Attributes

You can think of an attribute as something that an object has, or doesn’t have. It represents a simple YES/NO definition. Is the object open, can the object be locked, etc…

Predefined attributes

Unlike some properties, there are no predefined attributes created by the compiler, although there are some which are predefined by the standard libraries. You can define a maximum of 128 attributes, including those defined by the standard libraries. This is one of the Hugo Compiler’s hard limits (it can’t be changed). Using the alias command, you can get around this limitation. There are several attributes defined in the Hugo standard library (in the order shown under order defined) in the following table.

Attribute name	Attribute value	Order defined	Used for	Notes
active	14	17	Set if an object is active	(alias for switchedon)
already_listed	23	28	For library use.	(alias for workflag)
clothing	15	18	Set if an object can be worn
container	18	22	Set if an object can contain things (have something put in them).	Conflicts with platform (see below)
enterable	17	21	Set an object may be entered
female	05	07	Set if a character is female (default is male)
hidden	20	24	Set if an object is not listed
known	00	01	Set when an object is known by the player
light	11	13	Set if an object is/provides light
living	04	06	Set if an object is a character
lockable	08	10	Set if an object can be locked
locked	09	11	Set if an object is locked
mobile	16	20	Set if an object may be moved around.	(alias for worn)
moved	01	02	Set when an object has been moved	aliased by visited
open	07	09	Set if an object is open
openable	06	08	Set if an object can be opened
platform	19	23	Set if an object can contain things (have something put on them).	Conflicts with container (see below)
plural	03	05	Set for plural objects
quiet	21	25	Set if a container/platform is quiet (contents not initially listed).
readable	12	14	Set if an object can be read
special	24	29	For miscellaneous use.
static	02	04	Set for an object that cannot be taken
switchable	13	15	Set if an object can be switched on/off
switchedon	14	16	Set if an object is switched on
transparent	22	26	Set if an object is not opaque (it can be seen through.)
unfriendly	10	12	Set if a character is an opponent
visited	01	03	Set when a room has been visited	(alias for moved)
workflag	23	27	For library use.	aliased by already_listed
worn	16	19	Set if an object is being worn.	aliased by mobile

After the attributes mentioned in the above table, you have a total of 104 available (non-aliased) attributes left that you can define for your game.

New attribute definition

To define an attribute, use the attribute command attribute . For example, if an object in your game can be magic or not, you may create an attribute like so:

attribute magic

object lantern "Magic lantern"
{
    nouns "lantern", "light"
    adjectives "magic", "small"

    long_desc
    {
        "A small, magic lantern is sitting here."
    }

    is magic, light
}

Importance of proper object attribution

Several verb grammar tokens rely on attributes being set correctly. This means that even when you want your game to deny a specific command, the proper attribute needs to be set for it to work correctly. Imagine, if you will, a television set with the following before code:

Object TV "television"
{
    is static   !  Can't be moved

    before {
        object DoSwitchOff
        {
            "You'd turn off the tv, but you're pretty sure \"Wheel of Misfortune\" is on next."
            return true
        }
    }
}

Without the switchable attribute, >TURN OFF TV will get the response “You can’t do that with the television.” and all of your players will be left to wonder when- if ever- “Wheel of Misfortune” will air. Don’t do that to them. In this example, the second line of the definition should be changed to:

is static, switchable   !  Can't be moved, can be turned on

Aliases

Main Article: alias

If you need to define a lot of attributes and might run out of them, what you can do is define some attribute as an alias of another attribute. If there are two conditions that are mutually exclusive, or that they don’t apply to different classes of objects, then you can alias an existing attribute to something else. For example, let’s say you have an attribute called ‘broken’ to indicate the player broke something. This is only going to be used by an object that can be broken, so if you have a scenery object - like a radioactive boulder - that can’t be broken but has to glow, you could do the following:

attribute broken
attribute glow alias broken

Then the attributes ‘broken’ and ‘glow’ are the same attribute, and you can use them interchangeably.