The Macintosh Bible Guide to Games/GameGuideCd.bin/Shareware/Miscellaneous/tads22 folder/TADSVER.MAC

Text File | 1994-09-24 | 94KB | 2,042 lines

This file contains a list of changes that have been made to TADS
since the version 2.1.0 release.  Most of the changes are fixes to
bugs, so they don't change the documented behavior, but a few, as
explained below, add new functionality to TADS.  Releases are
listed with the most recent release first; each release incorporates
all new features and bug fixes of each prior release unless
otherwise stated.

Note:  changes from version 2.0 up to 2.1.0 are not included in
this file in order to keep its size under control.  The revisions
from 2.0 through 2.1.0 are available in the file TADSV200.DOS, which
can be found on the High Energy BBS.


2.2.0  ??/??/??  new features, enhancements, bug fixes

  - TADS now has support for reading and writing files.  This new
    feature is intended to let you save information independently
    of the game-saving mechanism, which allows you to transfer
    information between sessions of a game, or even between two
    different games.  The TADS file operations are not designed
    as general-purpose file system operations; in particular,
    these new functions don't have any provisions for creating or
    reading formatted files, or for exchanging information with
    programs other than TADS games.

    To open a file, use the fopen() function.  This function takes
    two arguments:  a single-quoted string giving the name of the
    file to open, using local file system conventions, and a "mode."
    (For  maximum portability, you should avoid using volume names,
    directories, folders, or other path information in filenames.)
    The mode argument is one of these single-quoted string values:

        r    open file for reading; file must already exist
        r+   open file for reading and writing; the file is
             created if it doesn't already exist
        w    create a new file for writing; the file is deleted
             if it already exists
        w+   create a new file for reading and writing; the file
             is deleted if it already exists

    The return value of fopen() is a "file handle"; this is simply
    a number that you you to perform subsequent operations on the
    file.   For example, this opens a new file called TEST.OUT for
    writing:

        fnum := fopen('test.out', 'w');

    To close an open file, use fclose():

        fclose(fnum);

    Note that the TADS runtime allows only a limited number of
    files (currently 10) to be open simultaneously, so you should
    close a file when you're done with it.

    To write to a file, use fwrite().  This function takes a file
    handle, and a value to write; the value can be a string, a number,
    or true.  The value can't be nil (this is because the fread() function
    returns nil to indicate failure; if you could write nil to a file,
    there would be no way to distinguish reading a valid nil from an
    error condition).  fwrite() stores the value, along with information
    on its type.

    The fwrite() function returns nil on success, true on failure.  If
    the function returns true, it usually means that the disk is full.

       if (fwrite(fnum, 'string value!')
           or fwrite(fnum, 123))
           "Error writing file!";

    If the file is open for reading, you can read from the file with
    the fread() function.  This function takes a file handle, and it
    returns a value it reads from the file.  The value returned is
    of the same type as the value originally written at this position
    in the file with fwrite().  If this function returns nil, it
    indicates that an error occurred; this usually means that no more
    information is in the file (you've read past the end of the file).

       res := fread(fnum);
       say(res);

    You can get the current byte position in the file with the ftell()
    function:

       "The current seek position is << ftell(fnum) >>. ";

    The ftell() function returns a number giving the byte position
    that will be read or written by the next file operation.

    You can set the file position with fseek() and fseekeof().  The
    fseek() function moves the file position to a particular byte
    position, relative to the beginning of the file.  For example,
    this seeks to the very beginning of a file:

       fseek(fnum, 0);

    The fseekeof() function positions the file at its end:

       fseekeof(fnum);

    Note that you must be careful with fseek().  You should only seek
    to positions that you obtained with the ftell() function; other
    positions may be in the middle of a string or a number in the
    file, so seeking to an arbitrary location and writing could
    render the file unusable by partially overwriting existing data.


  - TADS now allows you to create and delete objects dynamically
    at run-time.  This is done through two new operators:  "new"
    and "delete".

    To create a new object, use this syntax:

        x := new bookItem;

    This dynamically creates a new object whose superclass is bookItem.
    When this statement is executed, the runtime creates a new object,
    assigns its superclass to be bookItem, and executes the "construct"
    method in the new object; this method can perform any creation-time
    setup that's desired.  The default thing.construct in adv.t simply
    moves the new object into its location -- this is necessary so that
    the "contents" list of the location is updated to include the new
    object.

    A new object inherits all of the vocabulary of its superclass.

    To destroy an object you have created, use this syntax:

        delete x;

    This first calls the "destruct" method of the object to notify it
    that it is about to be deleted, then destroys the object.  Further
    references to the object are illegal, since its memory has been
    released (and thus may be given to another object).  The default
    thing.destruct in adv.t moves the object into nil, which removes it
    from its container's "contents" list -- this is necessary so that
    the reference to the object in that list is removed.

    Only objects created with "new" can be destroyed with "delete".
    Objects that are defined statically in your game's source file
    cannot be deleted at run-time.

    Object creation and deletion works correctly with the UNDO
    mechanism.  If the player uses UNDO after a move that created an
    object, the object will be destroyed; likewise, if a player uses
    UNDO after a turn that deletes an object, the object will be
    re-created with the same property values it had prior to deletion.
    Similarly, dynamically-created objects are preserved across SAVE
    and RESTORE operations.

    Note that TADS does not perform any garbage collection on
    dynamically-created objects.  The system is not capable of
    determining whether an object is accessible or not.  Hence, if
    you lose track of any objects you create with "new", they will
    remain in memory forever -- they will even be saved along with
    saved games and restored when the games are restored.  You must
    be careful to keep track of all objects you create to avoid
    filling all available memory (and the swap file) with unreachable
    objects.

  - It is now possible to dynamically add to and delete from the
    vocabulary words of an object.  You can also get the vocabulary
    words of an object at run-time.

    To add to an object's vocabulary, use the new "addword" built-in
    function.  This function takes three arguments:  an object, a
    vocabulary property pointer, and a word to add.  For example,
    to add 'red' as an adjective to the object myBook, you would
    do this:

        addword(myBook, &adjective, 'red');

    To delete the same word, you would write a similar call to the
    new built-in function "delword":

        delword(myBook, &adjective, 'red');

    You can add to and delete from the words of any object, including
    both static objects (explicitly defined in your source code) and
    dynamically-created objects (created with the "new" operator).

    Changes made by addword and delword are tracked correctly by the
    UNDO mechanism, and are saved and restored along with saved games.

    To get the words belonging to an object, use the new "getwords"
    built-in function.  This function takes two arguments:  an object,
    and a property pointer; it returns a list of (single-quoted)
    strings, which are the vocabulary words for the object.  For
    example, assume we define myBook as follows:

        myBook:  item
            sdesc = "small red book"
            adjective = 'small' 'red' 'tiny'
            noun = 'book'
            location = room2
        ;

    Also assume we haven't made any calls to addword() or delword() for
    myBook.  In this case,

        getwords(myBook, &adjective)

    would return this list:

        ['small' 'red' 'tiny']

    Note that the order of the words in the list is not predictable,
    so you shouldn't expect the words to be in the same order as they
    were when you defined them in the source file, or in the same
    order as they were added with addword().

