Config::Structured - Provides generalized and structured configuration
    value access


    version 2.002


    Basic usage:

      use Config::Structured;
      my $conf = Config::Structured->new(
        structure    => { ... },
        config       => { ... }
      say $conf->some->nested->value();

    Hooks exammple showing how to ensure config directories exist prior to
    first use:

      my $conf = Config::Structured->new(
        hooks => {
          '/paths/*' => {
            on_load => sub($node,$value) {


      L<Config::Structured> provides a structured method of accessing configuration values
      This is predicated on the use of a configuration C<structure> (required), This structure
      provides a hierarchical structure of configuration branches and leaves. Each branch becomes
      a L<Config::Structured> method which returns a new L<Config::Structured> instance rooted at
      that node, while each leaf becomes a method which returns the configuration value.
      The configuration value is normally provided in the C<config> hash. However, a C<config> node
      for a non-Hash value can be a hash containing the "source" and "ref" keys. This permits sourcing
      the config value from a file (when source="file") whose filesystem location is given in the "ref"
      value, or an environment variable (when source="env") whose name is given in the "ref" value.
      I<Structure Leaf Nodes> are required to include an "isa" key, whose value is a type 
      (see L<Moose::Util::TypeConstraints>). If typechecking is not required, use isa => 'Any'.
      There are a few other keys that L<Config::Structured> respects in a leaf node:
      =item C<default>
      This key's value is the default configuration value if a data source or value is not provided by
      the configuation.
      =item C<description>
      =item C<notes>
      A human-readable description and implementation notes, respectively, of the configuration node. 
      L<Config::Structured> does not do anything with these values at present, but they provides inline 
      documentation of configuration directivess within the structure (particularly useful in the common 
      case where the structure is read from a file)
      Besides C<structure> and C<config>, L<Config::Structured> also accepts a C<hooks> argument at 
      initialization time. This argument must be a HashRef whose keys are patterns matching config
      node paths, and whose values are HashRefs containing C<on_load> and/or C<on_access> keys. These
      in turn point to CodeRefs which are run when the config value is initially loaded, or every time
      it is accessed, respectively.



    Class method.

    Returns a registered Config::Structured instance. If $name is not
    provided, returns the default instance. Instances can be registered
    with __register_default or __register_as. This mechanism is used to
    provide global access to a configuration, even from code contexts that
    otherwise cannot share data.


    Call on a Config::Structured instance to set the instance as the


    Call on a Config::Structured instance to register the instance as the
    provided name.


    Mark Tyrrell <>


    This software is copyright (c) 2019 by Concert Pharmaceuticals, Inc.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.