Re: Loops (was Re: do { quit; } else { })

On Wed, 23 Apr 2025 11:15:01 +0100
bart <bc@freeuk.com> wibbled:

IMV, macros generally are a bad idea. They are especially bad with how
they are implemented in C:

C macros do essentially 4 different things:
1) Provide a way to pass compilation data directly into the code via compiler
   switches and #ifdef
2) Allow conditional compilation for different OS's
3) Allow repeating blocks of code to be compacted into a single macro when
   having a function instead would be more complicated and/or inefficient.
4) An alternative to inline functions. Probably the least useful.

* Their implementation is complex and poorly defined.

Maybe to you.

* Compiler error messages can get weird and confusing

If you think C errors are confusing try C++ with template errors.

* They cause problems for tools such as smart editors

Any "smart" editor that can't cope with macros isn't smart.

* Macros don't obey normal scope rules.

They're not supposed to.

* Macro solutions tend to be ugly and tacky (see X-macros)

So can any code.

* Macro expansion can do too much:
>
   #define length 200
   #define width 100
>
   struct {char* str; int length;} s;
   s.length = 0;        // oops!

So what? You'd get a compilation error.