| syntax for calling parent class _overloadPlus method [message #93105] |
Thu, 28 April 2016 06:01  |
Markus Schmassmann
Messages: 129
Registered: April 2016
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Senior Member |
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i'm trying to overload operators for my subclass of idl_variable, but
don't find the correct syntax for calling the parent classes' operator
function.
How do i have to correct the line below marked ';problem' without using
'left+right'?
i guess i have to put something like XXX.idl_variable::_overload...
but what would then be XXX?
---
pro sandbox__define
struct={sandbox, $
inherits idl_variable, $
reps: ptr_new() $
}
end
function sandbox::Init, array, reps
; a bit of code
void=self.idl_variable::init()
void=self.idl_variable::set_value(array)
*self.reps=reps
return, 1
end
function sandbox::_overloadPlus, left, right
; some code
out=idl_variable::_overloadPlus(left,right) ;problem
; some more code
return, out
end
---
PS: Sorry, stupid question of a beginner, but i failed to find the
solution elsewhere.
PPS: There may be more errors, but the rest at least compiles.
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| Re: syntax for calling parent class _overloadPlus method [message #93113 is a reply to message #93105] |
Thu, 28 April 2016 13:35  |
Michael Galloy
Messages: 1114
Registered: April 2006
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Senior Member |
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On 4/28/16 7:01 AM, Markus Schmassmann wrote:
> i'm trying to overload operators for my subclass of idl_variable, but
> don't find the correct syntax for calling the parent classes' operator
> function.
>
> How do i have to correct the line below marked ';problem' without using
> 'left+right'?
> i guess i have to put something like XXX.idl_variable::_overload...
> but what would then be XXX?
>
> ---
> pro sandbox__define
> struct={sandbox, $
> inherits idl_variable, $
> reps: ptr_new() $
> }
> end
>
> function sandbox::Init, array, reps
> ; a bit of code
> void=self.idl_variable::init()
> void=self.idl_variable::set_value(array)
> *self.reps=reps
> return, 1
> end
>
> function sandbox::_overloadPlus, left, right
> ; some code
> out=idl_variable::_overloadPlus(left,right) ;problem
> ; some more code
> return, out
> end
> ---
>
> PS: Sorry, stupid question of a beginner, but i failed to find the
> solution elsewhere.
> PPS: There may be more errors, but the rest at least compiles.
In general, you would use something like the following to call a
parent's implementation:
out = self->IDL_Variable::overloadPlus(left, right)
You can use the . notation you used in ::init as well:
out = self.IDL_Variable::overloadPlus(left, right)
But, in your case, you are calling some methods that don't exist. As
far as I can tell, there are no IDL_Variable::init,
IDL_Variable::set_value, and IDL_Variable::_overloadPlus methods.
Mike
--
Michael Galloy
www.michaelgalloy.com
Modern IDL: A Guide to IDL Programming (http://modernidl.idldev.com)
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| Re: syntax for calling parent class _overloadPlus method [message #93120 is a reply to message #93113] |
Fri, 29 April 2016 02:45 |
Markus Schmassmann
Messages: 129
Registered: April 2016
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Senior Member |
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On 04/28/2016 10:35 PM, Michael Galloy wrote:
> On 4/28/16 7:01 AM, Markus Schmassmann wrote:
>> i'm trying to overload operators for my subclass of idl_variable, but
>> don't find the correct syntax for calling the parent classes' operator
>> function.
>>
>> How do i have to correct the line below marked ';problem' without using
>> 'left+right'?
>> i guess i have to put something like XXX.idl_variable::_overload...
>> but what would then be XXX?
>>
>> ---
>> pro sandbox__define
>> struct={sandbox, $
>> inherits idl_variable, $
>> reps: ptr_new() $
>> }
>> end
>>
>> function sandbox::Init, array, reps
>> ; a bit of code
>> void=self.idl_variable::init()
>> void=self.idl_variable::set_value(array)
>> *self.reps=reps
>> return, 1
>> end
>>
>> function sandbox::_overloadPlus, left, right
>> ; some code
>> out=idl_variable::_overloadPlus(left,right) ;problem
>> ; some more code
>> return, out
>> end
>> ---
>>
>> PS: Sorry, stupid question of a beginner, but i failed to find the
>> solution elsewhere.
