Module Sexplib.Sexp

Sexp: Module for handling S-expressions (I/O, etc.)

include Sexp_intf.S
type t = Type.t =
| Atom of string
| List of t list

Type of S-expressions

type bigstring = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t

Type of bigstrings

val compare : t ‑> t ‑> int
Defaults
val default_indent : int Pervasives.ref

default_indent reference to default indentation level for human-readable conversions. Initialisation value: 2.

S-expression size
val size : t ‑> int * int

size sexp returns (n_atoms, n_chars), where n_atoms is the number of atoms in S-expression sexp, and n_chars is the number of characters in the atoms of the S-expression.

Scan functions
val scan_sexp : ?⁠buf:Buffer.t ‑> Lexing.lexbuf ‑> t

scan_sexp ?buf lexbuf scans an S-expression from lex buffer lexbuf using the optional string buffer buf for storing intermediate strings.

val scan_sexps : ?⁠buf:Buffer.t ‑> Lexing.lexbuf ‑> t list

scan_sexps ?buf lexbuf reads a list of whitespace separated S-expressions from lex buffer lexbuf using the optional string buffer buf for storing intermediate strings.

val scan_rev_sexps : ?⁠buf:Buffer.t ‑> Lexing.lexbuf ‑> t list

scan_rev_sexps ?buf lexbuf same as scan_sexps, but returns the reversed list and is slightly more efficient.

val scan_sexp_opt : ?⁠buf:Buffer.t ‑> Lexing.lexbuf ‑> t option

scan_sexp_opt ?buf lexbuf is equivalent to scan_sexp ?buf lexbuf except that it returns None when the eof is reached.

val scan_iter_sexps : ?⁠buf:Buffer.t ‑> f:(t ‑> unit) ‑> Lexing.lexbuf ‑> unit

scan_iter_sexps ?buf ~f lexbuf iterates over all whitespace separated S-expressions scanned from lex buffer lexbuf using function f, and the optional string buffer buf for storing intermediate strings.

val scan_fold_sexps : ?⁠buf:Buffer.t ‑> f:('a ‑> t ‑> 'a) ‑> init:'a ‑> Lexing.lexbuf ‑> 'a

scan_fold_sexps ?buf ~f ~init lexbuf folds over all whitespace separated S-expressions scanned from lex buffer lexbuf using function f, initial state init, and the optional string buffer buf for storing intermediate strings.

val scan_sexps_conv : ?⁠buf:Buffer.t ‑> f:(t ‑> 'a) ‑> Lexing.lexbuf ‑> 'a list

scan_sexps_conv ?buf ~f lexbuf maps all whitespace separated S-expressions scanned from lex buffer lexbuf to some list using function f, and the optional string buffer buf for storing intermediate strings.

Type and exception definitions for (partial) parsing
module Parse_pos : sig ... end
module Cont_state : sig ... end
type ('a, 't) parse_result = ('a, 't) Pre_sexp.parse_result =
| Done of 't * Parse_pos.t

(** Done (t, parse_pos) finished parsing an S-expression. Current parse position is parse_pos. *)

| Cont of Cont_state.t * ('a, 't) parse_fun

(** Cont (cont_state, parse_fun) met the end of input before completely parsing an S-expression. The user has to call parse_fun to continue parsing the S-expression in another buffer. cont_state is the current parsing state of the continuation. NOTE: the continuation may only be called once and will raise Failure otherwise! *)

Type of result from calling Sexp.parse.

type ('a, 't) parse_fun = pos:int ‑> len:int ‑> 'a ‑> ('a, 't) parse_result

Type of parsing functions with given offsets and lengths.

module Annotated : sig ... end

Module for parsing S-expressions annotated with location information

type 't parse_state = private 't Pre_sexp.parse_state = {
parse_pos : Parse_pos.t;

(** Current parse position *)

}

Type of state maintained during parsing

type parse_error = Pre_sexp.parse_error = {
err_msg : string;

(** Reason why parsing failed *)

parse_state : [ `Sexp of t list list parse_state | `Annot of Annotated.stack parse_state ];

