SYNTAX OF THE .WRLD FILE FOR WANDER

The file contains all the location-specific information to describe a particular "world".

The file consists of a series of entries separated by blank lines, each describing one location in a particular state or in all states.

The description of a location for a particular state consists of a location number followed by a period and a state number, (state | numbers start at 0), an optional short description, an optional long description, and a series of actions possible in that state of the location.

The description of a location for all states consists of a location number with no state number, an optional short description, an optional long description, and a series of actions possible in all states of the location.

LOCATION NUMBER & SHORT-DESCRIPTION

The format of the location number & short-description is:
(a sequence of spaces or tabs is represented by <SEP> here)

#lnumber <SEP> short-description

or

#lnumber.snumber <SEP> short-description

Lnumber, (location number), is a decimal number in the range 1 to | ???, (this limit, commonly 256 or 512, is defined by MAXLOCS in the file "wanddef.h"), preceded by ’#’.

Snumber, (state number), is a decimal number in the range 0 to 127.

If the first form is used, (#lnumber), the follwing lines describe the "base state", i.e. characteristics shared by ALL states of the given location. If the second form is used, (#lnumber.snumber), the following lines are only active when the specified state is active.

Short-description is a one-line description used to identify the location after its full description has already been given.

Wander initially places the user in state 0 of location 1 unless | the user specifies differently by setting the variable "CUR_LOC" in | the file, (see ".misc" documentation). The assignment of numbers | to locations is entirely up to the user and they need not be in any particular order in the file.

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LONG-DESCRIPTION

Long-description may be up to 1024 characters in length, and may contain any number of lines, but may not contain a line starting with a <SEP>, (i.e. neither spaces nor tabs), or ’#’ unless the whole thing is in quotes because the first such line indicates the beginning of the next section, (actions or a new location/state). It’s common to enclose the entire long description in quotes in which case lines may begin with a <SEP> or ’#’. If the long description is not quoted but you need spaces at the beginning of a line a line starting with an escaped space, "\ ", will work.

ACTIONS

The format of actions is as follows:

<SEP>match<SEP>dest<SEP>contin<SEP>field<SEP>field<SEP> . . . m=text message

All of these fields, with the exception of match, are optional. |

Match is either one or several words, often thought of as verb or verb & object. If it is more than one word the words are separated by escaped spaces or are enclosed in quotes. This word (or words) is matched against the user’s input by a minimal match process which facilitates abbreviation. Match patterns can be combined with logical OR as match | match | . . .
For example,
light\ up|smoke t?cigarettes m="Eeech! These butts taste awful!"
Which is equivalent to:
"light up" t?cigarettes m="Eeech! These butts taste awful!"
smoke t?cigarettes m="Eeech! These butts taste awful!"

The verb "*" is a special case that matches anything typed by the user.

Dest is the number of the location to which the user will be moved if all tests succeed and is optional. A value of 0, (or omission of the dest field), provides no movement while a negative value ends the game (-1 is a verbose exit, -2 is a silent exit like "quit"). A variable value like "%4%" will be replaced by the contents of of the appropriate variable, (variable 4 in this example), evaluated at the time the user types the command.

The optional contin argument is either "..." or ",,,". Either form indicates that even if this action passes all tests and is carried out the search should continue for any further actions that match, thus allowing multiple actions to be triggered by a single command. The ",,," form requires that another match be found for the command to be "satisfied" and the program will complain if none is found, while the "..." form does not; (it is common to use ",,," for actions that are "transparent" or hidden from the user).

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The m=text message argument may contain an arbitrary text message of up to 512 characters. This message is output as the last step | in carrying out the results of an action. "\b", "\n", "\r", and "\t" are interpreted as backspace, return-line-feed, return and tab respectively. The construction "%3%" is replaced by the value of variable 3. The constructions "%INP_W1%", "%INP_W2%", ..., "%INP_W5%", are replaced by the words used in the last input command that were recognized by the parser. The replacement of "\" and "%" symbols is done at output time.

The field arguments contain test/result specifications. There may be up to eight, fields in any action, (this number can be changed | by redefining MAXFIELDS in "wanddef.h"), and there may be several of a single type. The result fields are carried out in left-to-right order.

The possible test fields are:

test field succeeds if

The possible result fields are:

field result

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t+obj Object "obj" is now being carried
t+obj@lval "obj" is now being carried if its in loc lval
c=command "command" replaces the users input command
w=foo "foo.misc" & "foo.wrld" become the new environment
b=lval.sval Set the "been" count for loc lval to sval |
b+lval.sval Add sval to the "been" count for loc lval |
b-lval.sval Sub sval from the "been" count for loc lval |

In the above, "sval" must be in the range 0 to 127, "lval" must be in the range 0 to 255, (or whatever the maximum location is, check | the "~version" command or the definition of MAXLOCS in | "wanddef.h"), and "bval" must be in the range -32768 to 32767, Any of these may be expressions of the form "%sval%" where sval is the number of a variable (in the range 0 to 127). In the %sval% case the value of the variable is substituted at the time of the action. For instance "v=1.%3%" will save the current value of variable 3 in variable 1. The special variables described in the main Wander documentation file may also be used, (CUR_LOC, MAX_CARRY, etc).

The "been to" counter for each location is an 8-bit counter | associated with that location; it is zero until the location has | been seen; after that it is incremented each time a description is | given and then reset to 1 each time a long description is given.

EXAMPLES

A few examples may help: (lines beginning with ":" are comments and describe the line or lines preceding them.)

