On Tue, Apr 24, 2012 at 7:19 AM, Oldrine Lewis <ole...@sutron.com> wrote:
> HI,**** > > ** ** > > I understand that If I have multiple struct types, I would have to have > multiple copies of code to operate on them. I was just hoping that the > compiler would do the work for me if I made the component generic, rather > than me maintaining multiple copies of almost identical code . My > understanding of generic modules was that they make the same module work > with different data types( built-in and user-defined data types ) . > I struggling with the pedagogy of this... I'm not sure how to help you see what is happening with generics. The key is while the originating source is the same. The instantiation is different and there is actually different code that is being generated. It does NOT make the "same" module work with different data types. Take a look at how generic modules actually work... That is look at the resultant app.c Try different things and then look at the resultant app.c to see what is generated. > **** > > If a data type was type defined in a module , I assumed that you could > access it like a regular struct anywhere in the module. I now understand > that it is not the case.**** > > ** ** > > The only solution, I see for my scenario is to have multiple > (identical)modules each accepting one struct type as an argument . > If there is a block of same data, then represent that as an opaque structure that is included in each of the greater data structures. Then use a regular component that manipulates the common data. Hope this helps. > > **** > > ** ** > > Thanks,**** > > Lewis**** > > ** ** > > Hi Eric,**** > > I have multiple structures with a few common elements. The operations to > be performed on these elements are similar across all structs. The generic > module seemed to be an easy way to avoid duplicating the code**** > > ** ** > > It doesn't actually avoid duplicating the code rather it replicates the > code. Meaning every time you instantiate the generic module the entire > module is replicated in the resultant output (app.c).**** > > ** ** > > Generic modules should get used when you are doing something that is > generically the same but the details are somewhat different.**** > > ** ** > > What you are trying to do is the details are the same and you want to use > common code. That isn't what generic is for.**** > > ** ** > > From the TinyOS Programming manual...**** > > Then nesC generates two copies of the VirtualizeTimerC’s code. It does > this because different instances of Virtu- alizeTimerC might have different > types and different constants.**** > > ** ** > > VirtualizeTimerC is generic....**** > > ** ** > > **** > > ** ** > > for each struct, since the struct would be defined (typedef type) in each > module , I expected the compiler would be aware of the data type. > Thanks,**** > > Lewis**** > > **** > > *From:* Eric Decker [mailto:cire...@gmail.com] > *Sent:* Monday, April 23, 2012 11:23 PM > *To:* Oldrine Lewis > *Cc:* tinyos-help@millennium.berkeley.edu > *Subject:* Re: [Tinyos-help] Question regarding generic components**** > > **** > > **** > > On Mon, Apr 23, 2012 at 7:23 PM, Oldrine Lewis <ole...@sutron.com> wrote:* > *** > > Hi Eric,**** > > I wanted to make the module (MyModuleM ) a generic module so that it can > handle different structs. **** > > **** > > Using a generic module is not exactly a good idea.**** > > **** > > The way generic works is it replicates code. Essentially the code is > duplicated for each instance (i.e. new invocation).**** > > **** > > So if you have common pieces of a structure then you should probably > access it using a non-generic access module. That way**** > > you can still accomplish the abstraction without duplicating the code.**** > > **** > > The different structs all have some identical members. MyModuleM will > perform some generic operations **** > > **** > > calling these generic operations is fairly confusing.**** > > **** > > eric**** > > **** > > **** > > on these common members **** > > Thanks,**** > > Lewis**** > > **** > > **** > > *From:* Eric Decker [mailto:cire...@gmail.com] > *Sent:* Monday, April 23, 2012 10:13 PM > *To:* Oldrine Lewis > *Cc:* tinyos-help@millennium.berkeley.edu > *Subject:* Re: [Tinyos-help] Question regarding generic components**** > > **** > > **** > > On Mon, Apr 23, 2012 at 7:05 PM, Oldrine Lewis <ole...@sutron.com> wrote:* > *** > > Hi,**** > > **** > > Can I access the members in a user defined type inside a generic module? * > *** > > **** > > typedef struct**** > > {**** > > uint8_t m_count;**** > > }MyStruct;**** > > **** > > **** > > **** > > generic module MyModuleM(typedef type)**** > > {**** > > provides interface MyInterface;**** > > }**** > > implementation**** > > {**** > > command void MyInterface.TestStructAccess(type* t)**** > > **** > > try **** > > **** > > command void MyInterface.TestStructAccess(MyStruct* t)**** > > **** > > **** > > {**** > > t->m_count++;//I get an error here **** > > }**** > > }**** > > **** > > **** > > Thanks,**** > > Lewis**** > > **** > > > _______________________________________________ > Tinyos-help mailing list > Tinyos-help@millennium.berkeley.edu > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help** > ** > > > > **** > > **** > > -- > Eric B. Decker > Senior (over 50 :-) Researcher**** > > > > **** > > **** > > -- > Eric B. Decker > Senior (over 50 :-) Researcher**** > > > > **** > > ** ** > > -- > Eric B. Decker > Senior (over 50 :-) Researcher > > **** > -- Eric B. Decker Senior (over 50 :-) Researcher
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