So here is the updated stack module. The name "CLEAR" has been changed
to "DESTROY" as suggested by Bruno. Error checking has been included.
The macro interface remains. Although a macro interface means macros,
the macros are trivial and the type safety wins here, I think. I have
renamed STACK_BASE to STACK_CURRENT_BASE because the base may be
invalidated when items are pushed onto the stack and reallocation has
to happen.
As I haven't heard anything from the FSF yet, I wouldn't mind if you
considered the following in the public domain...
#ifndef _GL_STACK_H
#define _GL_STACK_H
#include
#include
#include "assure.h"
#include "xalloc.h"
#define STACK(type)\
struct {\
type *base;\
size_t size;\
size_t allocated;\
}
#define STACK_INIT(stack)\
do\
{\
(stack).base = NULL;\
(stack).size = 0;\
(stack).allocated = 0;\
}\
while (0)
#define STACK_DESTROY(stack)\
free ((stack).base)
#define STACK_EMPTY(stack)\
((stack).size == 0)
#define STACK_CURRENT_BASE(stack)\
((stack).base)
#define STACK_PUSH(stack, item)\
do\
{\
if ((stack).size == (stack).allocated)\
(stack).base = x2nrealloc ((stack).base, &(stack).allocated,
sizeof (item)); \
(stack).base [(stack).size++] = item;\
}\
while (0)
#define STACK_POP(stack)\
(affirm (!STACK_EMPTY (stack)), (stack).base [--(stack).size])
#define STACK_DISCARD(stack)\
(affirm (!STACK_EMPTY (stack)), (--(stack).size))
#define STACK_TOP(stack)\
(affirm (!STACK_EMPTY (stack)), (stack).base[(stack).size - 1)
#define STACK_SIZE(stack)\
((stack).size)
#endif /* _GL_STACK_H */
Am So., 24. Mai 2020 um 21:26 Uhr schrieb Bruno Haible :
>
> Paul Eggert wrote:
> > I don't want to encourage programmers to supply an E with side effects, as
> > side
> > effects are trouble here.
>
> +1
>
