15.4.750  src/lib/global-controls/global-control-forms.pkg

## global-control-forms.pkg

# Compiled by:
#     src/lib/global-controls/global-controls.lib


stipulate
    package lst =  list;                                                        # list                          is from   src/lib/std/src/list.pkg
    package qht =  quickstring_hashtable;                                       # quickstring_hashtable         is from   src/lib/src/quickstring-hashtable.pkg
    package qs  =  quickstring__premicrothread;                                 # quickstring__premicrothread   is from   src/lib/src/quickstring--premicrothread.pkg
herein

    package global_control_forms {
        #
        #  Menu_Ranks are used for ordering help messages (lexical order) 
        #
        Menu_Slot =  List( Int );

        Global_Control(X)
            =
            GLOBAL_CONTROL
              {
                name: qs::Quickstring,                                          # Name of the control.

                get:       Void -> X,                                           # Return the control's value.
                menu_slot: Menu_Slot,                                           # Positions control in the control menu hierarchy.
                obscurity: Int,                                                 # Control's detail level; higher means more obscure.

                help:      String,                                              # Control's description.

                set:  Null_Or(X) -> Void -> Void                                # function to set the control's value;
                                                                                # it is delayed (error checking in 1st
                                                                                # stage, actual assignment in 2nd);
                                                                                # if the argument is NULL, then
                                                                                # the 2nd stage will restore the
                                                                                # value that was present during the
                                                                                # first stage.

              }

        withtype Global_Control_Set (X, Y)
            =
             qht::Hashtable
                 { control:  Global_Control(X),
                   info:     Y
                 };

        Value_Converter(X)                                                      # Conversion functions for control values.          =
          =
          { name_of_type:    String,
            from_string:  String -> Null_Or(X),
            to_string:    X -> String
          };

        fun menu_rank_gt  ranks
            =
            lst::compare_sequences  int::compare  ranks    ==    GREATER;
    };
end;


## COPYRIGHT (c) 2002 Bell Labs, Lucent Technologies
## Subsequent changes by Jeff Prothero Copyright (c) 2010-2015,
## released per terms of SMLNJ-COPYRIGHT.