libcdsb/src/stack.c

123 lines
2.1 KiB
C

/* This software is licensed by the MIT License, see LICENSE file */
/* Copyright © 2022 Gregory Lirent */
#include <stdarg.h>
#include <stdlib.h>
#include "__internal/include.h"
#undef malloc
#undef free
void libcdsb_stack_init(stack_t* x) {
memset(x, 0, sizeof(*x));
}
void libcdsb_stack_push(stack_t* x, void* value) {
stack_t* n;
if (x->value) {
if (!(n = malloc(sizeof(*n))))
abort();
n->prev = x->prev;
n->value = x->value;
x->prev = n;
}
x->value = value;
}
void libcdsb_stack_push_many(stack_t* x, size_t c, ...) {
va_list args;
stack_t* n;
va_start(args, c);
if (c) {
if (!x->value) {
x->value = va_arg(args, void*);
--c;
}
while (c--) {
if (!(n = malloc(sizeof(*n))))
abort();
n->prev = x->prev;
n->value = x->value;
x->prev = n;
x->value = va_arg(args, void*);
}
}
va_end(args);
}
void* libcdsb_stack_pop(stack_t* x) {
stack_t* n;
void* v;
v = x->value;
if (x->prev) {
n = x->prev;
x->prev = n->prev;
x->value = n->value;
free(n);
} else x->value = 0;
return v;
}
void libcdsb_stack_reverse(stack_t* x) {
stack_t z, *iter, *n, copy;
if (x->prev) {
z.prev = 0;
z.value = x->value;
iter = x->prev;
while (iter->prev) {
n = iter;
iter = n->prev;
copy.prev = z.prev;
copy.value = z.value;
z.prev = n;
z.value = n->value;
n->prev = copy.prev;
n->value = copy.value;
}
copy.prev = z.prev;
copy.value = z.value;
x->prev = iter;
x->value = iter->value;
iter->prev = copy.prev;
iter->value = copy.value;
}
}
void libcdsb_stack_flush(stack_t* x) {
stack_t* c;
while (x->prev) {
c = x->prev;
x->prev = c->prev;
free(c);
}
x->value = 0;
}