  - We've added a new function that lets you get information on a verb.
    The new function is verbinfo().  This function lets you get the
    verification and action properties for a verb.  The new function
    takes one or two arguments:  the first is the deepverb object whose
    information you want to retrieve; the optional second argument is
    a preposition object.  If you call verbinfo() with only the verb
    argument, it returns the verification and action properties that
    are defined with the doAction definition for the verb.  If you
    also include the preposition argument, it returns the properties
    that are defined with the ioAction definition for that preposition.

    The value returned by this function is a list.  If you call verbinfo()
    with only the deepverb argument, the list has two elements:

      [1]   direct object verification property pointer (verDoXxxx)
      [2]   direct object action property pointer (doXxxx)

    If you call verbinfo() with both the verb and preposition arguments,
    the return value is a list with four elements:

      [1]   direct object verification property pointer (verDoXxxx)
      [2]   indirect object verification property pointer (verIoXxxx)
      [3]   indirect object action property pointer (ioXxxx)
      [4]   true if ioAction has [disambigDobjFirst] flag, nil otherwise

    In either case, if no matching doAction or ioAction definition
    exists for the verb, this function returns nil.

    Note that it is possible that additional flags (similar to
    disambigDobjFirst) may be added in the future; the returned list
    may be expanded to include information on any such added flags.
    So, for compatibility with future versions, we recommend that you
    don't write conditional code based on the length of the list.
    The lists will never shrink, but they may expand.

    For the removeVerb object defined in adv.t, you would get these
    results:

      verbinfo(removeVerb)
        = [&verDoUnwear &doUnwear]

      verbinfo(removeVerb, fromPrep)
        = [&verDoRemoveFrom &verIoRemoveFrom &ioRemoveFrom nil]

  - The ability to create new objects at run-time leads to some
    interesting problems involving indistinguishable objects.  Although
    you should generally use addword (see below) to make your newly-created
    objects distinguishable from one another, this will not always be
    desirable; for example, if you create new gold pieces that serve
    as currency, you will probably not want them to be uniquely named.

    To support indistinguishable objects, especially those created
    dynamically at run-time, the system now has a property that you
    can set to indicate to the parser that an object does not need to
    be distinguished from others of the same class.  The new property
    is "isEquivalent".  When isEquivalent returns true for an object,
    all other objects with the same immediate superclass are considered
    interchangeable by the parser.  When a player uses one of these
    objects in a command, the parser will simply pick one arbitrarily
    and use it, without asking the player which one.

    If a player uses a noun that is ambiguous with multiple equivalent
    items and one or more other items, the parser will need to
    disambiguate the objects as usual.  In such cases, the parser's
    question will list the distinguishable items only once.  For
    example, assume we have five gold coins that are all equivalent
    (in other words, they all have isEquivalent set to true, and they
    all are immediate subclasses of the same class).  Assume further
    that a silver coin and a bronze coin are also present in the room.

       Treasure Room
           You see a bronze coin, five gold coins, and a silver
       coin here.

       >get coin
       Which coin do you mean, the bronze coin, a gold coin, or
       the silver coin?

    Note that the objects which appear only once are listed with "the"
    (using the thedesc property), while the indistinguishable objects
    are listed only once, with "a" (using the adesc property).

  - The new property pluraldesc has been added to thing in adv.t.
    The definition in thing simply adds an "s" to the end of the
    sdesc property.  This new property is used by listcont(obj)
    when multiple equivalent objects are present in a list; see the
    information on the changes to listcont(obj) for details.

  - The adv.t functions listcont(obj) and itemcnt(list) have been
    changed to support indistinguishable objects.  To support this
    new functionality, the new functions isIndistinguishable(obj1, obj2)
    and sayPrefixCount(cnt), and the new property pluraldesc, have
    been added to adv.t.

    isIndistinguishable(obj1, obj2) returns true if the two objects
    obj1 and obj2 are equivalent for the purposes of listing.  The
    two objects are considered equivalent if both have the same
    first superclass (the return value of the new built-in function
    firstsc(obj)), either they are both being worn or neither is
    worn, and either both are lit lightsources or neither is.  This
    function doesn't test the isEquivalent property of either object,
    since it's assumed that it will only be called if an object has
    already been found whose isEquivalent property is set.

    sayPrefixCount(cnt) displays a number.  If the parameter cnt is
    a small number (from one to twenty), the spelled-out number will
    be displayed (for example, "five" will displayed if cnt = 5).  If
    the count is larger, the number will be displayed as digits ("35"
    will be displayed if cnt = 35).  This function is used by
    listcont(obj) to show the number of equivalent items when more
    than one equivalent item is being listed.

    itemcnt(list) now returns the number of distinguishable items in
    the list that are to be listed.  For each item in the list whose
    isEquivalent property is true, itemcnt(list) checks each other
    item in the list, and counts each set of equivalent items only once.
    Hence, if a list consists entirely of equivalent items, itemcnt(list)
    will return at most 1 (it will return 0 if none of the items are
    listable).

    listcont(obj) will list each set of indistinguishable items in the
    contents list only once, and will show the number of each such item.
    To display the number, the new function sayPrefixCount(cnt) is
    used.  For example, if a room contains a silver coin, a bronze coin,
    and five gold coins (all with the isListed property set to true),
    listcont(room) will display this:

       a silver coin, a bronze coin, and five gold coins

  - A new built-in function has been added to make it possible to
    implement the functionality of the new listcont method.  The new
    function, firstsc(obj), returns the first immediate superclass of
    the given object (or nil if the object has no superclass).  This
    function, along with the isEquivalent property, can be used to
    determine if two objects should be considered indistinguishable.

  - A new special word has been added:  ANY, which is equivalent to
    EITHER.  These words are at the end of the original specialWords
    list; for compatibility with past versions, a specialWords list
    that omits this position is still legal, and indicates that the
    default ('any' = 'either') should be used for this slot.

    This special word slot is used by the parser during disambiguation.
    Whenever the parser asks the player to choose an object from a list
    of ambiguous objects, it will accept ANY:

        >take coin
        Which coin do you mean, the silver coin, the bronze coin, or
        the gold coin?

        >any
        silver coin:  Taken.

    When ANY is used in these cases, the parser will simply pick one
    of the objects arbitrarily.  Note that it displays the chosen
    object in the same manner as it would if multiple objects were
    being used.

    In addition, the parser will accept noun phrases that start with
    ANY to indicate that any object matching the given noun phrase is
    acceptable; the parser will choose one of the objects arbitrarily
    in these cases.  For example:

        >take any coin
        silver coin:  Taken.

        >look at any of the coins
        bronze coin:  It's a valuable 1964 Tadsmid, worth over
        .0004 cents on today's scrap bronze market.

    The player can also specify the number of items to take.  When
    a number of items is specified, it must be applied to a plural
    noun phrase, and it means the same thing as "any," except that
    the parser (arbitrarily) chooses the given number of items rather
    than just one.  For example:

    >look at 3 coins
    >look at any 3 coins
    >look at 3 of the coins
    >look at any 3 of the coins

    As a special case, a count of "1" can be used with a singular
    noun phrase.  It means the same thing as "any."

