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

The equality predicate used to compare keys.

val hash : 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 Map.OrderedType with type t := T.t
val compare : T.t -> 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 : out_channel -> T.t -> unit
val print : Format.formatter -> T.t -> unit
module Set : Identifiable.Set with module T := T
module Map : Identifiable.Map with module T := T
module Tbl : Identifiable.Tbl with module T := T
val to_string : t -> string
val format : Format.formatter -> t -> unit
val fail : 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 -> sequence

Create a new sequence for generating static labels.

val reset : sequence -> unit

Reset a sequence to start from label 0.

val get_and_incr : sequence -> t

Generate and consume the next label from the sequence.

val of_int_unsafe : int -> t

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