On Jun 14, 2008, at 12:42 PM, Olin Lathrop wrote:

>> Is there a reference available that spells this out
>> clearly enough that a studious beginner can understand it
>> well and get it right?
>
> Yes, the MPASM/MPLIB/MPLINK manual.  In this case the chapter  
> "Directive
> Language".  All the directives, including #define, CBLOCK, and RES are
> individually described in detail.  That's where I learned it from.

While I don't doubt that the individual directives are "described in  
detail" in the MPASM manual, I *DO* doubt that the descriptions are  
sufficient for a beginner to really understand the differences  
between constants, string substitutions, macros, variables, reserved  
storage, and literals (and who knows what else.)  That sort of  
understanding generally has to come from having dealt with several  
different languages and different assemblers, struggling with the  
differences in concepts between C's "#define", "const", and "enum" vs  
Pascal's "const" and "set."  A compiler class MIGHT help, but they  
tend to focus on parsing whichever style of language is currently  
popular...

It doesn't help that C's capabilities in this area are primitive, or  
that mpasm combines typical assembler syntax with some C capabilities  
thrown in...

I suppose that a write-up describing the basic principles would be  
possible (with examples from various languages!)  I haven't seen one;  
I'm not even sure what it would be called...

BillW

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