(** Configuration repository for HELM applications.
*
- * key ::= path
- * path ::= component ( '.' component )*
- * component ::= ( alpha | num | '_' )+
+ * ++ Keys format ++
*
- * Suggested usage <application>.<setting>:
- * e.g. gTopLevel.prooffile, http_getter.port, ...
+ * key ::= path
+ * path ::= component ( '.' component )*
+ * component ::= ( lowercase_alpha | num | '_' )+
+ * # with the only exception that sequences of '_' longer than 1 aren't valid
+ * # components
*
- * Configuration file example:
+ * 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:
+ * - the whole key is uppercased
+ * - each "." is converted to "__"
+ * E.g.: my.foo_ish.application -> MY__FOO_ISH__APPLICATION
*)
(** raised when a looked up key can't be found
(** raised when an error is encountered while parsing a configuration file
* @param fname file name
- * @param lno line number *)
-exception Parse_error of string * int
+ * @param line line number
+ * @param col column number
+ * @param msg error description
+ *)
+exception Parse_error of string * int * int * string
(** raised when a given <key,value> pair fails validity test(s)
* @param pair <key,value> pair
* 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
* parsing of an integer number from ; strings list to the splitting at blanks
* of it (heading and trailing blanks are removed before splitting) *)
+val get_string: string -> string (* alias for bare "get" above *)
val get_int: string -> int
val get_float: string -> float
val get_string_list: string -> string list
+ (* alias for bare "set" above *)
+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_string_list: key:string -> value:string list -> unit