        >look at 1 coin

  - A new convenience feature, similar to doSynonym and ioSynonym but
    somewhat easier to use, has been added.  You can now specify that
    a method in one object should instead be sent to another object.
    An example:

        desk: fixeditem
            noun = 'desk'
            sdesc = "desk"
            location = office
            doOpen -> deskDrawer
            doClose -> deskDrawer
        ;

    This specifies that doOpen, verDoOpen, doClose, and verDoClose
    calls should be sent to the deskDrawer object when received by
    the desk.  Note that this should only be used for standard verb
    handler methods, because it redirects both the method indicated
    and its verXoVerb equivalent.

  - The parser calls a new method, multisdesc, when displaying the
    name of an object that's part of a list of objects.  Previously,
    the parser simply used sdesc in these cases.  The default adv.t
    definition of thing.multisdesc simply calls the object's sdesc.
    This new method is intended to allow you greater control over
    the display in situations like this:

      >get all
      book:  Taken.
      rug:  That's much too heavy to carry.

    The object names listed before the colons are now displayed
    with multisdesc.

    For compatibility with old games, if an object being listed does
    not define or inherit a multisdesc property, its sdesc is used
    instead.  This ensures that games compiled with previous versions
    of adv.t will continue working properly.

  - A new user-defined function that the parser calls has been added.
    This new function is called preparseCmd(), and is similar to
    preparse().  Whereas preparse() is called once for an entire
    command line, and is called with the original, unfiltered text
    of the player's command line, preparseCmd() is called separately
    for each command on a command line if more then one command is
    entered.  Furthermore, preparseCmd() is called after the command
    has been "tokenized" (broken into individual words).  Whereas the
    argument to preparse() is a string with the entire command line,
    the argument to preparseCmd() is a list, each entry of which is
    a (single-quoted) string giving an individual word.  Using the new
    function, you can exert much greater control over how a command
    is parsed, including rewriting a command entirely.

    preparseCmd() is called immediately before Me.roomCheck() is called
    for the command.  This call is made prior to any disambiguation or
    object defaulting.

    If preparseCmd() returns nil, the command is abandoned (but no
    error message is displayed), and no fuses or daemons are run.  If
    the function returns true, the command proceeds as normal.  Any
    remaining commands on the same line are executed regardless of the
    return value from preparseCmd().  (If you need to cancel the entire
    rest of the command line, one approach would be to set a property
    in the global object to indicate to preparseCmd() that all commands
    are to be ignored; preparseCmd() would always check this property
    before doing anything else, and return nil if it were set.  You
    could clear this property in preparse() so that commands always
    start off enabled.)

    In addition, preparseCmd() can return a list of (single-quoted)
    strings, in which case the parser starts over parsing the list
    instead of the original command.  The list is limited to a maximum
    of 128 characters, with one additional character of overhead per
    word -- in other words, you can't make the new command longer
    than the original command, which is limited to the same maximum
    when entered by the player in the first place.  However, you can
    otherwise rewrite the command entirely.  If you want to include
    any special words in the new command, use the conventions described
    below (for example, if you want to include 'and' in the new command,
    use ',' instead).  After the new command inserted by preparseCmd()
    has been processed, the parser will resume processing any remaining
    commands on the player's original command line.

    The new command list returned by preparseCmd() can contain multiple
    commands.  Simply separate the commands with commas (',') in your
    list.

    If preparseCmd() returns a list, preparseCmd() will be invoked on
    the new command.  However, preparseCmd() is not allowed to return
    another new command in these cases -- if it does, the parser will
    assume that preparseCmd() is looping, and will generate an error.

    Several new parseError codes have been added to respond to error
    conditions that can arise from preparseCmd():

        32  Internal game error: preparseCmd returned an invalid list
        33  Internal game error: preparseCmd command too long
        34  Internal gmae error: preparseCmd loop

    The sample implementation of preparseCmd() below simply lists all
    of the words in the current command and displays a newline, then
    allows the command to proceed as usual.

        #pragma C+
        preparseCmd: function(cmd)
    {
        local i, tot;

        for (i = 1, tot = length(cmd) ; i <= tot ; ++i)
            "<<cmd[i]>> ";
        "\n";

            return true;
    }

    Note that the parser performs conversions of the special words.
    These conversions will show up in the list as follows:

        "and"   becomes  ","
        "all"   becomes  "A"
        "but"   becomes  "X"
        "it"    becomes  "I"
        "them"  becomes  "T"
        "him"   becomes  "M"
        "her"   becomes  "R"
        "any"   becomes  "Y"

    Here are some examples using the preparseCmd() function above.
    (The actual response of the commands has been removed -- only the
    text displayed by preparseCmd() is shown.)

        >look at all
        look at A

        >examine him; take everything except the box and the book and go north
        examine M
        take A X the box , the book
        go north

    preparseCmd() is called even for commands that the parser doesn't
    understand.  This allows you to rewrite commands that TADS wouldn't
    normally understand and put them into a format that's acceptable to
    the parser.  For example, the preparseCmd() example below will
    take sentences of the form "tell <actor> to <command>", and convert
    them to the normal TADS syntax, "<actor>, <command>".

        #pragma C+
        preparseCmd: function(cmd)
    {
        local i, tot, to_loc, actor, the_rest;

            tot = length(cmd);

        /* check to see if it starts with "tell" */
        if (tot > 3 && cmd[1] == 'tell')
        {
            /* see if there's a word "to" */
        for (i = 1, tot = length(cmd) ; i <= tot ; ++i)
        {
            if (cmd[i] == 'to')
                to_loc = i;
        }

        /* if there's a "to", convert the command */
        if (to_loc != nil && to_loc > 2)
        {
            /* find the parts before and after the 'to' */
            for (i = 2, actor = [] ; i < to_loc ; ++i)
                actor += cmd[i];
            for (the_rest = [], i = to_loc + 1 ; i <= tot ; ++i)
                the_rest += cmd[i];

            /* convert it to "actor, command" */
            return actor + ',' + the_rest;
        }
        }

            /* otherwise, process the command as normal */
            return true;
        }

    When the parser doesn't know how to handle a sentence, it calls
    preparseCmd with the entire rest of the command (which will include
    everything before the next THEN or period), and processing is the
    same as in any other case.  If preparseCmd() returns nil in this
    case, the command is cancelled as usual without any further
    processing by the parser.  If preparseCmd() returns true when the
    sentence is not recognized by TADS, the parser will display the
    usual message (parseError code 18, "I don't understand that
    sentence").  If preparseCmd() returns a list of strings, the
    command is replaced with the list, and the parser starts over
    processing the new command.

  - Several new parseError codes have been added.

    In order to produce better messages when actors are involved,
    the system now attempts to figure out whether an object in a
    command refers to an actor, and if so, to determine whether the
    actor should be called "him" or "her".  Previously, this
    one-size-fits-all message was generated:

       What do you want to <verb> it <prep>?

    for example:

       >hit bill
       What do you want to hit it with?

