Welcome to program "Small", a simple demonstration of Ada 95. Program "Small" implements a small text adventure game. This version of Small supports these commands:

• Basic commands "look" and "quit";
• Object manipulation commands "get X" and "drop X", as well as an "inventory" command that lists what you're carrying;
• Simple movement commands ("north", "south", "east", "west", "up", "down", and their one-letter abbreviations; these may optionally be preceded with "go").

You can see a sample run of program "Small".

Program Small is a part of the Lovelace Ada tutorial. You can access the master copy of Lovelace through the Web. You can read a more detailed description of how program Small was developed, including design rationale and a description of the general process used to develop it, as lesson 18 in Lovelace. You can access the master copy of lesson 18 through the Web.

Program Small has a number of different packages that implement different types. At the heart of program Small is a set of types that implements the interesting "things" in the simulated world. To the right is a graphic showing the object-oriented hierarchy of the various types. All things in the simulated world are a "Thing"; a Thing can be a Room or an Occupant, an Occupant can be an Item or a Creature, and a Creature can be a Player or a Monster. Each of these types is contained in an Ada package with the plural name (type Thing is defined in package Things, etc.).

Program Small is implemented as the following program units:

• procedure Small (body) - main driver. Loops for input until "quit" is entered, and then passes that input on to the Parser.
• package Parser (spec) (body) - parses a string and then calls the appropriate routines in World, Things, and Occupants.
• package World (spec) (body) - sets up the "World" and keeps track of the current player.
• package Things (spec) (body) - defines type "Thing"; everything in the world is a Thing; Things can have a Name, a Description, and can contain other Things.
  • package Rooms (spec) (body) - defines type "Room"; you may be able to go north/south/etc from a Room.
  • package Occupants (spec) (body) - an Occupant is a Thing that may be inside a Room.
    • package Items (spec) - an Item is an inactive Occupant (like a box, knife, chair, etc.).
    • package Creatures (spec) - a Creature is an active Occupant.
      • package Players (spec) - a Player is a user.
      • package Monsters (spec) - a Monster is a Creature that's not a Player (like a dragon, bartender, etc.).
• package Direction (spec) (body) - this defines the type "Direction" which can have the values North, South, East, West, Up, and Down.
• package Ustrings (spec) (body) - utility routines for Unbounded_String.

All of the compilation units above can be selected; useful starting points include:

• procedure Small's body (the main driver)
• package Parser's body
• package Occupants' spec
• package Things' spec

A shorter, simple list of these compilation units is also available.

You can versions of program "Small" for your experimentation in many ways:

• You can see all of program Small's source code in one text file.
• You can get the zip file containing just the Small source code. In this zip file, each compilation unit is in a different file and the filenames follow the GNAT Ada compiler "krunched" filename conventions. If you plan to take program Small and modify it, this is probably the easiest way to get started.
• You can get everything in program Small in one zip file; this contains the the Small source code, the hypertext versions of that source code, the hypertext Small home page, and the Lovelace lesson describing program Small.

You are free to copy and modify program Small as you see fit, and you can use Small in any way you want, commercial or not. I've submitted program "Small" as an entry to the ARA Ada programming contest. The ARA requires that I grant them the copyright to Small, so I've granted program Small's copyright to the ARA under the condition that the ARA in term make Small freely available to the public without restriction (per the ARA's intent). However, please clearly credit me, David A. Wheeler, as the original developer of Small if you do anything with program Small. I think you'll agree that's a reasonable request.