push - Append an element.
pop - Remove and return the last element.
clear - Remove all elements.
shift - Remove and return the first element.
first_element - Return the first element. We can't use first because
it's taken by the dplyr package and is not an S3 method.
last_element - Return the last element. We can't use last because
it's taken by the dplyr package and is not an S3 method.
size - Return the number of elements.
as.Stack - Creates a new Stack from (typically, vector) s.
as.StackList - Creates a new StackList from (typically, list) s.
Stack() - Creates and keeps a stack of items of the same type, implemented as an R vector.
The type is determined by the first push operation.
StackList() - Creates and keeps a list of items of the same type, implemented as an R list.
The type is determined by the first push operation.
push(x, value)pop(x)
clear(x)
shift(x)
first_element(x)
last_element(x)
size(x)
as.Stack(s)
as.StackList(s)
Stack()
StackList()
A Stack or StackList object.
Value to append.
A structure to be converted to a Stack or StackList.