- added sample usage of get_opt method

[helm.git] / helm / ocaml / registry / helm_registry.mli

diff --git a/helm/ocaml/registry/helm_registry.mli b/helm/ocaml/registry/helm_registry.mli
index 668525b86a13e49f034df503d782a0fba9915e34..1f40b5453fa0e352b859e352b41b4b9426d53c23 100644 (file)
--- a/helm/ocaml/registry/helm_registry.mli
+++ b/helm/ocaml/registry/helm_registry.mli
@@ -54,12 +54,25 @@
  *  - the whole key is uppercased
  *  - 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
    * @param expected_type
    * @param value
@@ -91,22 +104,51 @@ exception Invalid_value of (string * string) * string
 val get: string -> string
 val set: key:string -> value:string -> unit
 
+  (** 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
+
 (** {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) *)
 
-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
+val get_string:       string -> string  (* alias for bare "get" above *)
+val get_int:          string -> int
+val get_float:        string -> float
+val get_bool:         string -> bool
+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
+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
+val set_string_list:  key:string -> value:string list -> unit
+
+(** {3 Optional values interface}
+ * Functions below took as first argument respectively a "getter" and a "setter"
+ * function. A getter is one of the get_* function above, a setter is one of the
+ * set_* function above. Returned value is a get (set) function typed as the
+ * given getter (setter) whith optional values. None is returned for missing
+ * keys and None can be assigned to a key removing it from the registry.
+ *
+ * Sample  usage:
+ *
+ *  match Helm_registry.get_opt Helm_registry.get_int "foo.bar" with
+ *  | Some i -> ...
+ *  | None -> ...
+ *)
+
+val get_opt:
+  (string -> 'a) (* getter *) ->
+    string -> 'a option
+val set_opt:
+  (key:string -> value:'a -> unit) (* setter *) ->
+    key:string -> value:'a option -> unit
+val get_opt_default:  (* as get_opt with an additional default value *)
+  (string -> 'a) -> 'a -> string -> 'a
 
 (** {2 Validators}
  * Each key may have zero or more associated validators, that are predicates
@@ -132,14 +174,20 @@ val add_validator:
  * Validators aren't saved. load_from/save_to sequences don't preserve comments
  *)
 
-  (** @param fname file to which save current configuration *)
+  (** @param fname file to which save current configuration
+   * If xmllint is available then it will be used for pretty printing fname,
+   * otherwise fname will be in the usual pxp ugly format *)
 val save_to: string -> unit
 
-  (** @param fname file from which load new configuration *)
-val load_from: 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
 
-(*
 (* DEBUGGING *)
-val dump: unit -> unit
-*)
+(* val dump: unit -> unit *)