(** State of parser *)

}

Type of parse errors

exception Parse_error of parse_error

Exception raised during partial parsing

Unannotated (partial) parsing
val parse : ?⁠parse_pos:Parse_pos.t ‑> ?⁠len:int ‑> string ‑> (string, t) parse_result

parse ?parse_pos ?len str (partially) parses an S-expression in string buffer str starting out with position information provided in parse_pos and reading at most len characters. To parse a single atom that is not delimited by whitespace it is necessary to call this function a second time with the returned continuation, and a dummy buffer that contains whitespace.

parse starts parsing str at position parse_pos.buf_pos. Each subsequent parse_fun from a Cont uses the buf and pos that is supplied to it. The final parse_fun that returns Done mutates the buf_pos in the originally supplied parse_pos, and then returns it.

  • Parameter parse_pos: default = Parse_pos.create ()
  • Parameter len: default = String.length str - parse_pos.Parse_pos.buf_pos
val parse_bigstring : ?⁠parse_pos:Parse_pos.t ‑> ?⁠len:int ‑> bigstring ‑> (bigstring, t) parse_result

parse_bigstring ?parse_pos ?len str same as parse, but operates on bigstrings.

val input_sexp : ?⁠parse_pos:Parse_pos.t ‑> Pervasives.in_channel ‑> t

input_sexp ?parse_pos ic parses an S-expression from input channel ic using initial position information in parse_pos. NOTE: this function is not as fast on files as Sexp.load_sexp, and is also slightly slower than the scan-functions. But it is guaranteed that input_sexp is only going to read data parseable as an S-expression. Thus, subsequent input functions will see the data immediately following it.

  • Parameter parse_pos: default = Parse_pos.create ()
val input_sexps : ?⁠parse_pos:Parse_pos.t ‑> ?⁠buf:bytes ‑> Pervasives.in_channel ‑> t list

input_sexps ?parse_pos ?buf ic parses whitespace separated S-expressions from input channel ic until EOF is reached. Faster than the scan-functions.

  • Parameter parse_pos: default = Parse_pos.create ()
val input_rev_sexps : ?⁠parse_pos:Parse_pos.t ‑> ?⁠buf:bytes ‑> Pervasives.in_channel ‑> t list

input_rev_sexps ?parse_pos ?buf ic same as Sexp.input_sexps, but returns a reversed list of S-expressions, which is slightly more efficient.

Loading of (converted) S-expressions
val load_sexp : ?⁠strict:bool ‑> ?⁠buf:bytes ‑> string ‑> t

load_sexp ?strict ?buf file reads one S-expression from file using buffer buf for storing intermediate data. Faster than the scan-functions.

  • Raises Parse_error: if the S-expression is unparseable.
  • Raises Failure: if parsing reached the end of file before one S-expression could be read.
  • Raises Failure: if strict is true and there is more than one S-expression in the file.
  • Parameter strict: default = true
val load_sexps : ?⁠buf:bytes ‑> string ‑> t list

load_sexps ?buf file reads a list of whitespace separated S-expressions from file using buffer buf for storing intermediate data. Faster than the scan-functions.

  • Raises Parse_error: if there is unparseable data in the file.
  • Raises Failure: if parsing reached the end of file before the last S-expression could be fully read.
val load_rev_sexps : ?⁠buf:bytes ‑> string ‑> t list

load_rev_sexps ?buf file same as Sexp.load_sexps, but returns a reversed list of S-expressions, which is slightly more efficient.

val load_sexp_conv : ?⁠strict:bool ‑> ?⁠buf:bytes ‑> string ‑> (t ‑> 'a) ‑> 'a Annotated.conv

load_sexp_conv ?strict ?buf file f like Sexp.load_sexp, but performs a conversion on the fly using f. Performance is equivalent to executing Sexp.load_sexp and performing conversion when there are no errors. In contrast to the plain S-expression loader, this function not only performs the conversion, it will give exact error ranges for conversion errors.

