added a char stack implementation for later use

[smdp.git] / cstack.c

diff --git a/cstack.c b/cstack.c
new file mode 100644 (file)
index 0000000..6474436
--- /dev/null
+++ b/cstack.c
@@ -0,0 +1,44 @@
+#include <stdlib.h> // malloc, realloc
+
+#include "include/cstack.h"
+
+cstack_t *cstack_init() {
+    cstack_t *stack = malloc(sizeof(cstack_t));
+    stack->content = (void*)0;
+    stack->alloc = stack->size = 0;
+    stack->head = -1;
+    stack->push = cstack_push;
+    stack->pop = cstack_pop;
+    stack->top = cstack_top;
+    stack->empty = cstack_empty;
+    stack->delete = cstack_delete;
+    return stack;
+}
+
+void cstack_push(cstack_t *self, char c) {
+    if(self->size + sizeof(c) > self->alloc) {
+        self->alloc += (sizeof(char));
+        self->content = realloc(self->content, self->alloc);
+    }
+    self->content[++self->head] = c;
+    self->size += (sizeof(char));
+}
+
+char cstack_pop(cstack_t *self) {
+    self->size -= (sizeof(char));
+    return self->content[self->head--];
+}
+
+char cstack_top(cstack_t *self) {
+    return self->content[self->head];
+}
+
+int cstack_empty(cstack_t *self)  {
+   return self->head == -1;
+}
+
+void cstack_delete(cstack_t *self) {
+    free(self->content);
+    free(self);
+}
+