Module Bi_io

Input and output functions for the Biniou serialization format

Node tags

type node_tag = int
val bool_tag : node_tag

Tag indicating a bool node.

val int8_tag : node_tag

Tag indicating a bool node.

Tag indicating an int8 node.

val int16_tag : node_tag

Tag indicating an int8 node.

Tag indicating an int16 node.

val int32_tag : node_tag

Tag indicating an int16 node.

Tag indicating an int32 node.

val int64_tag : node_tag

Tag indicating an int32 node.

Tag indicating an int64 node.

val float32_tag : node_tag

Tag indicating an int64 node.

Tag indicating a float32 node.

val float64_tag : node_tag

Tag indicating a float32 node.

Tag indicating a float64 node.

val uvint_tag : node_tag

Tag indicating a float64 node.

Tag indicating a uvint node.

val svint_tag : node_tag

Tag indicating a uvint node.

Tag indicating an svint node.

val string_tag : node_tag

Tag indicating an svint node.

Tag indicating a string node.

val array_tag : node_tag

Tag indicating a string node.

Tag indicating an array node.

val tuple_tag : node_tag

Tag indicating an array node.

Tag indicating a tuple node.

val record_tag : node_tag

Tag indicating a tuple node.

Tag indicating a record node.

val num_variant_tag : node_tag

Tag indicating a record node.

Tag indicating a num_variant node.

val variant_tag : node_tag

Tag indicating a num_variant node.

Tag indicating a variant node.

val unit_tag : node_tag

Tag indicating a variant node.

Tag indicating a unit node.

val table_tag : node_tag

Tag indicating a unit node.

Tag indicating a table node.

val shared_tag : node_tag

Tag indicating a table node.

Tag indicating a shared node.

val write_tag : Bi_outbuf.t -> node_tag -> unit

Write one-byte tag to a buffer.

val read_tag : Bi_inbuf.t -> node_tag

Read one-byte tag from a buffer.

Tags of variants and record fields

type hash = int

31-bit hash

val hash_name : string -> hash

Hash function used to compute field name tags and variant tags from their full name.

val write_hashtag : Bi_outbuf.t -> hash -> bool -> unit

write_hashtag ob h has_arg writes variant tag h to buffer ob. has_arg indicates whether the variant has an argument. This function can be used for record field names as well, in which case has_arg may only be true.

val string_of_hashtag : hash -> bool -> string

Same as write_hashtag but writes to a string.

val read_hashtag : Bi_inbuf.t -> (Bi_inbuf.t -> hash -> bool -> 'a) -> 'a

read_hashtag ib f reads a variant tag as hash h and flag has_arg and returns f h has_arg.

val read_field_hashtag : Bi_inbuf.t -> hash

read_field_hashtag ib reads a field tag and returns the 31-bit hash.

val make_unhash : string list -> hash -> string option

Compute the hash of each string of the input list and return a function that converts a hash back to the original string. Lookups do not allocate memory blocks.

  • raises Failure

    if the input list contains two different strings with the same hash.

type int7 = int

7-bit int used to represent a num_variant tag.

val write_numtag : Bi_outbuf.t -> int7 -> bool -> unit

write_numtag ob i has_arg writes the tag of a num_variant. The tag name is represented by i which must be within [0, 127] and the flag has_arg which indicates the presence of an argument.

val read_numtag : Bi_inbuf.t -> (Bi_inbuf.t -> int7 -> bool -> 'a) -> 'a

read_numtag ib f reads a num_variant tag and processes the tag name i and flag has_arg using f.

