Module Bitstring_persistent

module Bitstring_persistent: sig .. end

type patt = Camlp4.PreCast.Syntax.Ast.patt 

type expr = Camlp4.PreCast.Syntax.Ast.expr 

type loc_t = Camlp4.PreCast.Syntax.Ast.Loc.t 

Just short names for the camlp4 types.

type 'a field 

A field in a persistent pattern or persistent constructor.

type pattern = patt field list 

A persistent pattern (used in bitmatch operator), is just a list of pattern fields.

type constructor = expr field list 

A persistent constructor (used in BITSTRING operator), is just a list of constructor fields.

type named = string * alt 

type alt = 

A named pattern or constructor.

The name is used when binding a pattern from a file, but is otherwise ignored.

val string_of_pattern : pattern -> string

val string_of_constructor : constructor -> string

val string_of_pattern_field : patt field -> string

val string_of_constructor_field : expr field -> string

Convert patterns, constructors or individual fields into printable strings for debugging purposes.

The strings look similar to the syntax used by bitmatch, but some things cannot be printed fully, eg. length expressions.

val named_to_channel : Pervasives.out_channel -> named -> unit

Save a pattern/constructor to an output channel.

val named_to_string : named -> string

Serialize a pattern/constructor to a string.

val named_to_buffer : string -> int -> int -> named -> int

Serialize a pattern/constructor to part of a string, return the length.

val named_from_channel : Pervasives.in_channel -> named

Load a pattern/constructor from an output channel.

Note: This is not type safe. The pattern/constructor must have been written out under the same version of OCaml and the same version of bitstring.

val named_from_string : string -> int -> named

Load a pattern/constructor from a string at offset within the string.

Note: This is not type safe. The pattern/constructor must have been written out under the same version of OCaml and the same version of bitstring.

val create_pattern_field : loc_t ->
       patt field

Create a pattern field.

The pattern is unbound, the type is set to int, bit length to 32, endianness to BigEndian, signedness to unsigned (false), source code location to the _loc parameter, and no offset expression.

To create a complete field you need to call the set_* functions. For example, to create { len : 8 : int } you would do:

    let field = create_pattern_field _loc in
    let field = set_lident_patt field "len" in
    let field = set_length_int field 8 in

val set_lident_patt : patt field ->
       string -> patt field

Sets the pattern to the pattern binding an identifier given in the string.

The effect is that the field { len : 8 : int } could be created by calling set_lident_patt field "len".

val set_int_patt : patt field ->
       int -> patt field

Sets the pattern field to the pattern which matches an integer.

The effect is that the field { 2 : 8 : int } could be created by calling set_int_patt field 2.

val set_string_patt : patt field ->
       string -> patt field

Sets the pattern field to the pattern which matches a string.

The effect is that the field { "MAGIC" : 8*5 : string } could be created by calling set_int_patt field "MAGIC".

val set_unbound_patt : patt field ->
       patt field

Sets the pattern field to the unbound pattern (usually written _).

The effect is that the field { _ : 8 : int } could be created by calling set_unbound_patt field.

val set_patt : patt field ->
       patt ->
       patt field

Sets the pattern field to an arbitrary OCaml pattern match.

val set_length_int : 'a field -> int -> 'a field

Sets the length in bits of a field to a constant integer.

The effect is that the field { len : 8 : string } could be created by calling set_length field 8.

val set_length : 'a field ->
       expr -> 'a field

Sets the length in bits of a field to an OCaml expression.

The effect is that the field { len : 2*i : string } could be created by calling set_length field <:expr< 2*i >>.

val set_endian : 'a field ->
       Bitstring.endian -> 'a field

Sets the endianness of a field to the constant endianness.

The effect is that the field { _ : 16 : bigendian } could be created by calling set_endian field Bitstring.BigEndian.

val set_endian_expr : 'a field ->
       expr -> 'a field

Sets the endianness of a field to an endianness expression.

