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<TR><TD Valign="top"><A HREF="contents.html">Contents</A> <A HREF="sectionA4.html">Back</A> <A HREF="sectionA6.html">Forward</A><TD bgcolor="#F5DEB3"><BLOCKQUOTE><H3>A5. Library attributes</H3></BLOCKQUOTE><TR><TD><TD>

Here is a concise account of all the normal rules concerning

all the library's attributes, except that: rules about how

the parser sorts out ambiguities are far too complicated to

include here, but should not concern designers anyway; and the

definitions of 'scope' and 'darkness' are given in

<A HREF="section28.html">Section 28</A> and <A HREF="section17.html">Section 17</A> respectively. These rules are the result

of pragmatism and compromise, but are all easily

modifiable.

<DT><TT>absent</TT><DD>

A 'floating object' (one with a

<TT>found_in</TT> property, which can appear in many different rooms)

which is <TT>absent</TT> will in future no longer appear in the game. Note that

you cannot make a floating object disappear merely by giving it

<TT>absent</TT>, but must explicitly <TT>remove</TT> it as well.

<DT><TT>animate</TT><DD>

"Is alive (human or animal).'' Can be spoken to in "richard, hello'' style;

matches the <TT>creature</TT> token in grammar; picks up "him'' or "her''

(according to gender) rather than "it'', likewise "his''; an object the

player is changed into becomes <TT>animate</TT>; some messages read "on whom'',

etc., instead of "on which''; can't be taken; its subobjects "belong to''

it rather than "are part of'' it; messages don't assume it can be

"touched'' or "squeezed'' as an ordinary object can; the actions <TT>Attack</TT>,

<TT>ThrowAt</TT> are diverted to <TT>life</TT> rather than rejected as being 'futile

violence'.

<DT><TT>clothing</TT><DD>

"Can be worn.''

<DT><TT>concealed</TT><DD>

"Concealed from view but present.''

The player object has this; an object which was the player until

<TT>ChangePlayer</TT> happened loses this property; a <TT>concealed</TT> <TT>door</TT> can't be

entered; does not appear in room descriptions.

<DT><TT>container</TT><DD>

Affects scope and light; object lists

recurse through it if <TT>open</TT> (or <TT>transparent</TT>); may be described as closed,

open, locked, empty; a possession will give it a <TT>LetGo</TT> action if the

player tries to remove it, or a <TT>Receive</TT> if something is put in; things can

be taken or removed from it, or inserted into it, but only if it is <TT>open</TT>;

likewise for "transfer'' and "empty''; room descriptions describe using

<TT>when_open</TT> or <TT>when_closed</TT> if given; if there is no defined <TT>description</TT>,

an <TT>Examine</TT> causes the contents to be searched (i.e. written out) rather

than a message "You see nothing special about...''; <TT>Search</TT> only reveals

the contents of <TT>container</TT>s, otherwise saying "You find nothing''.

"Is a door or bridge.'' Room descriptions

describe using <TT>when_open</TT> or <TT>when_closed</TT> if given; and an <TT>Enter</TT>

action becomes a <TT>Go</TT> action. If a <TT>Go</TT> has to go through this

object, then: if <TT>concealed</TT>, the player "can't go that way'';

if not <TT>open</TT>, then the player is told either that this cannot

be ascended or descended (if the player tried "up'' or

"down''), or that it is in the way (otherwise);

but if neither, then its <TT>door_to</TT> property is consulted to

see where it leads; finally, if this is zero, then it is said

to "lead nowhere'' and otherwise the player actually moves to

the location.

<DT><TT>edible</TT><DD>

"Can be eaten'' (and thus removed from game).

<DT><TT>enterable</TT><DD>

Affects scope and light; only an <TT>enterable</TT> on the floor can be

entered. If an <TT>enterable</TT> is also a <TT>container</TT> then it can

only be entered or exited if it is <TT>open</TT>.

<DT><TT>female</TT><DD>

This object has a feminine name. In games written in English,

this makes her a female person, though in other languages it might

be inanimate. The parser uses this information when considering

pronouns like "her''. (In English, anything <TT>animate</TT> is assumed

to be male unless <TT>female</TT> or <TT>neuter</TT> is set.)

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<DT><TT>general</TT><DD>

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A general-purpose attribute, defined by

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the library but never looked at or altered by it. This is left

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free to mean something different for each object: often used by

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programmers for something like "the puzzle for this object has been

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solved''.

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<DT><TT>light</TT><DD>

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"Is giving off light.'' (See <A HREF="section17.html">Section 17</A>.) Also: the parser understands

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"lit'', "lighted'', "unlit'' using this; inventories will

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say "(providing light)'' of it, and so will room descriptions if the

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current <TT>location</TT> is ordinarily dark; it will never be automatically

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put away into the player's <TT>SACK_OBJECT</TT>, as it might plausibly be

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inflammable or the main light source.

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<DT><TT>lockable</TT><DD>

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Can be locked or unlocked by a player

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holding its key object, which is given by the property <TT>with_key</TT>;

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if a <TT>container</TT> and also <TT>locked</TT>, may be called "locked'' in

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inventories.

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<DT><TT>locked</TT><DD>

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Can't be opened. If a <TT>container</TT>

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and also <TT>lockable</TT>, may be called "locked'' in inventories.

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This object has a masculine name. In games written in English,

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this makes him a male person, though in other languages it might

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be inanimate. The parser uses this information when considering

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pronouns like "him''. (In English, anything <TT>animate</TT> is assumed

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to be male unless <TT>female</TT> or <TT>neuter</TT> is set.)

