--- /dev/null
+(* Copyright (C) 2004-2005, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+(** Configuration repository for HELM applications.
+ *
+ * ++ Keys format ++
+ *
+ * key ::= path
+ * path ::= component ( '.' component )*
+ * component ::= ( alpha | num | '_' )+
+ * # with the only exception that sequences of '_' longer than 1 aren't valid
+ * # components
+ *
+ * Suggested usage <application>.<setting>:
+ * e.g. gTopLevel.prooffile, http_getter.port, ...
+ *
+ * ++ Configuration file example ++
+ *
+ * gTopLevel.prooffile = "/home/zack/prooffile"
+ * http_getter.port = "58080"
+ *
+ * ++ Environment variable override ++
+ *
+ * each key has an associated environment variable name. At runtime (i.e. when
+ * "get" requests are performed) a variable with this name will be looked for,
+ * if it's defined it will override the value present (or absent) in the
+ * registry.
+ * Environment variables are _not_ considered when saving the configuration to
+ * a configuration file (via "save_to" function below) .
+ *
+ * Mapping between keys and environment variables is as follows:
+ * - each "." is converted to "__"
+ * E.g.: my.Foo_iSH.Application -> my__Foo_iSH__Application
+ *
+ * ++ Variable interpolation ++
+ *
+ * Interpolation is supported with the following syntax:
+ *
+ * foo.bar = "quux"
+ * foo.baz = $(foo.bar)/baz
+ *)
+
+ (** raised when a looked up key can't be found
+ * @param key looked up key *)
+exception Key_not_found of string
+
+ (** raised when a cyclic definitions is found, e.g. after
+ * Helm_registry.set "a" "$b"
+ * Helm_registry.set "b" "$a"
+ * @param msg brief description of the definition cycle *)
+exception Cyclic_definition of string
+
+ (** raised when a looked up key doesn't have the required type, parameter is
+ * an error message *)
+exception Type_error of string
+
+ (** raised when a malformed key is encountered
+ * @param key malformed key *)
+exception Malformed_key of string
+
+ (** raised when an error is encountered while parsing a configuration file
+ * @param fname file name
+ * @param line line number
+ * @param col column number
+ * @param msg error description
+ *)
+exception Parse_error of string * int * int * string
+
+(** {2 Generic untyped interface}
+ * Using the functions below this module could be used as a repository of
+ * key/value pairs *)
+
+ (** lookup key in registry with environment variable override *)
+val get: string -> string
+val set: key:string -> value:string -> unit
+val has: string -> bool
+
+ (** remove a key from the current environment, next get over this key will
+ * raise Key_not_found until the key will be redefined *)
+val unset: string -> unit
+
+ (** @param interpolate defaults to true *)
+val fold:
+ ?prefix:string -> ?interpolate:bool ->
+ ('a -> string -> string -> 'a) -> 'a -> 'a
+
+ (** @param interpolate defaults to true *)
+val iter:
+ ?prefix:string -> ?interpolate:bool ->
+ (string -> string -> unit) -> unit
+
+ (** @param interpolate defaults to true *)
+val to_list:
+ ?prefix:string -> ?interpolate:bool ->
+ unit -> (string * string) list
+
+ (** @param prefix key representing the section whose contents should be listed
+ * @return section list * key list *)
+val ls: string -> string list * string list
+
+(** {2 Typed interface}
+ * Three basic types are supported: strings, int and strings list. Strings
+ * correspond literally to what is written inside double quotes; int to the
+ * parsing of an integer number from ; strings list to the splitting at blanks
+ * of it (heading and trailing blanks are removed before splitting) *)
+
+(** {3 Unmarshallers} *)
+
+val string: string -> string
+val int: string -> int
+val float: string -> float
+val bool: string -> bool
+
+(** {3 Typed getters} *)
+
+ (** like get, with an additional unmarshaller
+ * @param unmarshaller conversion function from string to the desired type.
+ * Use one of the above unmarshallers *)
+val get_typed: (string -> 'a) -> string -> 'a
+
+val get_opt: (string -> 'a) -> string -> 'a option
+val get_opt_default: (string -> 'a) -> default:'a -> string -> 'a
+
+ (** never fails with Key_not_found, instead return the empty list *)
+val get_list: (string -> 'a) -> string -> 'a list
+
+ (** decode values which are blank separated list of values, of length 2 *)
+val get_pair: (string -> 'a) -> (string -> 'b) -> string -> 'a * 'b
+
+(** {4 Shorthands} *)
+
+val get_string: string -> string
+val get_int: string -> int
+val get_float: string -> float
+val get_bool: string -> bool
+
+(** {3 Marshallers} *)
+
+val of_string: string -> string
+val of_int: int -> string
+val of_float: float -> string
+val of_bool: bool -> string
+
+(** {3 Typed setters} *)
+
+ (** like set, with an additional marshaller
+ * @param marshaller conversion function to string.
+ * Use one of the above marshallers *)
+val set_typed: ('a -> string) -> key:string -> value:'a -> unit
+
+val set_opt: ('a -> string) -> key:string -> value:'a option -> unit
+val set_list: ('a -> string) -> key:string -> value:'a list -> unit
+
+(** {4 Shorthands} *)
+
+val set_string: key:string -> value:string -> unit
+val set_int: key:string -> value:int -> unit
+val set_float: key:string -> value:float -> unit
+val set_bool: key:string -> value:bool -> unit
+
+(** {2 Persistent configuration} *)
+
+ (** @param fname file to which save current configuration *)
+val save_to: string -> unit
+
+ (** @param fname file from which load new configuration. If it's an absolute
+ * file name "path" argument is ignored.
+ * Otherwise given file name is looked up in each directory member of the
+ * given path. Each matching file is loaded overriding previous settings. If
+ * no path is given a default path composed of just the current working
+ * directory is used.
+ *)
+val load_from: ?path:string list -> string -> unit
+
+ (** removes all keys *)
+val clear: unit -> unit
+