: short description used for all states of location 12
You are in the Spaceport Bar on Aldebaran III, which is now deserted
except for you and the burly bartender whose eyestalks keep twitching
in your direction. A large sign hangs over the bar.
: long description for all states of location 12
read\ sign t~dictionary m="The sign is in some local dialect."
: if the user has no dictionary and asks to read the sign then this
: message is output and Wander awaits further input. (Note no dest)
read m="The sign says \"All humans MUST show papers before leaving!\""
: if the user asks to read the sign and gets this far he/she must have
: the dictionary; the message is output and Wander awaits further input.
: note the escaped quotes.
buy\ drink v>6.4 v-6.5 m="It cost 5 credits but it’s good!"
: if the user types "buy drink" and variable 6 (which, in this case,
: represents how many credits she/he has) is greater than 4 (i.e.
: 5 or more) then the user gets a drink and loses 5 credits. Note
: that if the user types "buy" there will only be a partial match
: and Wander will ask "buy what?" If, on the other hand, the user
: types "buy peanuts" Wander will answer "You can’t buy peanuts here".
buy\ drink m="A drink costs 5 credits and you ain’t got it."
: this catches the paupers
buy o?%INP_W2% m="The %INP_W2%’s not for sale."
buy m="I’m all out of %INP_W2%, buddy."
: if the user asks to buy something else, e.g. drugs, a reasonable
: answer is given, depending on whether it’s there or not.

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#12.0
: Header for state 0 of loc 12. Since no short description or long
: description are provided they default to the all-state ones above.
: the following are state 1 actions
leave -1 m="With an amazingly graceful movement for someone\
his size, the bartender leaps\nover the bar and clubs you to death\
while pointing at the sign!"
: if the user types "leave" or "out" without first showing papers
: the bartender kills him/her and the dest of -1 ends the game.
: Note that the message has escaped line-feeds in it for readability
: which are ignored by Wander. When real line-feeds are needed,
: "\n" is used instead.
show\ papers s=12.1 m="He checks you papers and grunts happily."
: to match this the user must have typed "show papers". Wander
: prints the happy grunting bartender message and the state of
: this location (12) is changed to 1, (it was zero), all further
: input will be interpreted according to the state 1 actions below

#12.1
: because no short description is provided here the all-state one
: (above) is used.
You are in the Spaceport Bar on Aldebaran III, which is now deserted
except for you and the burly bartender who has brought you a drink,
(on the house), after learning that you are a user of UNIX software.
: the long description for state 1 (followed by state 1 actions)
leave 13 m="The bartender wriggles a pseudopod in farewell."
: now it’s okay to leave. The user is moved to location 13.
ask o+map m=\
"The barkeep feigns ignorance, but leaves something lying on the bar."
: if the user types anything beginning with "ask", the bartender
: plays innocent but the "o+map" leaves the map to be taken.
read map o?map m="It’s too dark in here to decipher it."
: we expect the user to try this, but we want to put it off a little.

* t?map ... m=\
"The map in your hand glows briefly and you read the words:
Find Ignarp in Crystal City and tell him ’Axolotyl’.
Then the map turns into sooty ash."
: If the user has the map, no matter what’s been typed, this one
: is invoked. The long message is output and then Wander contimues
: to try to match the user’s input (because of the "...").
north 14 v>6.15 v-6.127 m="As you step into the alley two\
ruffians bump into you\nand make profuse apologies."
: if the user enters the alley and has more than 15 units of credit the
: ruffians pick his pocket and the "v-6.127" leaves him with 0 credits.
north 14
: this matches "north" when the previous one doesn’t

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east 20
west 18
: simple movement to other locations

These few examples can’t demonstrate all the possibilities, but they should provide a beginning understanding of the mechanisms involved.

One last example -- Let’s assume that, rather than express money simply as Cosmic Credits, we’d like to also have a Credit Card which you must use to establish your identity. We’d like the ruffians to lift the card itself and then use up 20 credits in the bar... In location 13 the ruffian line would be replaced by this one:

north v>6.30 t?card o+card@12 v-6.20 s+12.2 m=\
"As you step into the alley two ruffians bump into you & make profuse apologies
(better check your pockets)."
: if you have more than 30 credits (v>6.30)
: and you’re carrying the credit card (t?card)
: the card is moved to loc 12 (the Bar), and left there (o+card@12),
: twenty credits are spent from your account (v-6.20),
: the state of the bar is increased by 2, (s+12.2)
: loc/state 12.2 will contain two ruffians and an unfriendly barkeep,
: loc/state 13.2 will contain two ruffians and a friendly barkeep,
: finally, the message is printed.

After this line has been executed the user can go back to the bar and retrieve his credit card from the now-drunk ruffians. You might want to allow pocket checking with something like:

check\ pockets t?watch ... m="You’re carrying a watch."
: if you have a watch mention it and continue
check\ pockets t?ring ... m="You’re carrying a ring."
: if you have a ring mention it and continue
check\ pockets t~watch t~ring ... m="You’re empty-pocketed."
: if none of the expected items are there mention that and continue
: (note that the program has a similar built-in response for "inventory"
check\ pockets v=6.1 m="Your account now holds one measly credit."
: being careful about singular/plural
check\ pockets m="Your account now holds %6% credits."
: if it gets here then plural is safe

BUGS

You see, I found the last bug; but when I killed it ... Well, the funeral procession reached three times around the computer room.

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SEE ALSO

misc.doc, wander.doc

Copyright (c) by Peter Langston, N.Y.C. All rights reserved.

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