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Module Static_label

Static exception labels used in Lambda intermediate representation.

Static exceptions provide a mechanism for local control flow transfer within functions. Unlike regular exceptions, the target handler is statically known and control flow cannot escape function boundaries.

type t
include Identifiable.S with type t := Static_label.t
module T : Identifiable.Thing with type t = Static_label.t
include Identifiable.Thing with type t := Static_label.T.t
include Stdlib.Hashtbl.HashedType with type t := Static_label.T.t
val equal : Static_label.T.t -> Static_label.T.t -> bool

The equality predicate used to compare keys.

val hash : Static_label.T.t -> int

A hashing function on keys. It must be such that if two keys are equal according to equal, then they have identical hash values as computed by hash. Examples: suitable (equal, hash) pairs for arbitrary key types include

  • ((=), hash) for comparing objects by structure (provided objects do not contain floats)
  • ((fun x y -> compare x y = 0), hash) for comparing objects by structure and handling Stdlib.nan correctly
  • ((==), hash) for comparing objects by physical equality (e.g. for mutable or cyclic objects).
include Stdlib.Map.OrderedType with type t := Static_label.T.t
val compare : Static_label.T.t -> Static_label.T.t -> int

A total ordering function over the keys. This is a two-argument function f such that f e1 e2 is zero if the keys e1 and e2 are equal, f e1 e2 is strictly negative if e1 is smaller than e2, and f e1 e2 is strictly positive if e1 is greater than e2. Example: a suitable ordering function is the generic structural comparison function Stdlib.compare.

val output : Stdlib.out_channel -> Static_label.T.t -> unit
module Set : Identifiable.Set with module T := Static_label.T
module Map : Identifiable.Map with module T := Static_label.T
module Tbl : Identifiable.Tbl with module T := Static_label.T
val to_string : Static_label.t -> string
val format : Stdlib.Format.formatter -> Static_label.t -> unit
val fail : Static_label.t

Special static label used for anticipated static raises (guards). This corresponds to the legacy hardcoded value 0.

type sequence

A sequence for generating fresh static labels.

val make_sequence : unit -> Static_label.sequence

Create a new sequence for generating static labels.

val reset : Static_label.sequence -> unit

Reset a sequence to start from label 0.

Generate and consume the next label from the sequence.

val of_int_unsafe : int -> Static_label.t

Convert an integer to a static label. This function should only be used when interfacing with legacy code that provides raw integers.