Re: [stella] The newbie DASM #constant problem

Subject: Re: [stella] The newbie DASM #constant problem
From: KirkIsrael@xxxxxxxxxxxxx
Date: 10 Apr 2004 04:40:31 -0000
Synopsis: my preference would be a way of tagging every label
as a "memory label" or a "constant label", any memory label
with a # is a strong warning, every contant label OR NUMBER without 
a # is a strong warning.

> We had a discussion a couple weeks ago about whether the assembler could
> possibly notice and warn about the most common syntax error made by new
> (and experienced) 2600 programmers - writing LDA 5 when you mean LDA #5.
> As I was coding for the 2600 today, the solution hit me: have DASM throw a
> warning for any read from a zeropage location between 0 and $7F that uses
> a number rather than a constant reference.  In common coding practice, we
> never refer to any of the TIA registers numerically - we always use the
> constant names like CXM1FB.
> 
> LDA 5		;warning, almost certainly a mistake!
> LDA #5		;good - never warn if the # is used
> LDA CXM1FB	;good - a constant name is used
> LDA $85		;don't warn - RAM access, which is often done numerically
> 
> Of course, there's the usual debate over whether something like this
> should go into an ostensibly general-purpose assembler, but I think it's
> worthwhile implementing as an option.  I might even have a go myself once
> DASM moves to open source.
> 
> Anyone have any opinions?

The trouble is this misses stuff like 
LDA CONST_SPEED_DELTA 
Which is the one that zapped me about half the time.

I think an ideal solution would be some kind of 
(macroish?) way of tagging labels as either used for constant 
values or used as a memory location.

Also, I don't think "LDA $85" is usually indicative 
of a good programming practice...
I know I'm not the programmer with the most flair, 
(not in the "Office Space" sense of "flair" ;-) but I 
*never* do a LDA $85 and "mean it" -- that would always mean
I screwed up, I *only* reference memory locations by labels,
even when using tricky code that uses offsets and what not--
it still uses a label for the base memory location 
(and if need me, I could always define a " HEXEIGHTFIVE = $85"
or something)

But I think some syntax for specifying if a label should
be for memory or for a constant value, and assuming every
hard coded number is a constant value...that would be great.
If it was a macro, even better.

(I'm sure better programmers have a reason that they just 
 need to use memory values by number, but I don't know what 
 it is.)
 




-- 
KirkIsrael@xxxxxxxxxxxxx    http://kisrael.com
"Rationality tied to moral decency is the most powerful joint 
  instrument for good that our planet has ever known." --Michael Shermer


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