Module Timed_compatSource

Timed references for Stdlib.ref. This module redefines the all the functions used to update references, and enables the restoration of saved reference states.

Note that this module allocates one blocks of memory at initialization for its internal state. It occupies a total of four words.

Sourceval (:=) : 'a ref -> 'a -> unit

r := v sets the value of the reference r to v. This operation has a very small overhead compared to Stdlib.((:=)) if no time has been via Time.save. Nonetheless, it is always constant time, and allocation is only necessary if the current “time” is accessible (or not reclaimed by the garbage-collector). When that is the case, three blocks of memory are allocated, for a total of eight words.

Sourceval incr : int ref -> unit

incr r is equivalent to r := !r + 1.

Sourceval decr : int ref -> unit

decr r is equivalent to r := !r - 1.

Sourcemodule Time : sig ... end

The Time module provides an abstract representation of time, used to set a point from which (monitored) updates to references are recorded to allow undoing/redoing the corresponding changes.

Sourceval pure_apply : ('a -> 'b) -> 'a -> 'b

pure_apply f v computes the result of f v, but reverts the (monitored) updates made to references in the process before returning the value.

Sourceval pure_test : ('a -> bool) -> 'a -> bool

pure_test p v applies the predicate p to v (i.e., compute p v) and returns the result, reverting (monitored) updates made to reference if the result is false. Updates are preserved if the result is true.