    Although it's not always possible to determine which object
    should be used in these cases (because disambiguation will not
    be possible until the indirect object is known), the system will
    make its best guess.  To do so, it looks at all of the objects
    that might be involved, based on the vocabulary.  If the player
    appears to mean multiple objects, " them " will be used -- this
    is message number 144 for parseError:

       >throw ball and bat
       What do you want to throw them at?        <- message 144
                                ------

    If only one object appears to be intended, the parser will try
    to figure out whether the object is male, female, or neuter,
    using the isHim and isHer properties (these properties are not
    new; they have been around since before TADS 2.0).  If all of
    the objects that match a single noun phrase have isHim and
    not isHer, " him " will be used -- this is parseError message
    number 145:

      >hit bill
      What do you want to hit him with?          <- message 145
                             -----

    If they all have isHer and not isHim, " her " will be used
    (message number 146):

      >hit jill
      What do you want to hit her with?          <- message 146
                             -----

    If both are set, the system equivocates with " them ", message
    number 147 (note that this is the same default text as message
    144, but it's distinguished as a separate message number in
    case a game author wants a more suitable word in this case,
    especially in a non-English language):

      >hit hermaphrodite
      What do you want to hit them with?         <- message 147
                             ------

    If not all of the objects involved have isHim and/or isHer
    set, the system uses "it" (message 141) as in previous versions.

    Another change to the processing for this message involves
    actors.  If an actor is specified in the command, the system
    now builds a replacement for message 140.  First, message
    148 is displayed, which has the default text "What do you want ".
    Then, the actor's thedesc is invoked to display the actor's
    name.  Finally, message 149 (default text " to ") is displayed,
    and the rest of the message is built as before.

      >guard, throw ball
      What do you want the guard to throw it at?
      -----------------         ----
         message 148             149

  - The functionality of the parseAskobj function has been extended
    so that you can generate the same sort of message that the parser
    now generates when a missing object is needed for a command directed
    to an actor.  To provide the new functionality, the parser now calls
    a function called parseAskobjActor.  This function is exactly the
    same as parseAskobj, except that it takes the actor as the first
    parameter, the verb as the second parameter, and the preposition
    as an optional third parameter (which is only present when asking
    for an indirect object).

    If your game defines parseAskobjActor, the system ignores parseAskobj
    and calls the new function instead.  If parseAskobjActor is not defined,
    but parseAskobj is defined, the system calls parseAskobj as it did in
    past versions.  If neither function is defined, the system generates
    the message itself as described above.  You should use parseAskobjActor
    rather than parseAskobj for new games, since it gives you more
    information.

    Here's an example of parseAskobjActor, which generates roughly the
    same message as the system would (but it doesn't do any of the checking
    of isHim and isHer to determine which pronoun to use -- this function
    simply uses "it").

    parseAskobjActor: function(a, v, ...)
    {
        if (argcount == 3)
        {
            "What do you want ";
                if (a <> Me) a.thedesc;
        " to <<v.sdesc>> it <<getarg(3).sdesc>>?";
        }
        else
        {
        "What do you want ";
            if (a <> Me) a.thedesc;
        " to <<v.sdesc>>?";
        }
    }

  - The parser has been changed slightly to allow a command to specify
    an actor in any command within a single line containing multiple
    commands.  Previously, if an actor was to be specified, the actor
    had to be specified at the very beginning of the command.  This
    restriction has been removed, which allows commands like this:

      >joe, north.  bob, south.  bill, east, take book, west.

    Note that, as in past versions, once an actor is specified, the
    actor remains in effect for subsequent commands.  Since you could
    only specify one actor for an entire command line in past versions,
    this meant that the actor was used for every command on the line;
    with this new version, an actor remains in effect until another
    actor is specified.  So, in the command above, "north" is directed
    to Joe, "south" is directed to Bob, and "east, take book, west"
    is directed to Bill.

  - The maximum number of notifiers has been increased to 200.  The
    maximum number of daemons and fuses has been increased to 100 each.

  - The maximum number of ambiguous words matching a particular
    vocabulary word has been increased to 200.  This should relieve
    problems that some people have reported with the error message
    "The word 'foo' refers to too many objects".

  - The compiler now supports most of the remaining C operators:

        a % b      - returns the remainder of dividing a by b
        a %= b     - sets a to a % b
        a != b     - equivalent to a <> b
        !a         - equivalent to (not a)
        a & b      - bitwise AND
        a &= b     - sets a to the bitwise AND of a and b
        a | b      - bitwise OR
        a |= b     - sets a to the bitwise OR of a and b
        a && b     - equivalent to (a and b)
        a || b     - equivalent to (a or b)
        a ^ b      - bitwise XOR of a and b
        a ^= b     - sets a to the bitwise XOR of a and b
        ~a         - bitwise negation of a
        a << b     - a shifted left by b bits
        a <<= b    - shifts a left by b bits
        a >> b     - a shifted right by b bits
        a >>= b    - shifts a right by b bits

    Note a slight complication involving the >> operator:  you can't
    use this operator from within an embedded string expression, because
    it would be confused by the parser for the end of the expression.
    It doesn't help to use parentheses, since the embedded string
    processing is essentially a textual substitution mechanism which
    happens without knowledge of the expression context (and is thus
    unaware of parenthesization).  For example, this would be illegal:

       myprop = "x divided by 128 is << (x >> 7) >>!"     // wrong

    You would have to code this instead as:

       myprop = { "x divided by 128 is "; x >> 7; "!"; }  // right

    Another slight complication arises from the use of the & operator
    in lists.  Since TADS allows list elements to appear without any
    separating punctuation (except whitespace), you can have a list
    that looks like this:

       mylist = [&sdesc &adesc &thedesc]

    This construct is still legal, and is still interpreted with the
    "&" operators as unary operators, not bitwise AND operators.
    However, the parser now warns when such a definition is used; see
    the description of the new warning TADS-357 below for details.

  - The compiler will generate a new warning when it detects a unary
    operator within a list that could also be interpreted as a binary
    operator.  For example, in this list,

       list2 = [5 -2 -6 -7]

    the "-" operators could be interpreted either as unary negation
    operators, which would result in a list with four elements (the
    numbers 5, -2, -6, and -7), or as binary subtraction operators,
    which would result in a list with only one element (the number
    -10).  This same problem arises with the operators "+" and "&",
    since these also have a unary and binary interpretation which
    depends on context.

    In these cases, the compiler interprets the operators as unary
    operators, and issues a warning to let you know that the usage
    was ambiguous.  The warning is TADS-357:

      TADS-357: warning: operator '-' intepreted as unary in list

    Note that this is a change from the previous version for the '+'
    and '-' operators.  If your game depends on building lists from
    calculated numeric constants, you will need to change your code;
    we don't expect that any games actually depend on the old behavior.

    If you really do want the operators in these cases interpreted
    as binary operators, use parentheses:

       list2 = [(5 -2 -6 -7)]

    The parentheses tell the compiler that the expression is to be
    interpreted as a single list element.

    If you want the unary interpretation, and you want to suppress
    the warning, use commas between the list elements:

       list2 = [5, -2, -6, -7]

    This doesn't change the interpretation, but it does suppress the
    warning, because it removes the ambiguity:  when the commas are
    present, there is no way the '-' operators could be interpreted
    as binary operators.

