C18 pseudo variables

Question

I'm looking for a way to make Jalv2-like pseudo variables in C using the C18 compiler. A pseudo variable is something that acts like a variable but actually is a function.

In Jalv2, it's possible to make a pseudo variable like this:

function the_var'get() return byte is
    -- some code
end function

procedure the_var'set(byte in value) is
    -- some code
end procedure

Now one can read and write to the_var, while actually those functions are executed:

the_var = 0x40         -- actually executes the_var'set(0x40)
doSomething(the_var)   -- actually executes doSomething(the_var'get)

Is there something similar for C?

It sounds like you are asking for "getters and setters" in C. No, this is not possible. — Dietrich Epp, Apr 22 '13 at 08:43
@DietrichEpp that's too bad - but can you make that an answer? — , Apr 22 '13 at 08:45
You could do that in C++ and use the IAR C++ compiler for PIC18. — zakinster, Apr 22 '13 at 08:46
@angelatlarge assignment operator and implicit conversion operators overloads. — zakinster, Apr 22 '13 at 08:49
@zakinster perhaps you could make that an answer? It's a nice alternative — , Apr 22 '13 at 08:51
*"I want feature X, which C doesn't have, but I want to program in C. How do I get feature X in C?"* You don't want to program in C. Use a programming language that has feature X. — autistic, Apr 22 '13 at 09:18
@modifiablelvalue I didn't know yet if C the feature had, so I asked. — , Apr 22 '13 at 09:18

score 3 · Accepted Answer · answered Apr 22 '13 at 08:46

No, it's not possible with C. It's not even possible with the preprocessor. The = operator always does the exact same thing in C, and there are no ways to customize it.

If you want to do things like that, you'll have to pick a different language. Like C++, for example, which lets you override operator = (for a setter) and operator int (for a getter).

C18 pseudo variables

1 Answers1