Atom writers

The write_untagged_ functions write an untagged value (VAL) to an output buffer while the other write_ functions write a tagged value (TAGVAL).

val write_untagged_unit : Bi_outbuf.t -> unit -> unit
val write_untagged_bool : Bi_outbuf.t -> bool -> unit
val write_untagged_char : Bi_outbuf.t -> char -> unit
val write_untagged_int8 : Bi_outbuf.t -> int -> unit
val write_untagged_int16 : Bi_outbuf.t -> int -> unit
val write_untagged_int32 : Bi_outbuf.t -> int32 -> unit
val write_untagged_int64 : Bi_outbuf.t -> int64 -> unit
val write_untagged_float32 : Bi_outbuf.t -> float -> unit
val write_untagged_float64 : Bi_outbuf.t -> float -> unit
val write_untagged_string : Bi_outbuf.t -> string -> unit
val write_untagged_uvint : Bi_outbuf.t -> int -> unit
val write_untagged_svint : Bi_outbuf.t -> int -> unit
val write_unit : Bi_outbuf.t -> unit -> unit
val write_bool : Bi_outbuf.t -> bool -> unit
val write_char : Bi_outbuf.t -> char -> unit
val write_int8 : Bi_outbuf.t -> int -> unit
val write_int16 : Bi_outbuf.t -> int -> unit
val write_int32 : Bi_outbuf.t -> int32 -> unit
val write_int64 : Bi_outbuf.t -> int64 -> unit
val write_float32 : Bi_outbuf.t -> float -> unit
val write_float64 : Bi_outbuf.t -> float -> unit
val write_string : Bi_outbuf.t -> string -> unit
val write_uvint : Bi_outbuf.t -> int -> unit
val write_svint : Bi_outbuf.t -> int -> unit

Atom readers

The read_untagged_ functions read an untagged value (VAL) from an input buffer.

val read_untagged_unit : Bi_inbuf.t -> unit
val read_untagged_bool : Bi_inbuf.t -> bool
val read_untagged_char : Bi_inbuf.t -> char
val read_untagged_int8 : Bi_inbuf.t -> int
val read_untagged_int16 : Bi_inbuf.t -> int
val read_untagged_int32 : Bi_inbuf.t -> int32
val read_untagged_int64 : Bi_inbuf.t -> int64
val read_untagged_float32 : Bi_inbuf.t -> float
val read_untagged_float64 : Bi_inbuf.t -> float
val read_untagged_string : Bi_inbuf.t -> string
val read_untagged_uvint : Bi_inbuf.t -> int
val read_untagged_svint : Bi_inbuf.t -> int
val skip : Bi_inbuf.t -> unit

Read and discard a value. Useful for skipping unknown record fields.

Generic tree

type tree = [
| `Unit
| `Bool of bool
| `Int8 of char
| `Int16 of int
| `Int32 of Int32.t
| `Int64 of Int64.t
| `Float32 of float
| `Float64 of float
| `Uvint of int
| `Svint of int
| `String of string
| `Array of (node_tag * tree array) option
| `Tuple of tree array
| `Record of (string option * hash * tree) array
| `Num_variant of int * tree option
| `Variant of string option * hash * tree option
| `Table of ((string option * hash * node_tag) array * tree array array) option
| `Shared of tree
]

Tree representing serialized data, useful for testing and for untyped transformations.

val write_tree : Bi_outbuf.t -> tree -> unit

Serialization of a tree to a buffer.

val string_of_tree : tree -> string

Serialization of a tree into a string.

val read_tree : ?unhash:(hash -> string option) -> Bi_inbuf.t -> tree

Deserialization of a tree from a buffer.

val tree_of_string : ?unhash:(hash -> string option) -> string -> tree

Deserialization of a tree from a string.

val tag_of_tree : tree -> node_tag

Returns the node tag of the given tree.

val view_of_tree : tree -> string
val view : ?unhash:(hash -> string option) -> string -> string

Prints a human-readable representation of the data into a string.

val print_view_of_tree : tree -> unit
val print_view : ?unhash:(hash -> string option) -> string -> unit

Prints a human-readable representation of the data to stdout.

val output_view_of_tree : out_channel -> tree -> unit
val output_view : ?unhash:(hash -> string option) -> out_channel -> string -> unit

Prints a human-readable representation of the data to an out_channel.

val safety_test : unit -> unit

Check that certain low-level hacks work as expected