>> PPS: There may be more errors, but the rest at least compiles.
>
> In general, you would use something like the following to call a
> parent's implementation:
>
> out = self->IDL_Variable::overloadPlus(left, right)
>
> You can use the . notation you used in ::init as well:
>
> out = self.IDL_Variable::overloadPlus(left, right)
>
> But, in your case, you are calling some methods that don't exist. As
> far as I can tell, there are no IDL_Variable::init,
> IDL_Variable::set_value, and IDL_Variable::_overloadPlus methods.
>
> Mike
when searching for the definition of the variable class i found a file
idl_variable__define.pro in the following path:
/opt/idl/idl_local/pub_domain/ssw/gen/idl/clients/rpc/
(i don't maintain that file tree)
it does have an ::init & ::setvalue function.
As for the _overloadPlus, i may apparently erred in assuming
http://www.harrisgeospatial.com/docs/Overloadable_Operators. html
applies also to variables, i assumed them not beeing mentioned in the
__define file meant they were implemented in C but still could be
accessed as i wanted.
Then let me rephrase the question:
What class(es) should i use as parent class, if i want to create a
class, that during initialisation or initial set_value accepts an array
and a repetition pattern, and afterwards should behave as if the
sandboxMember has been expanded from the array & pattern using a
combination of rebin,reform,transpose...
sandbox(indgen(1,10),[40, 1,60]) should behave the same as
rebin(indgen(1,10),[40,10,60]), but only use the memory of indgen(10)
and an array ulong[8] and run faster. The operators themselves when not
operating on trivial cases will have to be implemented in C.
i want to be able to pass my sandboxMembers to foreign code that should
not realize it has not been passed an ordinary array. It will not be a
small thing to do, but if done right should increase idl performance
quite a bit.
PS: sorry for the double-post before
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| Re: syntax for calling parent class _overloadPlus method [message #93161 is a reply to message #93120] |
Tue, 03 May 2016 10:05 |
Michael Galloy
Messages: 1114
Registered: April 2006
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Senior Member |
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On 4/29/16 3:45 AM, Markus Schmassmann wrote:
> when searching for the definition of the variable class i found a file
> idl_variable__define.pro in the following path:
> /opt/idl/idl_local/pub_domain/ssw/gen/idl/clients/rpc/
> (i don't maintain that file tree)
> it does have an ::init & ::setvalue function.
I actually have an IDL_Object class in my library as well. It is useful
if I want the object to have overloaded operators when running in IDL
8.0+, but still compile and is usable (without the operators) when
running on less than IDL 8.0.
> As for the _overloadPlus, i may apparently erred in assuming
> http://www.harrisgeospatial.com/docs/Overloadable_Operators. html applies
> also to variables, i assumed them not beeing mentioned in the __define
> file meant they were implemented in C but still could be accessed as i
> wanted.
From the docs for IDL_Object:
> This class serves as an interface class for other classes. There is
never a need to instantiate an IDL_Object class directly.
What I understand this to mean, is that there is no implementation at
all of IDL_Object, it is just a definition which marks an object as
possibly having operator overloaded methods. I thought there was
something more in the docs about this, but I couldn't find it.
> Then let me rephrase the question:
>
> What class(es) should i use as parent class, if i want to create a
> class, that during initialisation or initial set_value accepts an array
> and a repetition pattern, and afterwards should behave as if the
> sandboxMember has been expanded from the array & pattern using a
> combination of rebin,reform,transpose...
> sandbox(indgen(1,10),[40, 1,60]) should behave the same as
> rebin(indgen(1,10),[40,10,60]), but only use the memory of indgen(10)
> and an array ulong[8] and run faster. The operators themselves when not
> operating on trivial cases will have to be implemented in C.
>
> i want to be able to pass my sandboxMembers to foreign code that should
> not realize it has not been passed an ordinary array. It will not be a
> small thing to do, but if done right should increase idl performance
> quite a bit.
>
> PS: sorry for the double-post before
You will have to inherit from IDL_Object to get operator overloading,
but you will have to implement all code yourself, you will get nothing
from IDL_Object.
Mike
--
Michael Galloy
www.michaelgalloy.com
Modern IDL: A Guide to IDL Programming (http://modernidl.idldev.com)
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