver
> Cc: ncl-talk@ucar.edu
> Subject: Re: Variable scoping for local variable in
> functions
>
> Hi Oli,
> I am a little surprised at the fact you are getting different results
> for functions and procedures, because
> I thought the problem existed for both. At any rate, this problem was
> reported earlier this year by Melissa
> Bukowsky and was fixed with a check-in (that applied both to functions
> and procedures) on 9 September, 2009.
> Running your code with the development version of NCL gives (as
> complete output):
> (0) this is test1
> (0) this is test1
> (0) this is test2
> (0) this is test2
>
> If you would like the new code let us know.
> -dave
>
> On Nov 13, 2009, at 5:49 AM, <Oliver.Fuhrer@meteoswiss.ch> <Oliver.Fuhrer@meteoswiss.ch
>> wrote:
>
>> Hi ncl-talk,
>>
>> It seems that there is a strange quirk for local variables in
>> functions
>> which makes that they remain somehow globally defined in spite of
>> being
>> declared as local. Upon second entry the isvar() function returns
>> true
>> for such a variable but any reference to it give "variable
>> undefined".
>> This seems to be only the case for functions and not procedures.
>> Here's
>> an illustrative example which bugs and - in my humble opinion -
>> should
>> not.
>>
>> Any ideas?
>> Oli
>>
>> ---------- script ------------
>>
>> undef("test1")
>> procedure test1 ( )
>> local dummy1
>> begin
>> print("this is test1")
>> if (isvar("dummy1")) then
>> print("deleting dummy1")
>> delete(dummy1)
>> end if
>> dummy1 = 3
>> end
>>
>> undef("test2")
>> function test2 ( )
>> local dummy2
>> begin
>> print("this is test2")
>> if (isvar("dummy2")) then
>> print("deleting dummy2")
>> delete(dummy2)
>> end if
>> dummy2 = 3
>> return(4)
>> end
>>
>> ; first testing subroutine
>> test1( )
>> test1( )
>>
>> ; now testing function
>> a = test2( )
>> b = test2( )
>>
>> ---------- result ------------
>>
>>> ncl test6.ncl
>> Copyright (C) 1995-2009 - All Rights Reserved
>> University Corporation for Atmospheric Research
>> NCAR Command Language Version 5.1.1
>> The use of this software is governed by a License Agreement.
>> See http://www.ncl.ucar.edu/ for more details.
>> (0) this is test1
>> (0) this is test1
>> (0) this is test2
>> (0) this is test2
>> (0) deleting dummy2
>> fatal:Variable (dummy2) is undefined
>> fatal:Execute: Error occurred at or near line 20 in file test6.ncl
>>
>> fatal:Execute: Error occurred at or near line 32 in file test6.ncl
>>
>>
>>
>> ________________________________________
>>
>> Oliver Fuhrer
>> Numerical Models
>>
>> Federal Departement of Home Affairs FDHA
>> Federal Office of Meteorology and Climatology MeteoSwiss
>>
>> Kraehbuehlstrasse 58, P.O. Box 514, CH-8044 Zurich, Switzerland
>>
>> Tel. +41 44 256 93 59
>> Fax +41 44 256 92 78
>> oliver.fuhrer@meteoswiss.ch
>> www.meteoswiss.ch - First-hand information
>>
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>
>

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Received on Fri Nov 13 13:21:51 2009