House 1 Inform Tutorial

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In 1998, David Cornelson put together a set of Inform 6 source files that would help beginners with their interactive fiction education. They are recreated here.

Jump to any of the source code examples: Tutorial 1 | Tutorial 2 | Tutorial 3 | Tutorial 4 | Tutorial 5 | Tutorial 6 | Tutorial 7 | Tutorial 8

Return to main article: House Tutorial (Inform)

   ! ------------------------------------------------------------------------------
   ! Inform for New Writers
   ! The House - Version 1
   ! Last Modified: David Cornelson - 03-Jan-1998
   ! This work is freely offered to the Public Domain. - DAC 12-12-2015
   ! ------------------------------------------------------------------------------
   ! Q: What are these lines that begin with exclamation points?
   ! A: In an Inform program, you may want to place comments or notes before
   !    portions of code so that when you make changes, you will remember what
   !    you were thinking when you originally wrote the code. It's a great way
   !    to "document" your program so that others can understand it as well.
   !    Any characters following an exclamation point is considered a comment.
   !    The comment ends when you move to a new line.
   ! The constant "Story" contains the name of your story, in this case,
   ! "The House". The word "Constant" is an Inform statement that signifies that
   ! a token (variable) will have a single, unchangable value within the program.
   ! "Story" is the token name and "The House" is the value. Anytime you reference
   ! "Story" in your program, it will have the value "The House".
   ! The double-quote is used to represent a "string". A string is a type of data that
   ! contains letters and words. (As opposed to numbers). A string must begin with
   ! a double-quote and end with a double-quote.
   ! The semi-colon tells Inform that this statement is complete. You need a
   ! semi-colon to end all Inform statements.
   Constant Story "The House";
   ! The constant "Headline" contains the initial banner at the beginning of your
   ! game. In this Headline, there are three separate lines.
   ! The first line is "Inform for New Writers"
   ! The second line is "The House - Version 1"
   ! The third line is "By New Writer (1998) - Last Compiled: 03-Jan-1998"
   ! The carat "^" character is used to tell Inform that you want to move to a new
   ! line. This is called the newline character. Each time the newline character is
   ! placed into a string, the game will move to a new line.
   ! Here is another example:
   !      print "Once upon a time^there was a little bear^^that was all alone.^";
   ! This example will be printed on your screen as...
   !      Once upon a time
   !      there was a little bear
   !      that was all alone.
   ! Each newline character caused a break in the text and started at the beginning
   ! of a new line.
   Constant Headline
              "^Inform for New Writers^
                The House - Version 1^
                By New Writer (1998) - Last Compiled: 03-Jan-1998^";
   ! This constant tells Inform what the maximum score of your game will be.
   ! Currently, we have it set to 100.
   Constant MAX_SCORE 100;
   ! This constant is the last compile date and can be set by the Inform compiler.
   Serial "980103";
   ! This constant is set by you and tells which release of your game you are
   ! working on. It's a good idea to make backups of your program on a regular
   ! basis. When you have completed your game, start incrementing the Release value
   ! every time you fix bugs or make changes so that players know which release
   ! works and which one doesn't.
   Release 1;
   ! The Include statement allows Inform to open other files that are important to
   ! your program. The following files, "Parser" and "VerbLib" are the foundation
   ! of the Inform parser. DON'T REMOVE THESE LINES!!!
   Include "Parser";
   Include "VerbLib";
   ! Initialise
   ! The following "function" is the first portion of code executed by Inform when
   ! your game is played. You want to place a statement in this function that will
   ! set the first location of the player. We will add more to this section in later
   ! versions of "The House".
   ! FUNCTIONS: Portions of your code will will be in what are called "functions".
   !            The syntax of a function is as follows:
   !                        [ function_name argument argument;
   !                          ...your code...
   !                          ...your code...
   !                          ...your code...
   !                        ];
   !            Arguments are values passed when calling the function. More
   !            information on functions is available in later versions of
   !            "The House".
   [ Initialise;
   ! Our first location is the Sidewalk. Inform has a variable that we can set that
   ! just happens to be named "location".
   ! Sidewalk is a location, but in Inform it is an "Object". When we define the
   ! object Sidewalk it will have a unique value associated with it. So, when we
   ! set location equal to Sidewalk, the location variable now contains the object
   ! value of Sidewalk.
   location = Sidewalk;
   ! The following function is called by Inform when the player types SCORE or when
   ! the player ends the game. As you can see, each range of points has a different
   ! string printed. You can modify this function to suit your own story. Remember,
   ! the constant MAX_SCORE contains the value that is used by Inform to represent
   ! "You have scored <score> out of <MAX_SCORE>", so you want both the Constant
   ! and this function to be synchronized.
   [ PrintRank;
     print ", earning you the rank of ";
     if (score >= 100) "the greatest.";
     if (score >= 80) "above average.";
     if (score >= 60) "average.";
     if (score >= 40) "below average.";
     if (score >= 20) "the barely living.";
     "the living dead.";
   ! ----------------------------------------------------------------------------
   ! Locations
   ! In this section we will define our locations. These are "Objects" to Inform
   ! and contain the following elements.
   ! - object name
   !   The object name represents the variable or handle of the object.
   ! - short description
   !   The short description is the description printed in bold before the
   !   normal description.
   ! - initial description
   !   The initial description is printed only once when the location is first
   !   entered by the player.
   ! - normal description
   !   The normal description is printed everytime the player enters the location.
   ! - directional properties (tells which direction player can move) (optional)
   !   These include n_to, ne_to, e_to, up_to, in_to, etc. and are followed by
   !   another location object name.
   ! - properties
   !   Properties are functions that you can add to an object that help determine
   !   events and actions.
   ! - attributes
   !   Attributes are True/False values that help you remember certain states of
   !   an object or event, such as whether the lights are on or not. The positive
   !   value is represented as "light" and the negative would be "~light". There
   !   are standard attributes used by Inform and you can add your own as well.
   ! Actually, there's more than this, but we'll add the complicated stuff later!
   ! ----------------------------------------------------------------------------
   ! Define the object "Sidewalk"
   ! Object Name: Sidewalk
   ! Short Description: "Sidewalk"
   ! Initial Description: none
   ! Normal Description: "You are standing on the sidewalk in front of a house."
   ! Attributes: light
   ! The Sidewalk is the first location of our game and includes a description
   ! and when we enter it, it will have light.
   Object Sidewalk "Sidewalk"
       with  description
             "You are standing on the sidewalk in front of a house.",
       has   light;
   ! ----------------------------------------------------------------------------
   ! Grammar
   ! The grammar section includes the file "Grammar" and will later include
   ! extensions to the standard grammar library.
   ! ----------------------------------------------------------------------------
   Include "Grammar";
   ! ----------------------------------------------------------------------------
   ! Compilation Results
   ! ----------------------------------------------------------------------------
   ! Command: INFRMW32 -J HOUSE01.INF
   ! PC/Win32 Inform 6.14 (8th September 1997)
   !   6 "compass"
   !   7 "north wall"
   !   8 "south wall"
   !   9 "east wall"
   !  10 "west wall"
   !  11 "northeast wall"
   !  12 "northwest wall"
   !  13 "southeast wall"
   !  14 "southwest wall"
   !  15 "ceiling"
   !  16 "floor"
   !  17 "outside"
   !  18 "inside"
   !  19 "(darkness object)"
   !  20 "(self object)"
   !  21 "(Inform Parser)"
   !  22 "(Inform Library)"
   !  23 "(with no short name)"
   !  24 "Sidewalk"