#if !defined( CSTACK_H )
#define CSTACK_H
+/*
+ * A implementation of a char stack in heap memory.
+ *
+ * struct: cstack_t which defines char stack type in heap memory
+ *
+ * function: cstack_init to intialize struct of type cstack_t
+ * function: cstack_t->push to add one char on top if the stack
+ * function: cstack_t->pop to remove the top char from the stack
+ * function: cstack_t->top to test if the top char is a given char
+ * function: cstack_t->empty to test if the stack is empty
+ * function: cstack_t->delete to free the allocated memory
+ *
+ * Example:
+ * cstack_t *p = cstack_init();
+ * (p->push)(p, 'X');
+ * printf("%c\n", (p->pop)(p));
+ * (p->delete)(p);
+ *
+ */
+
typedef struct _cstack_t {
char *content;
size_t alloc;
int head;
void (*push)(struct _cstack_t *self, char c);
char (*pop)(struct _cstack_t *self);
- char (*top)(struct _cstack_t *self);
+ int (*top)(struct _cstack_t *self, char c);
int (*empty)(struct _cstack_t *self);
void (*delete)(struct _cstack_t *self);
} cstack_t;
cstack_t *cstack_init();
void cstack_push(cstack_t *self, char c);
char cstack_pop(cstack_t *self);
-char cstack_top(cstack_t *self);
+int cstack_top(cstack_t *self, char c);
int cstack_empty(cstack_t *self);
void cstack_delete(cstack_t *self);