Module Release_config

module Release_config: sig .. end

This module provides an interface to configuration file parsing. Configuration files are assumed to be collections of key-value pairs possibly organized in sections.

Sections are started by a section name enclosed in square brackets. Keys and values are separated by an equals sign, and values can be integers, floats, booleans, strings, regular expressions, log levels or lists of one of those types, as defined by the Release_values.value type.

Keys must be named starting with a letter and optionally followed by any character except whitespace characters, square brackets, equals signs or hash signs.

Integers values are represented by sequences of digits and floats are represented by sequences of digits separated by a dot character.

Strings are sequences of characters enclosed by double quotes, and newline characters inside strings are supported.

Regular expressions are enclosed by forward slash characters and support the same constructs as the ones documented in OCaml's Str module, but the grouping constructs ( and ) and the alternative between expressions construct | don't need to be escaped by a backslash. Newlines can be inserted in regular expressions for organization purposes and are ignored along with any following whitespace characters.

Log levels are bare words matching the definitions in Lwt_log, that is, debug, info, notice, warning, error and fatal.

Finally, lists are sequences of the above types enclosed by square brackets and separated by commas.

In terms of code, configuration files are specified by the Release_config.spec type. This is simply a list of Release_config.sections, each containing lists of Release_config.keys. Keys are defined by their name, an optional default value and a list of validations. If a key has no default value and is absent from the configuration file, an error will be generated.

Validations are functions as defined by the Release_config_values.validation type. Many pre-defined validations are available in the Release_config_validations module.

type t 

The type of a configuration.

type key = string * Release_config_values.value option *
       Release_config_values.validation list 

The type of a configuration key specification. A key is specified by its name, a possible default value and a list of validations.

type section = [ `Global of key list
       | `Section of string * key list ] 

The type of a configuration section specification. A section specification contains a list of keys belonging to that section, and can either have a name or be global (in which case its keys will not appear under any section definitions in the configuration file).

type spec = section list 

The type of configuration file specifications.

val parse : Lwt_io.file_name ->
       spec ->
       [ `Configuration of t | `Error of string ] Lwt.t

Parse a configuration file. parse file spec will try to parse file and, if it is syntatically correct, validate it against the specification given in spec.

val defaults : spec -> t

defaults spec returns a configuration built from the default values of spec. This only makes sense if every key in the specification has a default value.

val get : t -> string -> string -> Release_config_values.value

get conf section key returns the value of the parameter key of section section in configuration conf.

val get_global : t -> string -> Release_config_values.value

get_global conf key returns the value of the global parameter key.