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Get me outta here! (Directions)

Feeling stir crazy in the Boring Room? Want to stretch your legs? Let's go for it! Let's double the room count of our game! Add the following object definition after RedButton:

Object   InterestingRoom "Interesting Room"
   with  name "painting" "picture",
         description "What makes this room interesting? Well, for starters,
         it's a different room! There's also a picture hanging on one wall,
         but it's not a very interesting picture.",
         e_to BoringRoom
   has   light;

Now add a comma to the end of the description property of BoringRoom and this line before the has clause:

         w_to InterestingRoom

Compile and run. Enjoy your newfound freedom. After you get tired of going east and west over and over again (which should take about five seconds), quit the game and let's look at what we did.

Directions are specified as properties

It's that simple. If you want one room to be connected to another via one of the ten basic directions, simply use that direction's abbreviation + "_to" as the property name and the name of the destination room's constant as the value.

Directions are implemented as objects

And there are actually twelve of them. Here is a list of the directions and their corresponding objects and properties:

Direction Object Property

north n_obj n_to

south s_obj s_to

east e_obj e_to

west w_obj w_to

northeast ne_obj ne_to

southeast se_obj se_to

northwest nw_obj nw_to

southwest sw_obj sw_to

up u_obj u_to

down d_obj d_to

in in_obj in_to

out out_obj out_to

Direction	Object	Property
north	`n_obj`	`n_to`
south	`s_obj`	`s_to`
east	`e_obj`	`e_to`
west	`w_obj`	`w_to`
northeast	`ne_obj`	`ne_to`
southeast	`se_obj`	`se_to`
northwest	`nw_obj`	`nw_to`
southwest	`sw_obj`	`sw_to`
up	`u_obj`	`u_to`
down	`d_obj`	`d_to`
in	`in_obj`	`in_to`
out	`out_obj`	`out_to`

in and out are special, and you normally don't include them as available directions. out is automatically provided if the player is inside or on top of an object. How do you allow the player to get in (or on) an object? Give the object enterable. (You must also give it supporter if you want the player to be able to get on it instead of in it.)

The directions are all children of the compass object. They can be removed from this object, and new directions can be added. I won't cover that in this guide, but be aware that it can be done.

Why make directions objects?

Directions are objects so that they can be tested. For example, when a player types "NORTH," or simply "N," Inform generates the action <Go n_obj>. We haven't covered actions yet, but trust me that Go is the verb and n_obj is the first noun, which is stored in a variable called noun. When the player enters a room, code attached to that room object can check to see which direction the player used to enter the room. Let's say there is a trap door in the south end of a room. If the player enters the room from the south, that is, the player went north from the room he was in, the room can see that a <Go n_obj> action brought the player here and it can dump him into the dungeon.

You can't get there from here

Remember that computers do only what you tell them. Just because you can go west from the Boring Room into the Interesting Room, the game doesn't know (or assume) that you can go east from the Interesting Room to the Boring Room unless you specifically say so. That's why we added the w_to property to BoringRoom.

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