    You can suppress this warning using a new check box in the
    compiler's warning level dialog.  Check the box to allow TADS-357
    errors to be displayed.  You may want to suppress this warning when
    compiling code written prior to this version of TADS, since the
    warning is generated in case you wanted the new meaning of the &
    operator.  The check box enabling the warning is checked by
    default; uncheck it to suppress the warning.

  - A new compiler command-line option has been added:  -C, a toggle
    option, which turns on and off C-language operator compilation.
    By default, C operator mode is off (-C-), which makes the compiler
    use the normal TADS operators.  Specifying -C+ turns on C operator
    mode; specifying -C- disables C operator mode.

    When C-language operator mode is in effect, two operators are
    affected:  the assignment operator becomes '=', and the equality
    comparison operator becomes '=='.  With normal TADS operator mode
    in effect, assignment is ':=' and equality is '='.  If you are
    a C programmer, and you're unhappy with the slight variation in
    operator notation between TADS and C, you can use -C+ to make TADS
    behave more like a real language.  Thanks to the #pragma C options
    (see below), C operator mode has no effect on your choice of
    header files -- you can use the same old adv.t and other header
    files unchanged, and still use C-style operators in your code.

  - A new preprocessor command has been added:  #pragma.  This special
    directive can be used to specify certain compiler options from
    within your source code.  Currently, the only #pragma option available
    is the C operator mode option.  Use #pragma C+ to turn on C operator
    mode, and #pragma C- to turn it off.

    The #pragma C+ and #pragma C- settings are local to a particular
    file.  If a file is included by another file, the #pragma C settings
    specified in the included file will be in effect only until the end
    of the included file; the including file's #pragma C settings that
    were in effect before including the other file will be restored at
    the end of the included file.  adv.t and std.t now start with a
    #pragma C- command -- this allows adv.t and std.t to be included
    from a file with C-style operators (and thus a #pragma C+ or
    command-line C operator mode setting).  Since the enclosing file's
    #pragma C option will be restored after the inclusion, files with
    different operator modes can be freely intermixed with #include, as
    long as each included file specifies its desired mode with a
    #pragma C directive.

  - The precedence of the comparison operators has been changed to
    be the same as that used by C.  Previously, all of the comparison
    operators were at the same precedence; starting with this version,
    == and <> (and thus !=) are at the same level of precedence, and
    associate left to right as before, but <, >, <=, and >= are one
    level higher in precedence.  The following type of expression will
    be affected:

          a > 1 <> b > 1

    Previously, this grouped as:

          (((a > 1) <> b) > 1   // obsolete

    This now groups as:

          (a > 1) <> (b > 1)    // current behavior

    This shouldn't affect any existing code, since the old interpretation
    should always have resulted in an error (because a truth value, true
    or nil, can not be compared in magnitude to a number or other type).

  - Limited conditional compilation and preprocessor text substitution
    (#define) support has been added to the compiler.  The following
    preprocessor directives are now available:

      #define symbol value
      #undef symbol
      #ifdef symbol
      #ifndef symbol
      #else
      #endif

    #define is used to assign a value to a preprocessor symbol.  The
    "value" is simply text that will be substituted verbatim for the
    symbol whenever it occurs in your file (other than within quoted
    strings).  For example:

      #define TEST say('hello from TEST!')

      myfunc: function
      {
         TEST;
      }

    The symbol TEST is replaced with its definition, so the function
    myfunc() displays "hello from TEST!" when called.

    Preprocessor symbols defined with #define are in a separate
    namespace from all other symbols in your program.  Unlike a
    standard C preprocessor, no arguments are allowed in #define
    macros.

    #undef deletes a previously #define'd symbol.  You can #undef
    the special symbols defined automatically by the compiler if
    you wish (see below).

    #ifdef tests to see if a preprocessor symbol is defined.  If it
    is, the lines following the #ifdef line, and up to the corresponding
    #else or #endif, are included; otherwise, they are ignored.

    #ifndef is the opposite of #ifdef:  #ifndef tests to see if the
    symbol is NOT defined.  If the symbol is undefined, the lines
    following the #ifndef line up to the corresponding #else or
    #endif are included; otherwise, they are ignored.

    #else indicates that the lines between the #else and #endif are
    to be included if an only if the corresponding #ifdef (or #ifndef)
    failed.  #else is optional.  At most one #else is allowed per
    conditional.

    #endif terminates a conditional block.  Exactly one #endif must appear
    for each conditional (#ifdef or #ifndef).

    You can use #ifdef to compile certain parts of your code
    conditionally.  For example, if you want to include a verb only
    for your debugging version of a game, but you want to remove it
    from the final version, you could do something like this:

      #ifdef __DEBUG
      magicVerb:  deepverb
         verb = 'xyzzy'
         action(actor) =
         {
         }
      ;
      #endif

    Note that __DEBUG is especially handy for this sort of thing,
    because the compiler automatically defines this symbol when
    debugging (-ds) is turned no (see below).

  - The compiler automatically defines several preprocessor symbols.
    These symbols can be used or tested within your code as needed.

    __TADS_VERSION_MAJOR is defined to a number indicating the major
    version number of the compiler (in the present system, 2).

    __TADS_VERSION_MINOR is defined to a number indicating the minor
    version number (in the present system, 2).

    __TADS_SYSTEM is defined to a string (single-quoted) identifying
    the operating system the compiler is running on.  In addition, the
    same identifier contained in the string is defined as a preprocessor
    symbol itself (its value is always 1; it is intended that it will
    be tested with #ifdef, and not otherwise used).  For example, if
    __TADS_SYSTEM is 'MSDOS', the symbol MSDOS will be defined to 1.
    If __TADS_SYSTEM is 'Macintosh', the symbol Macintosh will be
    defined to 1.

    __DEBUG is defined to 1 if debugging is turned on for this
    compilation (with the -ds compiler option).  Otherwise, this symbol
    is not automatically defined.  You can test the existence of __DEBUG
    with #ifdef to conditionally include code only when you are compiling
    for debugging.  This might be useful if you want to include certain
    commands only in the debugging version of your game, and want to
    remove them when you actually deliver the game to players.

    If this set of symbols were entered manually with #define statements,
    the definitions might look like this:

      #define __TADS_VERSION_MAJOR  2
      #define __TADS_VERSION_MINOR  2
      #define __TADS_SYSTEM         'MSDOS'
      #define MSDOS

    __DATE__ is defined as a single-quoted string giving the system date
    when the compilation began, in the format "Jan 01 1980".

    __TIME__ is defined as a single-quoted string giving the system time
    when the compilation began, in a 24-hour format, "13:40:50".

    __FILE__ is defined as a single-quoted string giving the file being
    scanned at the point where the __FILE__ macro is encountered.  Each
    time you use __FILE__, it will have the correct value for that point
    in your source code.

    __LINE__ is defined as a number giving the line number at the point
    where the __LINE__ macro is encountered.  Each time you use __LINE__,
    it will have the correct value for that point in your source code.

