A stack implemented with a list. See Stack_intf for documentation.
Checks whether the provided element is there, using polymorphic compare if equal
is not provided
fold t ~init ~f returns f (... f (f (f init e1) e2) e3 ...) en, where e1..en
are the elements of t
Returns true if and only if there exists an element for which the provided
function evaluates to true. This is a short-circuiting operation.
Returns true if and only if the provided function evaluates to true for all
elements. This is a short-circuiting operation.
Returns the number of elements for which the provided function evaluates to true.
Returns as an option the first element for which f evaluates to true.
Returns the first evaluation of f that returns Some, and returns None if there
is no such element.
Returns a minimum (resp maximum) element from the collection using the provided
cmp function, or None if the collection is empty. In case of a tie, the first
element encountered while traversing the collection is returned. The implementation
uses fold so it has the same complexity as fold.
of_list l returns a stack whose top is the first element of l and bottom is the
last element of l.
create () returns an empty stack.
singleton a creates a new stack containing only a.
push t a adds a to the top of stack t.
pop t removes and returns the top element of t as Some a, or returns None if
t is empty.
top t returns Some a, where a is the top of t, unless is_empty t, in which
case top returns None.
clear t discards all elements from t.
until_empty t f repeatedly pops an element a off of t and runs f a, until
t becomes empty. It is fine if f adds more elements to t, in which case the
most-recently-added element will be processed next.