package ocaml-base-compiler

  1. Overview
  2. Docs
Official release 5.1.1

Install 

dune-project
 Dependency

ocaml.org Edit opam file Versions (70)

Authors

  1. Xavier Leroy

Maintainers

  1. David Allsopp
  2. F
    Florian Angeletti <florian.angeletti@inria.fr>

Sources

5.1.1.tar.gz
sha256=57f7b382b3d71198413ede405d95ef3506f1cdc480cda1dca1e26b37cb090e17

doc/compiler-libs.optcomp/Backend_var/index.html

Module Backend_var

Variables used in the backend, optionally equipped with "provenance" information, used for the emission of debugging information.

include module type of struct include Ident end
type t = Ident.t
include Identifiable.S with type t := t
module T = Ident.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 output : out_channel -> T.t -> unit
val print : Format.formatter -> T.t -> unit
module Set = Ident.Set
module Map = Ident.Map
module Tbl = Ident.Tbl
val print_with_scope : Format.formatter -> t -> unit

Same as print except that it will also add a "n" suffix if the scope of the argument is n.

val create_scoped : scope:int -> string -> t
val create_local : string -> t
val create_persistent : string -> t
val create_predef : string -> t
val rename : t -> t

Creates an identifier with the same name as the input, a fresh stamp, and no scope.

  • raises [Fatal_error]

    if called on a persistent / predef ident.

val name : t -> string
val unique_name : t -> string
val unique_toplevel_name : t -> string
val persistent : t -> bool
val same : t -> t -> bool

Compare identifiers by binding location. Two identifiers are the same either if they are both non-persistent and have been created by the same call to create_*, or if they are both persistent and have the same name.

val compare : t -> t -> int
val global : t -> bool
val is_predef : t -> bool
val scope : t -> int
val lowest_scope : int
val highest_scope : int
val reinit : unit -> unit
type 'a tbl = 'a Ident.tbl

'a tbl represents association tables from identifiers to values of type 'a.

'a tbl plays the role of map, but bindings can be looked up from either the full Ident using find_same, or just its user-visible name using find_name. In general the two lookups may not return the same result, as an identifier may have been shadowed in the environment by a distinct identifier with the same name.

find_all returns the bindings for all idents of a given name, most recently introduced first.

In other words, 'a tbl corresponds to (Ident.t * 'a) list Map.Make(String) and the implementation is very close to that representation.

Note in particular that searching among idents of the same name takes linear time, and that add simply extends the list without checking for duplicates. So it is not a good idea to implement union by repeated add calls, which may result in many duplicated identifiers and poor find_same performance. It is even possible to build overly large same-name lists such that non-recursive functions like find_all or fold_all blow the stack.

You should probably use Map.Make(Ident) instead, unless you really need to query bindings by user-visible name, not just by unique identifiers.

val empty : 'a tbl
val add : t -> 'a -> 'a tbl -> 'a tbl
val find_same : t -> 'a tbl -> 'a
val find_name : string -> 'a tbl -> t * 'a
val find_all : string -> 'a tbl -> (t * 'a) list
val find_all_seq : string -> 'a tbl -> (t * 'a) Seq.t
val fold_name : (t -> 'a -> 'b -> 'b) -> 'a tbl -> 'b -> 'b
val fold_all : (t -> 'a -> 'b -> 'b) -> 'a tbl -> 'b -> 'b
val iter : (t -> 'a -> unit) -> 'a tbl -> unit
val remove : t -> 'a tbl -> 'a tbl
val make_key_generator : unit -> t -> t
type backend_var = t
module Provenance : sig ... end
module With_provenance : sig ... end