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"