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Module Var.SetFd


module SetFd: BASICFD 
 with
     type domain = SetDomain.t
     and type elt = SetDomain.S.t
     and type attr = SetAttr.t
     and type event = SetAttr.event
Concrete integer set variable module.
type t
Type of finite domain variable.
type attr
Type of attributes.
type domain
Type of domains.
type elt
Type of elements of domains.
type event
Type of domain reduction events.

Creation


val create : ?name:string -> domain -> t
create ?name d returns a new variable with domain d. If provided, name will be used by the pretty printer.
val interval : ?name:string -> elt -> elt -> t
interval ?name inf sup returns a new variable with domain [inf..sup]. If provided, name will be used by the pretty printer.
val array : ?name:string ->
       int -> elt -> elt -> t array
array n inf sup returns an array of n new variables with domain [inf..sup]. If provided, name (suffixed with the index of the element) will be used by the pretty printer.
val elt : elt -> t
int n returns a new variable instantiated to integer value n.

Access


val is_var : t -> bool
is_var v returns true if v is not instantiated and false otherwise.
val is_bound : t -> bool
is_bound v returns true if v is instantiated and false otherwise.
val value : t -> (attr, elt) Var.concrete
value v returns Val n if v is instantiated to n, Unk a otherwise where a is the attribute of v. Should always be used in a matching: match value v with Val n -> ... | Unk a -> ....
val min : t -> elt
min v returns the lower bound of v.
val max : t -> elt
max v returns the upper bound of v.
val min_max : t -> elt * elt
min_max v returns both the lower and upper bounds of v.
val elt_value : t -> elt
int_value v returns the value of v if it is instantiated and raises a Failure exception otherwise.
val int_value : t -> elt
val size : t -> int
size v returns the number of integer values in the domain of v (1 if v is instantiated).
val member : t -> elt -> bool
member v n returns true if n belongs to the domain of v and false otherwise.
val id : t -> int
id v returns a unique integer identifying the attribute associated with v. Must be called only on non ground variable, raise Failure otherwise.
val name : t -> string
name v returns the name of variable v (the empty string if it was not provided while created). Must be called only on non ground variable, raise Failure otherwise.
val compare : t -> t -> int
Compares two variables. Values (bound variables) are smaller than unknowns (unbound variables). Unknowns are sorted according to their attribute id.
val equal : t -> t -> bool
Tests if two variables are equal with respect to compare.
val fprint : Pervasives.out_channel -> t -> unit
fprint chan v prints variable v on channel chan.
val fprint_array : Pervasives.out_channel -> t array -> unit
fprint_array chan vs prints array of variables vs on channel chan.

Refinement


val unify : t -> elt -> unit
unify v n instantiates variable v with integer value n. Raises Stak.Fail in case of failure. unify may be called either on unbound variables or on instantiated variables.
val refine : t -> domain -> unit
refine v d reduces the domain of v with domain d. d must be included in the domain of v, otherwise the behaviour is unspecified (corrupted system or exception raised).
val refine_low : t -> elt -> unit
refine_low v inf reduces the domain of v by cutting all values strictly less than inf.
val refine_up : t -> elt -> unit
refine_up v sup reduces the domain of v by cutting all values strictly greater than sup.
val refine_low_up : t -> elt -> elt -> unit
refine_low_up v inf sup reduces the domain of v by cutting all values strictly less than inf and greater than sup. Robust even if v is already bound (checks that inf <= v <= sup, otherwise fails).

Events and suspending


val on_refine : event
Event occuring when a variable is changed, i.e. its domain modified.
val on_subst : event
Event occuring when a variable is instantiated.
val on_min : event
val on_max : event
Event occuring when the lower (resp. upper) bound of a variable decreases.
val delay : event list -> t -> ?waking_id:int -> Cstr.t -> unit
delay event_list v ~waking_id:id c suspends constraint c on all the events in event_list occurring on v. An optional integer id may be associated to the wakening: it must be unique and range from 0 to nb_wakings-1, nb_wakings being the argument of Cstr.create specifying the number of calls to delay with distinct waking_id arguments. These integers are arguments to the "update" function of constraints and aim at discriminating waking events to fire the appropriate propagation rule. waking_id default value is 0. This function has no effect on instantiated variables (as no event could occur on a ground variable).