  • Raises Parse_error: if there is unparseable data in the file.
  • Raises Failure: if parsing reached the end of file before the last S-expression could be fully read.
val load_sexp_conv_exn : ?⁠strict:bool ‑> ?⁠buf:bytes ‑> string ‑> (t ‑> 'a) ‑> 'a

load_sexp_conv_exn ?strict ?buf file f like load_sexp_conv, but returns the converted value or raises Of_sexp_error with exact location information in the case of a conversion error.

val load_sexps_conv : ?⁠buf:bytes ‑> string ‑> (t ‑> 'a) ‑> 'a Annotated.conv list

load_sexps_conv ?buf file f like Sexp.load_sexps, but performs a conversion on the fly using f. Performance is equivalent to executing Sexp.load_sexps and performing conversion when there are no errors. In contrast to the plain S-expression loader, this function not only performs the conversion, it will give exact error ranges for conversion errors.

  • Raises Parse_error: if there is unparseable data in the file.
  • Raises Failure: if parsing reached the end of file before the last S-expression could be fully read.
val load_sexps_conv_exn : ?⁠buf:bytes ‑> string ‑> (t ‑> 'a) ‑> 'a list

load_sexps_conv_exn ?buf file f like load_sexps_conv, but returns the converted value or raises Of_sexp_error with exact location information in the case of a conversion error.

Output of S-expressions to I/O-channels

NOTE: for performance reasons these output functions may need to allocate large strings to write out huge S-expressions. This may cause problems on 32-bit platforms. If you think that you may need to write huge S-expressions on such platforms, you might want to use the pretty-printers that write to formatters instead (see further below).

val output_hum : Pervasives.out_channel ‑> t ‑> unit

output_hum oc sexp outputs S-expression sexp to output channel oc in human readable form.

val output_hum_indent : int ‑> Pervasives.out_channel ‑> t ‑> unit

output_hum_indent indent oc sexp outputs S-expression sexp to output channel oc in human readable form using indentation level indent.

val output_mach : Pervasives.out_channel ‑> t ‑> unit

output_mach oc sexp outputs S-expression sexp to output channel oc in machine readable (i.e. most compact) form.

val output : Pervasives.out_channel ‑> t ‑> unit

output oc sexp same as output_mach.

Output of S-expressions to file

All save-functions write to a temporary file before moving it into place to avoid intermittent garbling of existing files, which may cause problems for other processes that try to read.

val save_hum : ?⁠perm:int ‑> string ‑> t ‑> unit

save_hum ?perm file sexp outputs S-expression sexp to file in human readable form.

  • Parameter perm: default = umask
val save_mach : ?⁠perm:int ‑> string ‑> t ‑> unit

save_mach ?perm file sexp outputs S-expression sexp to file in machine readable (i.e. most compact) form.

  • Parameter perm: default = umask
val save : ?⁠perm:int ‑> string ‑> t ‑> unit

save ?perm file sexp same as save_mach.

val save_sexps_hum : ?⁠perm:int ‑> string ‑> t list ‑> unit

save_sexps_hum ?perm file sexps outputs S-expression list sexps to file in human readable form, each sexp being followed by a newline.

  • Parameter perm: default = umask
val save_sexps_mach : ?⁠perm:int ‑> string ‑> t list ‑> unit

save_sexps_mach ?perm file sexps outputs S-expression list sexps to file in machine readable form, each sexp being followed by a newline.

  • Parameter perm: default = umask
val save_sexps : ?⁠perm:int ‑> string ‑> t list ‑> unit

save_sexps ?perm file sexp same as save_sexps_mach.

Output of S-expressions to formatters
val pp_hum : Format.formatter ‑> t ‑> unit

pp_hum ppf sexp outputs S-expression sexp to formatter ppf in human readable form.

val pp_hum_indent : int ‑> Format.formatter ‑> t ‑> unit

pp_hum_indent n ppf sexp outputs S-expression sexp to formatter ppf in human readable form and indentation level n.

val pp_mach : Format.formatter ‑> t ‑> unit

pp_mach ppf sexp outputs S-expression sexp to formatter ppf in machine readable (i.e. most compact) form.

val pp : Format.formatter ‑> t ‑> unit

pp ppf sexp same as pp_mach.