  - The compiler has two new options that give you further control
    over preprocessor symbols.  The -D option allows you to define
    a preprocessor symbol from the command line.  For example, to
    define TEST to 5 from the command line, you could do this:

      tc -i/tads/include -DTEST=5 mygame.t

    Note that if you omit the equals sign, the default definition
    of the symbol will be 1:

      tc -i/tads/include -DTEST mygame.t

    This defines TEST to 1.

    The -U option undefines a predefined symbol.  You can use this to
    undefine one of the symbols automatically defined by the compiler.
    You can also use it to undefine a symbol defined in a precompiled
    header, if you're loading one; -U is applied after the precompiled
    header is loaded, so it will undefine symbols loaded from the file.
    For example, to compile for debugging, but leave __DEBUG undefined,
    you could do this:

      tc -ds -U__DEBUG mygame.t

    The -U option is applied after all -D options, so you can also use
    it to undefine a symbol placed earlier on the command line.  This
    may be useful if you are using a configuation file (CONFIG.TC)
    that contains -D options for symbols you sometimes want to undefine.

  - The compiler has a new preprocessor directive, #error, which allows
    you to generate your own error during compilation.  If a #error
    directive is encountered, any text after the #error is displayed
    as a compiler error; an occurrence of #error is counted as an actual
    compilation error, so compilation will fail if #error is encountered.
    For example:

       #ifndef TEST
       # error TEST is not defined!
       #endif

    If the preprocessor symbol TEST is not defined at the point when
    this sequence is encountered, the compiler will display an error:

      mygame.t(181): error TADS-124: TEST is not defined!

  - The runtime has a new debugging feature that may help you track
    down problems with word definitions.  You can make the player
    command parser generate a number of status messages as it analyzes
    a player's command; these messages provide information on how the
    parser is interpreting the words in the command.

    To activate this new debug mode, use the debugTrace function with
    these arguments:

       debugTrace(1, true);

    To turn the debug mode off, call with nil instead of true.  This
    debugTrace function is always available, even when running under
    the normal runtime; the function returns no value when called with
    these arguments.

  - The built-in function incturn() has been extended to allow you
    to run a series of turns all at once.  You can now specify a numeric
    argument to incturn(); the argument gives the number of turns that
    should pass.  An argument of 1 causes incturn() to behave as usual.

    When an argument higher than 1 is given to incturn(), the function
    runs all of the fuses that are set to burn down within the number
    of turns specified, but not after that number of turns.  Note that
    the normal incturn() has never actually executed any fuses, but
    simply burns down all fuses by one more turn.

    For example, if you call incturn(2), the system will first run
    any fuses that are set to burn down after 1 turn, then will shorten
    all remaining fuses by one more turn.

  - A new built-in function, skipturn(), has been added.  This new
    function takes a numeric argument specifying the number of turns
    to skip; it must be at least 1.  skipturn(n) is similar to incturn(n),
    except that it does not run any of the fuses that burn down during
    the 'n' turns -- instead, it simply removes them without running
    them.

  - A new built-in function allows you to force capitalization off --
    this function, nocaps(), is the opposite of caps().  If you call
    caps() then call nocaps(), the next character is lower-case; if
    you call nocaps() then caps(), the next character is capitalized.

    Along with nocaps(), the special sequence \v has been added.  Using
    this sequence in a displayed string is equivalent to calling
    nocaps(); this sequence is analogous to \^, which is equivalent
    to calling caps().

  - The parser is now capable of disambiguating direct objects before
    indirect objects.  By default, everything works as it always has --
    in a two-object command, the indirect object is disambiguated first,
    and then the direct object is disambiguated in the presence of the
    known indirect object.

    It is now possible, however, to specify that the reverse should be
    done.  To do this, you use a new special flags syntax when defining
    your verb:

       tellVerb: deepverb
          verb = 'tell'
          desc = "tell"
          ioAction(aboutPrep) = [disambigDobjFirst] 'TellAbout'
       ;

    The new special flags are placed in square brackets between the
    equals sign and the property template for the verb definition.
    The flags currently accepted are:

       disambigDobjFirst
       disambigIobjFirst

    Note that disambigIobjFirst is provided for completeness only; it
    is never needed, because it is the default setting.

    When the disambigDobjFirst flag is specified, it means that the
    command should have its direct object disambiguated before its
    indirect object.

    When the disambiguation order is reversed, the normal argument
    lists for verDoTellAbout and verIoTellAbout are interchanged.
    For our example, the prototypes for the verifier methods become:

       verDoTellAbout(actor)
       verIoTellAbout(actor, dobj)

    Normally, verIoVerb would not receive the direct object as an
    argument, because the direct object would not be known at the time
    of the verIoVerb call; and verDoVerb would receive the indirect
    object as an argument, because it would be known by the time the
    direct object was being tested.  When the disambiguation order is
    reversed, however, so are the prototypes to these functions.

    The actual action method, ioTellAbout(actor, dobj), remains
    unchanged.  All other methods also remain the same.

    When the direct object is disambiguated first, the player is not
    allowed to use multiple direct objects (or multiple indirect objects)
    in the command.  If the player tries to do so, the new parseError
    message number 28 is displayed:

       >tell bob and bill about gun
       You can't use multiple objects with this command.

  - Note that a .GAM file format change was required to support the
    extra information needed for the disambigDobjFirst flag.  The TADS
    file format is now format "C".  The compiler is still capable of
    producing formats A or B, in case you need to generate .GAM files
    that can be played with versions prior to 2.2; however, if you
    use a format prior to C, you will not be allowed to use the
    disambigDobjFirst flag (or any other similar flags that may be
    added in the future).

  - Two new methods have been added to disambiguate actors.  Previously,
    the system validated and disambiguated an actor by pretending that
    you were attempting to take the actor -- takeVerb.validDo and the
    actor's verDoTake were used to validate and disambiguate the actor,
    when all you wanted to do was speak to him.  This did not always
    produce satisfactory results, and in particular did not allow for
    such situations as talking over a radio to an actor in another room.
    To provide better control over actor validation and disambiguation,
    the system for testing actors has been enhanced.

    First, to validate an actor, the system now uses the method
    validActor in the actor object itself.  This method takes no
    arguments; it returns true if the object is valid as an actor in
    a command, nil otherwise.  This method is called before the verb
    or any of the objects involved in the sentence are known.  Its
    function is not to determine whether the actor wants to receive
    the command, or even if the object can be used as an actor
    (actorAction is the place to do both of these tests), but rather
    simply to determine if the object can be addressed by the player
    at all.  This method should return true if the actor is accessible
    by voice command (or whatever other means you want to provide for
    giving commands) to the player.  The default thing.validActor in
    adv.t returns true if the object is reachable by Me, which provides
    roughly the same behavior as the old takeVerb-based mechanism.

    Second, to disambiguate an actor, the new preferredActor method
    has been added.  This method is called if an actor is ambiguous.
    As with validActor, it doesn't take any arguments, and it returns
    true if the object is "preferred" as an actor, nil otherwise.  If
    exactly one ambiguous object's preferredActor method returns true,
    the parser will use that object as the actor without further
    questioning the player; otherwise, the system will ask the player
    to disambiguate the noun as normal.  In adv.t, movableActor defines
    preferredActor = true.

