Module Stdlib.StackSource

Last-in first-out stacks.

This module implements stacks (LIFOs), with in-place modification.

Unsynchronized accesses

Unsynchronized accesses to a stack may lead to an invalid queue state. Thus, concurrent accesses to stacks must be synchronized (for instance with a Mutex.t).

Sourcetype !'a t

The type of stacks containing elements of type 'a.

Sourceexception Empty

Raised when Stack.pop or Stack.top is applied to an empty stack.

Sourceval create : unit -> 'a t

Return a new stack, initially empty.

Sourceval push : 'a -> 'a t -> unit

push x s adds the element x at the top of stack s.

Sourceval pop : 'a t -> 'a

pop s removes and returns the topmost element in stack s, or raises Empty if the stack is empty.

Sourceval pop_opt : 'a t -> 'a option

pop_opt s removes and returns the topmost element in stack s, or returns None if the stack is empty.

  • since 4.08
Sourceval drop : 'a t -> unit

drop s removes the topmost element in stack s, or raises Empty if the stack is empty.

  • since 5.1
Sourceval top : 'a t -> 'a

top s returns the topmost element in stack s, or raises Empty if the stack is empty.

Sourceval top_opt : 'a t -> 'a option

top_opt s returns the topmost element in stack s, or None if the stack is empty.

  • since 4.08
Sourceval clear : 'a t -> unit

Discard all elements from a stack.

Sourceval copy : 'a t -> 'a t

Return a copy of the given stack.

Sourceval is_empty : 'a t -> bool

Return true if the given stack is empty, false otherwise.

Sourceval length : 'a t -> int

Return the number of elements in a stack. Time complexity O(1)

Sourceval iter : ('a -> unit) -> 'a t -> unit

iter f s applies f in turn to all elements of s, from the element at the top of the stack to the element at the bottom of the stack. The stack itself is unchanged.

Sourceval fold : ('acc -> 'a -> 'acc) -> 'acc -> 'a t -> 'acc

fold f accu s is (f (... (f (f accu x1) x2) ...) xn) where x1 is the top of the stack, x2 the second element, and xn the bottom element. The stack is unchanged.

  • since 4.03

Stacks and Sequences

Sourceval to_seq : 'a t -> 'a Seq.t

Iterate on the stack, top to bottom. It is safe to modify the stack during iteration.

  • since 4.07
Sourceval add_seq : 'a t -> 'a Seq.t -> unit

Add the elements from the sequence on the top of the stack.

  • since 4.07
Sourceval of_seq : 'a Seq.t -> 'a t

Create a stack from the sequence.

  • since 4.07