String and bigstring conversions
module Of_string_conv_exn : sig ... end

Module encapsulating the exception raised by string converters when type conversions fail.

val of_string : string ‑> t

of_string str converts string str to an S-expression. NOTE: trailing whitespace is considered an error, which may be overly strict for some applications. Either strip the string of trailing whitespace first, or, even cheaper, use parse instead.

val of_string_conv : string ‑> (t ‑> 'a) ‑> 'a Annotated.conv

of_string_conv str conv like of_string, but performs type conversion with conv. returns conversion result.

val of_string_conv_exn : string ‑> (t ‑> 'a) ‑> 'a

of_string_conv_exn str conv like of_string_conv, but raises Of_string_conv_exn.E if type conversion fails. returns converted value.

val of_bigstring : bigstring ‑> t

of_bigstring bstr same as of_string, but operates on bigstrings.

val of_bigstring_conv : bigstring ‑> (t ‑> 'a) ‑> 'a Annotated.conv

of_bigstring_conv bstr conv like of_bigstring, but performs type conversion with conv. returns conversion result.

val of_bigstring_conv_exn : bigstring ‑> (t ‑> 'a) ‑> 'a

of_bigstring_conv_exn bstr conv like of_bigstring_conv, but raises Of_string_conv_exn.E if type conversion fails. returns converted value.

val to_string_hum : ?⁠indent:int ‑> t ‑> string

to_string_hum ?indent sexp converts S-expression sexp to a string in human readable form with indentation level indent.

  • Parameter indent: default = !default_indent
val to_string_mach : t ‑> string

to_string_mach sexp converts S-expression sexp to a string in machine readable (i.e. most compact) form.

val to_string : t ‑> string

to_string sexp same as to_string_mach.

Buffer conversions
val to_buffer_hum : buf:Buffer.t ‑> ?⁠indent:int ‑> t ‑> unit

to_buffer_hum ~buf ?indent sexp outputs the S-expression sexp converted to a string in human readable form to buffer buf.

  • Parameter indent: default = !default_indent
val to_buffer_mach : buf:Buffer.t ‑> t ‑> unit

to_buffer_mach ~buf sexp outputs the S-expression sexp converted to a string in machine readable (i.e. most compact) form to buffer buf.

val to_buffer : buf:Buffer.t ‑> t ‑> unit

to_buffer ~buf sexp same as to_buffer_mach.

val to_buffer_gen : buf:'buffer ‑> add_char:('buffer ‑> char ‑> unit) ‑> add_string:('buffer ‑> string ‑> unit) ‑> t ‑> unit

to_buffer_gen ~buf ~add_char ~add_string sexp outputs the S-expression sexp converted to a string to buffer buf using the output functions add_char and add_string.

Utilities for automated type conversions
val unit : t

unit the unit-value as expressed by an S-expression.

val is_unit : t ‑> bool
val sexp_of_t : t ‑> t

sexp_of_t sexp maps S-expressions which are part of a type with automated S-expression conversion to themselves.

val t_of_sexp : t ‑> t

t_of_sexp sexp maps S-expressions which are part of a type with automated S-expression conversion to themselves.

Utilities for conversion error handling
type found = [
| `Found
| `Pos of int * found
]

Type of successful search results. `Found means that an S-expression was found at the immediate position, and `Pos (pos, found) indicates that it was found at position pos within a structure (= S-expression list) where found describes recursively where it was found in that structure.

type search_result = [
| `Not_found
| found
]

Type of search results. `Not_found means that an S-expression was not found within another S-expression.

val search_physical : t ‑> contained:t ‑> search_result

search_physical sexp ~contained returns the search result indicating whether, and if, where the S-expression contained was found within S-expression sexp.

val subst_found : t ‑> subst:t ‑> found ‑> t

subst_found sexp ~subst found returns the S-expression that results from substituting subst within S-expression sexp at the location described by found.

module With_layout : sig ... end

S-expressions annotated with relative source positions and comments