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<DT><TT>moved</TT><DD>

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"Has been or is being held by the player.'' Objects

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(immediately) owned by the player after <TT>Initialise</TT> has run are given

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it; at the end of each turn, if an item is newly held by the player

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and is <TT>scored</TT>, it is given <TT>moved</TT> and <TT>OBJECT_SCORE</TT> points are

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awarded; an object's <TT>initial</TT> message only appears in room

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descriptions if it is un<TT>moved</TT>.

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<DT><TT>neuter</TT><DD>

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This object's name is neither masculine nor feminine. (In English,

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anything without <TT>animate</TT> is assumed neuter, because only people and

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higher animals have gender. Anything <TT>animate</TT> is assumed male

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unless <TT>female</TT> or <TT>neuter</TT> is set. A robot, for instance, might be

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an <TT>animate</TT> object worth making <TT>neuter</TT>.)

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"Switched on.'' A <TT>switchable</TT> object with this

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is described by <TT>with_on</TT> in room descriptions; it will be called

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"switched on'' by <TT>Examine</TT>.

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"Open door or container.'' Affects scope and light; lists (such as

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inventories) recurse through an <TT>open</TT> <TT>container</TT>; if a <TT>container</TT>, called

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"open'' by some descriptions; things can be taken or removed from an <TT>open</TT>

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<TT>container</TT>; similarly inserted, transferred or emptied. A <TT>container</TT> can

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only be entered or exited if it is both <TT>enterable</TT> and <TT>open</TT>. An <TT>open</TT>

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<TT>door</TT> can be entered. Described by <TT>when_open</TT> in room descriptions.

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<DT><TT>openable</TT><DD>

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Can be opened or closed, unless <TT>locked</TT>.

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<DT><TT>pluralname</TT><DD>

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This single object's name is in the plural. For instance, an

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object called "seedless grapes'' should have <TT>pluralname</TT> set.

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The library will then use the pronoun "them'' and the indefinite

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article "some'' automatically.

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<DT><TT>proper</TT><DD>

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Its short name is a proper noun, and never preceded

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by "the'' or "The''. The player's object must have this (so something

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changed into will be given it).

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<DT><TT>scenery</TT><DD>

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Not listed by the library in room descriptions; "not portable'' to be

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taken; "you are unable to'' pull, push, or turn it.

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<DT><TT>scored</TT><DD>

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The player gets <TT>OBJECT_SCORE</TT> points for picking

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it up for the first time; or, if a room, <TT>ROOM_SCORE</TT> points for visiting

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it for the first time.

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<DT><TT>static</TT><DD>

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"Fixed in place'' if player tries to take, remove,

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pull, push or turn.

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<DT><TT>supporter</TT><DD>

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"Things can be put on top of it.'' Affects scope and light;

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object lists recurse through it; a possession will give it a

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<TT>LetGo</TT> action if the player tries to remove it, or a <TT>Receive</TT>

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if something is put in; things can be taken or removed from it,

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or put on it; likewise for transfers; a player inside it is said

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to be "on'' rather than "in'' it; room descriptions list

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its contents in separate paragraphs if it is itself listed.

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<DT><TT>switchable</TT><DD>

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Can be switched on or off; listed

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as such by <TT>Examine</TT>; described using <TT>when_on</TT> or <TT>when_off</TT>

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in room descriptions.

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<DT><TT>talkable</TT><DD>

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Player can talk to this object in

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"thing, do this'' style. This is useful for microphones and

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the like, when <TT>animate</TT> is inappropriate.

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<DT><TT>transparent</TT><DD>

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"Contents are visible.'' Affects scope and light;

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a <TT>transparent</TT> container is treated as if it were <TT>open</TT> for

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printing of contents.

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<DT><TT>visited</TT><DD>

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"Has been or is being visited by the player.''

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Given to a room immediately after a <TT>Look</TT> first

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happens there: if this room is <TT>scored</TT> then <TT>ROOM_SCORE</TT> points

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are awarded. Affects whether room descriptions are abbreviated

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or not.

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<DT><TT>workflag</TT><DD>

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Temporary flag used by Inform internals,

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also available to outside routines; can be used to select items

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for some lists printed by <TT>WriteListFrom</TT>.

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"Item of clothing being worn.'' Should

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only be an object being immediately carried by player.

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Affects inventories; doesn't count towards the limit of

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<TT>MAX_CARRIED</TT>; won't be automatically put away into the

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<TT>SACK_OBJECT</TT>; a <TT>Drop</TT> action will cause a <TT>Disrobe</TT> action first;

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so will <TT>PutOn</TT> or <TT>Insert</TT>.

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Note that very few attributes sensibly apply to rooms: only really

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<TT>light</TT>, <TT>scored</TT> and <TT>visited</TT>, together with <TT>general</TT> if you

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choose to use it. Note also that an object cannot be both a

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<TT>container</TT> and a <TT>supporter</TT>; and that the old attribute <TT>autosearch</TT>,

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which was in earlier releases, has been withdrawn as obsolete.

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</TABLE>

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<HR><A HREF="contents.html">Contents</A> / <A HREF="sectionA4.html">Back</A> / <A HREF="sectionA6.html">Forward</A>

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<A HREF="chapter1.html">Chapter I</A> / <A HREF="chapter2.html">Chapter II</A> / <A HREF="chapter3.html">Chapter III</A> / <A HREF="chapter4.html">Chapter IV</A> / <A HREF="chapter5.html">Chapter V</A> / <A HREF="chapter6.html">Chapter VI</A> / <A HREF="chapterA.html">Appendix</A><HR>Mechanically translated to HTML from third edition as revised 16 May 1997. Copyright © Graham Nelson 1993, 1994, 1995, 1996, 1997: all rights reserved.</BODY></HTML>

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