Welcome to program "Small", a demonstration of the Ada 95 programming language. 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.

Below is a brief description of program small, with hypertext links to the various compilation units in program Small. The compilation units have a large number of hypertext links between each other, making it easier to follow the program (these links were generated by my program ada2html).

The Design of Small

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.

How to Start Experimenting with Small

• 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.

How to Compile Small

If you're using GNAT, it's easiest to compile using "gnatmake", which will automatically figure out what needs compiling and in what order, then compile the files for you. You have two choices in this case: using short filenames or long filenames:

1. The "zip" files the filenames are all "krunched" down to 8 character filenames per MS-DOS and ISO CD-ROM requirements. Here's the GNAT incantation to tell your system to use 8-character limits:

         gnatmake small -cargs -gnatk8 -largs -gnatk8
   

2. If you're using GNAT but want to use long filenames (and your operating system supports them!), use the file "small.txt" (which puts all the source code in one file) and expand that file with the command:

         gnatchop small.txt
   

   Now you'll have a bunch of files with long names. You can then compile the files with:

         gnatmake small
   

Version and Legal Information

This is version 1.5 of "Small", which notes the change in location of "HBAP" to its new URL, "http://www.adahome.com/". Version 1.4 of "Small" fixed a small bug in the Parser (in file parser.adb line 28) and deleted a misleading comment in the specification for Occupant (in file occupant.ads line 36). Version 1.3 of "Small" added some documentation on how to compile Small. Version 1.2 of "Small" added the copyright statements for the ARA and made two small corrections in the body of package Rooms. Version 1.1 changed ada2html's location, so all Small hypertext pages were regenerated.

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. However, please give me credit for writing the original if you do anything with Small; I think you'll agree that's a reasonable request. Small was the first winner of the Ada Resource Association (ARA)'s Ada Lovelace programming contest. Small was submitted to the ARA as a December 15, 1995 entry. On request of the ARA, the following text was placed in each file:

--
-- Copyright (C) 1996 Ada Resource Association (ARA), Columbus, Ohio.
-- Author: David A. Wheeler
--

--
-- Permission to use, copy, modify, and distribute this software and its
-- documentation for any purpose and without fee is hereby granted,
-- provided that the above copyright and authorship notice appear in all
-- copies and that both that copyright notice and this permission notice
-- appear in supporting documentation.
-- 
-- The ARA makes no representations about the suitability of this software
-- for any purpose.  It is provided "as is" without express
-- or implied warranty.
--