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.