The effect is that the field { _ : 16 : endian(e) } could be created by calling set_endian_expr field e.

val set_signed : 'a field -> bool -> 'a field

Sets the signedness of a field to a constant signedness.

The effect is that the field { _ : 16 : signed } could be created by calling set_signed field true.

val set_type_int : 'a field -> 'a field

Sets the type of a field to int.

The effect is that the field { _ : 16 : int } could be created by calling set_type_int field.

val set_type_string : 'a field -> 'a field

Sets the type of a field to string.

The effect is that the field { str : 16 : string } could be created by calling set_type_string field.

val set_type_bitstring : 'a field -> 'a field

Sets the type of a field to bitstring.

The effect is that the field { _ : 768 : bitstring } could be created by calling set_type_bitstring field.

val set_location : 'a field ->
       loc_t -> 'a field

Sets the source code location of a field. This is used when pa_bitstring displays error messages.

val set_offset_int : 'a field -> int -> 'a field

Set the offset expression for a field to the given number.

The effect is that the field { _ : 8 : offset(160) } could be created by calling set_offset_int field 160.

val set_offset : 'a field ->
       expr -> 'a field

Set the offset expression for a field to the given expression.

The effect is that the field { _ : 8 : offset(160) } could be created by calling set_offset_int field <:expr< 160 >>.

val set_no_offset : 'a field -> 'a field

Remove the offset expression from a field. The field will follow the previous field, or if it is the first field will be at offset zero.

val set_check : 'a field ->
       expr -> 'a field

Set the check expression for a field to the given expression.

val set_no_check : 'a field -> 'a field

Remove the check expression from a field.

val set_bind : 'a field ->
       expr -> 'a field

Set the bind-expression for a field to the given expression.

val set_no_bind : 'a field -> 'a field

Remove the bind-expression from a field.

val set_save_offset_to : 'a field ->
       patt -> 'a field

Set the save_offset_to pattern for a field to the given pattern.

val set_save_offset_to_lident : 'a field -> string -> 'a field

Set the save_offset_to pattern for a field to identifier.

val set_no_save_offset_to : 'a field -> 'a field

Remove the save_offset_to from a field.

val create_constructor_field : loc_t ->
       expr field

Create a constructor field.

The defaults are the same as for Bitstring_persistent.create_pattern_field except that the expression is initialized to 0.

val set_lident_expr : expr field ->
       string -> expr field

Sets the expression in a constructor field to an expression which uses the identifier.

The effect is that the field { len : 8 : int } could be created by calling set_lident_expr field "len".

val set_int_expr : expr field ->
       int -> expr field

Sets the expression to the value of the integer.

The effect is that the field { 2 : 8 : int } could be created by calling set_int_expr field 2.

val set_string_expr : expr field ->
       string -> expr field

Sets the expression to the value of the string.

The effect is that the field { "MAGIC" : 8*5 : string } could be created by calling set_int_expr field "MAGIC".

val set_expr : expr field ->
       expr ->
       expr field

Sets the expression field to an arbitrary OCaml expression.

val get_patt : patt field ->
       patt

Get the pattern from a pattern field.

val get_expr : expr field ->
       expr

Get the expression from an expression field.

val get_length : 'a field -> expr

Get the length in bits from a field. Note that what is returned is an OCaml expression, since lengths can be non-constant.

type endian_expr = 

val get_endian : 'a field -> endian_expr

Get the endianness of a field. This is an Bitstring_persistent.endian_expr which could be a constant or an OCaml expression.

val get_signed : 'a field -> bool

Get the signedness of a field.

type field_type = 

val get_type : 'a field -> field_type

Get the type of a field, Int, String or Bitstring.

val get_location : 'a field -> loc_t

Get the source code location of a field.

val get_offset : 'a field -> expr option

Get the offset expression of a field, or None if there is none.

val get_check : 'a field -> expr option

Get the check expression of a field, or None if there is none.

val get_bind : 'a field -> expr option

Get the bind expression of a field, or None if there is none.

val get_save_offset_to : 'a field -> patt option

Get the save_offset_to pattern of a field, or None if there is none.