Module Lazy

structure Lazy = struct ... end 

Deferred computations.

A value of type 'a Lazy.t is a deferred computation (also called a suspension) that computes a result of type 'a. The expression lazy (expr) returns a suspension that computes expr. *

exception Undefined

val force : 'a t -> 'a

Lazy.force x computes the suspension x and returns its result. If the suspension was already computed, Lazy.force x returns the same value again. If it raised an exception, the same exception is raised again. Raise Undefined if the evaluation of the suspension requires its own result.