    An example of how these might be used:

       Sleeping Compartment
          You are in a sleeping compartment on a moving train.
       A pair of bunks is along each wall.
          There is a copper wire here.
          The train conductor is standing in the doorway, asking for
       your ticket.

       >look at conductor
       Which conductor do you mean, the copper wire, or the train
       conductor?

       >copper
       It's a piece of wire, about a foot long.

       >conductor, where is ivan?
       "Your ticket, please," is all the conductor has to say.

    In this sequence, when the command is addressed to "conductor", the
    parser matches both the copper wire and the train conductor.  It
    checks validActor in each of them -- both return true, since both
    are accessible to the player.  (As described above, even though the
    copper wire couldn't possibly be an actor, it is valid as an actor
    at this point -- it's not until its actorAction that we will decide
    that there's no point in talking to it.)

    So, the parser has an ambiguous actor.  The parser tries to
    disambiguate the actor by testing preferredActor in each object.
    The copper wire's preferredActor returns nil; the train conductor's,
    however, returns true, because the conductor is a movableActor
    object.  The parser now has only one object, and thus doesn't
    need to ask the player for further information.

    For compatibility with games compiled with previous versions of
    adv.t, the parser will continue to use the old mechanism (involving
    the takeVerb) if validActor is not defined in your game.  Each time
    an actor is used, the parser checks to see if the first object in
    the list of possible actor objects has a validActor method defined;
    if not, the parser uses the old mechanism.  If you use the new adv.t,
    all objects will at least inherit a validActor method (from thing),
    so testing for the presence of this method in any object lets the
    parser determine if the new mechanism can be used with the game.

  - A new parseError message has been added:  number 27, whose default
    text is "You can't repeat that command."  This message is displayed
    when the player types AGAIN, but the parser can't repeat the command;
    this is the case if one of the objects involved in the command is
    no longer accessible.

  - A new parseError message has been added, related to validActor
    (see above).  This new message, number 31, is used when none of
    the objects matching the vocabulary for an actor in a player's
    command can be used as an actor.  The default text of this message
    is "You can't talk to that."  For example, if there is no object
    matching the vocabulary "guard" whose validActor method returns
    true, but an object named "guard" is visible to the player, the
    message is used:

      Security Room
          You are inside a small cubicle.  A thick, laser-proof
      (as you now know from your ill-fated attempt) glass door
      (closed) is to the north.  Through the door you can see
      a guard standing watch.

      >guard, open door
      You can't talk to that.

    This message is used for actors in place of the standard cantReach
    processing done for direct and indirect objects under these conditions.

  - A new parseError code, number 29, has been added.  The default
    message is "I think you left something out after 'any of'", and
    is used when the player uses "any of" in a sentence, but doesn't
    follow it with anything.

  - Using the same word as both a plural and a noun works much better
    now.  The parser will first attempt to use such a word as a plural;
    if no objects match the plural usage, the parser will try to use
    the word as a noun instead.

  - "of" can now be used as a preposition.  In previous versions of
    the run-time, "of" was exclusively a special word that was embedded
    in noun phrases (such as "pile of paper").  The runtime will still
    allow "of" to be used in noun phrases as before, but it also will
    treat "of" as an ordinary word when, based on the context, it does
    not appear to be part of a noun phrase.

    The parser will still attempt to treat "of" as part of a noun
    phrase whenever it matches an object.  For example, if you have
    an object with nouns matching "pile of paper", then the following
    interpretations will apply:

        accuse bob of murder   ->  dobj = bob, iobj = murder, prep = of
        accuse pile of paper   ->  dobj = pile of paper

    Note that ofPrep, defining "of" as a preposition, has been added
    to adv.t.

  - All of the system verbs that use "abort" have been modified
    slightly in adv.t to make it easier to augment their behavior
    with the 'modify' statement.  All of the processing other than
    the "abort" has been moved out of the doVerb (or action) method
    in each case, and put into a new method.  For example, saveVerb's
    action routine now looks like this:

        action( actor ) =
        {
        self.saveGame(actor);
        abort;
    }

    The new method saveVerb.saveGame(actor) now performs all of the
    processing that the action(actor) method previously performed.

    The benefit of this change is that you can now modify the
    saveGame(actor) method, and inherit the original behavior,
    without having to worry about an "abort" interfering with the
    order of operations.  For example:

        modify restoreVerb
            restoreGame(actor) =
            {
                // restore the game as usual - check for success
                if (inherited.restoreGame(actor))
                {
                    // re-randomize the puzzle
            "The carnival hawker flashes a mischevious
            smile at you.  \"There's no use trying to
            guess the answer,\" he says.  \"I changed
            around the shells while you were busy
            restoring!\"";
            puzzle.answer := rand(100);
                }
            }
        ;


  - The format mask fmtMe has been added.  You can now use %me% in
    messages to refer to the actor.  For basicMe, fmtMe is set to
    the message "me"; for other actors, it is set to the actor's
    thedesc.  In adv.t, thing.ldesc has been changed to use %me%:
    "It looks like an ordinary <<sdesc>> to %me%."  This makes the
    default sentence somewhat more adaptable if you ask another
    actor to describe something:

        >guard, look at the card
        It looks like an ordinary card to the guard.

  - AGAIN, WAIT, and SLEEP are now darkVerb's in adv.t.

  - A new verb, breakVerb, has been added to adv.t.  The vocabulary
    words for this verb are 'break', 'destroy', and 'ruin', and it
    provides a single-object command "break <direct-object>".  The
    thing class has been adjusted so that verDoBreak(actor) validates
    breaking any object, but doBreak(actor) simply displays "You'll have
    to tell me how to do that."  If you want to make a breakable object,
    simply override doBreak(actor) so that it breaks the object (you may
    also want to override verDoBreak(actor) so that it doesn't allow a
    broken object to be broken again).

  - "there" has been added a synonym for "it" in the specialWords list
    in adv.t.  This allows sentences like this:

        >get box.  put ball in there.

  - lightsource now has a doTurnnon method in adv.t.  This method will
    show the room's description if the room becomes lit as a result
    of turning on the lightsource.  Note that lightsource, by default,
    has no verDoTurnon, so you can't turn a generic light source on
    and off.  However, if you add switchItem to the superclass list of
    a lightsource object, you will have a light source that you can
    turn on and off, and which will have this new behavior.  Note that
    you should put lightsource in the superclass list prior to
    switchItem, so that lightsource.doTurnon overrides switchItem.doTurnon:

        flashlight:  lightsource, switchItem
            sdesc = "flashlight"
            noun = 'flashlight' 'light'
            adjective = 'flash'
            location = tunnel
        ;

  - verIoGiveTo and ioGiveTo have been added to movableActor in adv.t.
    verIoGiveTo rejects the command if the actor is the same as the
    indirect object, otherwise the command is accepted.  ioGiveTo
    always rejects the offer.  In addition, ioGiveTo has been added
    to basicMe; the method always accepts anything from another actor,
    because this method will only be called in response to commands
    such as:

        >guard, give me the key

  - A small problem with thing.isVisible in adv.t has been fixed.  If
    the vantage is inside the object, and the object's contents are
    visible, isVisible returns true.  This is is needed in certain
    situations involving nested rooms.

