LispKit Stack
Library (lispkit stack) provides an implementation for mutable stacks, i.e. mutable LIFO buffers.
(make-stack) [procedure]
Returns a new empty stack.
(stack x ...) [procedure]
Returns a new stack with x on its top position followed by the remaining parameters.
(stack-top (stack 1 2 3)) ⟹ 1
(stack? obj) [procedure]
Returns #t if obj is a stack; otherwise #f is returned.
(stack-empty? s) [procedure]
Returns #t if stack s is empty.
(stack-size s) [procedure]
Returns the size of stack s, i.e. the number of elements buffered in s.
(stack=? s1 s2) [procedure]
Returns #t if stack s1 has the exact same elements in the same order like stack s2; otherwise, #f is returned.
(stack-push! s x) [procedure]
Pushes element x onto stack s.
(stack-top s) [procedure]
Returns the top element of stack s. If the stack is empty, an error is raised.
(stack-pop! s) [procedure]
Removes the top element from stack s and returns its value.
(define s (make-stack))
(stack-push! s 1)
(stack-push! s 2)
(stack-pop! s) ⟹ 2
(stack-size s) ⟹ 1
(stack-clear! s) [procedure]
Removes all elements from stack s.
(stack-copy s) [procedure]
Returns a copy of stack s.
(stack->list s) [procedure]
Returns a list consisting of all elements on stack s in the order they appear, i.e. starting with the top element.
(stack->list (stack 1 2 3))
(list->stack l) [procedure]
Returns a new stack consisting of the elements of list l. The first element in l will become the top element of the stack that is returned.
(list->stack! s l) [procedure]
Pushes the elements of list l onto stack s in reverse order.
(define s (list->stack '(3 2 1)))
(list->stack! s '(6 5 4))
(stack->list s) ⟹ (6 5 4 3 2 1)