19 do_push (List *stack, void *elem, int isstring)  in do_push()  argument
28     addnode(stack, p);  in do_push()
34 push (List *stack, void *elem)  in push()  argument
36     do_push (stack, elem, 0);  in push()
42 push_string (List *stack, char *elem)  in push_string()  argument
44     do_push (stack, elem, 1);  in push_string()
50 do_pop (List *stack, int isstring)  in do_pop()  argument
54     if (isempty (stack)) return NULL;  in do_pop()
58 	elem = stack->list->prev->key;  in do_pop()
59 	stack->list->prev->key = NULL;  in do_pop()
63 	elem = stack->list->prev->data;  in do_pop()
64 	stack->list->prev->data = NULL;  in do_pop()
67     delnode (stack->list->prev);  in do_pop()
74 pop (List *stack)  in pop()  argument
76     return do_pop (stack, 0);  in pop()
82 pop_string (List *stack)  in pop_string()  argument
84     return do_pop (stack, 1);  in pop_string()
90 do_unshift (List *stack, void *elem, int isstring)  in do_unshift()  argument
99     addnode_at_front(stack, p);  in do_unshift()
105 unshift (List *stack, void *elem)  in unshift()  argument
107     do_unshift (stack, elem, 0);  in unshift()
113 unshift_string (List *stack, char *elem)  in unshift_string()  argument
115     do_unshift (stack, elem, 1);  in unshift_string()
121 do_shift (List *stack, int isstring)  in do_shift()  argument
125     if (isempty (stack)) return NULL;  in do_shift()
129 	elem = stack->list->next->key;  in do_shift()
130 	stack->list->next->key = NULL;  in do_shift()
134 	elem = stack->list->next->data;  in do_shift()
135 	stack->list->next->data = NULL;  in do_shift()
137     delnode (stack->list->next);  in do_shift()
144 shift (List *stack)  in shift()  argument
146     return do_shift (stack, 0);  in shift()
152 shift_string (List *stack)  in shift_string()  argument
154     return do_shift (stack, 1);  in shift_string()
160 isempty (List *stack)  in isempty()  argument
162     if (stack->list == stack->list->next)  in isempty()