anchor.diff:  
   
   -export_type([t/0,
  -              app_descriptor/0,
                 releases/0,
                 cmd_args/0]).
   
  
positive.code: %%============================================================================
  %% types
  %%============================================================================
  
  -type app_descriptor() :: {rcl_release:app_name(), rcl_release:app_vsn(), file:name()}.
  
  -type releases() :: ec_dictionary:dictionary({rcl_release:name(),
                                                rcl_release:vsn()},
  
negative.code:                   config_files=[] :: [file:filename()],
                    goals=[] :: [depsolver:constraint()],
                    providers = [] :: [rcl_provider:t()],
                    available_apps = [] :: [rcl_app_info:t()],
                    default_release :: {rcl_release:name(), rcl_release:vsn()},
                    releases :: ec_dictionary:dictionary({ReleaseName::atom(),
                                                          ReleaseVsn::string()},
  