  - moveableActor.travelTo(room) in adv.t has been corrected so
    that it does nothing when room = nil, which is the case when the
    actor can't travel in the desired direction.  Previously, the
    "noexit" message would be displayed, but then the actor would
    be moved into a nil location.

  - moveableActor now has a roomCheck method in adv.t.  The method
    is the same as basicMe's roomCheck method; its omission in
    previous versions was an oversight.

  - The compiler now sets an error code on exit.  If you are using
    a MAKE utility or other program-building tool, you can use the
    exit code.  On success, the compiler uses exit code 0; if any
    errors occurred, a non-zero exit code is used.

  - The compiler no longer creates a .GAM file if errors occurred
    during compilation.  If a .GAM file of the same name exists
    prior to a compilation, and errors occur, the original .GAM
    file is unaffected (it is not deleted or overwritten).  Although
    the compiler previously produced a .GAM file even when an error
    occurred, this .GAM file was not generally usable; to avoid
    confusion, the compiler no longer produces a .GAM file at all
    when an error occurs.

  - The compiler performs more checking for invalid memory options.
    When memory options are entered that exceed the compiler's
    internal limits, the compiler will report an error (after the
    Compile button is pushed) and halt the compilation.  The affected
    settings are the parse pool size, local symbol table size, and
    the stack size.  The runtime similarly checks its parameters
    more carefully now.

  - $$ABEND can now be used after a question from the parser, such
    as during disambiguation and when OOPS is permitted.

  - The runtime no longer displays anything on the status line at
    startup.  It initializes both the left portion (which normally is
    used to display the location) and the right portion (which is
    normally used to display the score and turn count) to empty
    strings.  To ensure that a score is properly displayed at the
    start of the first turn, we added a call to scoreStatus(0, 0) in
    the "init" function defined in std.t.

  - The runtime handles hyphenation better.  Multiple hyphens will
    no longer be split across lines -- so if you use two hyphens
    together for a dash, both hyphens will always be grouped on one
    line.  Furthermore, the runtime formatter will never put a dash
    at the very start of a line; if a line must be split at a dash,
    the formatter will put the dash at the end of the line, then
    break the line, and will back up and split at the previous word
    if necessary.

  - The runtime will now properly convert "\" sequences in askfile()
    prompts properly.  If you use a \n, \t, \', \", or \\ sequence
    in a prompt to askfile(), the sequence will be displayed as the
    appropriate character.

  - The Mac runtime's startup dialog has an additional option that
    lets a user show all files, rather than just files that the
    runtime recognizes as TADS game files.  This should make it
    easier to run a game transferred from another system -- since
    you can now run a game regardless of its type/creator settings,
    you can simply transfer a file from another operating system and
    run it directly.  To show all files, click the radio button
    labelled "Show All Files" at the bottom of the file dialog;
    to return to showing only TADS game files, click the radio
    button labelled "Show TADS Games Only."

  - The TADS Executable Game Builder now lets you specify run-time
    command options that should be used when the game is executed.
    This new feature, which is optional, lets you specify a set of
    run-time options that you want to be in effect every time your
    game is run.

    To specify command options for your game executable, you must
    first create a file.  Use the same format as CONFIG.TR -- simply
    enter your options into the file as you would on a TR command
    line; separate options by newlines or spaces.  For example, to
    specify a minimal cache size and a swap file of SWAP.DAT, you
    could make your CONFIG.TR file look like this:

        -m0 -tf swap.dat

    See the Author's Manual chapter on the run-time command-line
    options.  Even though the Macintosh version of the run-time
    doesn't normally use a command line at all, you must still enter
    options into a file using the command line option format if you
    want to combine them with your game.

    Once you've created a file with your command options, specify
    that file to the Executable Game Builder by selecting it with
    the new file selector dialog that appears after you specify the
    game file.  If you don't want to combine an options file with
    your game, simply cancel this dialog.

    Once the config file is bound into your executable, its options
    will be used every time a player runs the game.  Note that you may
    want to avoid specifying anything specific to your system, such as
    volume or folder names, since that may prevent the game from working
    properly on someone else's computer.

  - The Macintosh compiler's "memory options" dialog box has been
    corrected so that it accepts settings over 32767.  Memory settings
    up to 65535 can now be entered.

  - The Macintosh compiler no longer displays "Compilation Completed"
    when compilation fails or is interrupted.  Instead, it displays
    the new message "Compilation Terminated", to make it clear that
    the compilation did not complete normally, whenever errors occur
    during a compile, or the compilation is cancelled by Command-Period.

  - The Macintosh compiler has been corrected so that it doesn't add
    ".t" to the end of source file names any more.  In previous versions,
    the compiler always added ".t" to the end of a filename if the
    filename didn't contain at least one period; while this behavior
    is desirable on other computers (since it allows command-line
    users to omit the default filename extension, saving typing), it's
    unnecessary and incorrect on the Macintosh.

  - The Macintosh run-time's formatting system has been improved so
    that it will no longer insert spaces after hyphens.  Previous
    versions occasionally inserted a space after a hyphen, even when
    the original text had no spaces after the hyphen.

  - The new sentence parsing for the form VERB PREP IOBJ DOBJ
    (introduced in 2.1.1) causes a subtle problem:  if you create
    an object with an adjective that is also a preposition, the
    system attempts to interpret sentences with a single-word verb
    that refers to the object as VERB PREP IOBJ.  The result is
    this:

       >push off button
       What do you want to push?

    This is because the parser is interpreting the sentence as
    "push something off button", and needs to know the "something".
    This problem has been corrected.  Now, the parser will check this
    type of case to see if the preposition can also be used as an
    adjective, and if so, checks to see if a noun (possibly preceded
    by one or more adjectives) follows; if this test is met, the word
    will be interpreted as an adjective, as it should be.

  - The parser now correctly distinguishes between cases involving
    a word that is defined as both a preposition and an adjective.
    The parser previously did not accept sentences such as this:

      >enter south wall

    when 'south' was defined as an adjective.  Because 'south' was
    also defined as a preposition (in adv.t), the parser attempted
    to interpret this sentence as though 'enter south' were a verb
    (in the same manner as 'pick up' or 'put down').  The parser
    now checks to make sure that 'enter south' is a valid combination
    verb; if it's not, and 'south' is also defined as another part of
    speech, the parser assumes that 'enter' is the verb, and treats
    'south' as an adjective.

  - The parser previously asked to disambiguate a direct object twice
    if askio(prep) was used.  For example:

       >unlock door
       Which door do you mean, the large door, or the small door?

       >large
       What do you want to unlock it with?

       >key
       Which key do you mean, the silver key, or the gold key?

       >gold
       Which door do you mean, the large door, or the small door?

       >large
       The door unlocks with a satisfying click.

    This has been corrected -- the parser now only asks once about
    the door.

  - The parser did not previously accept a word during disambiguation
    if the word was defined as both a noun and an adjective.  For
    example, if you've defined objects "violet paper", "violet banana",
    and "paper towel", and the parser asked you this:

       >x violet
       Which violet do you mean, the violet paper, or the violet banana?

    then you couldn't respond with "paper".  This has been corrected.

  - The inputkey() function now clears the "more" line counter.  So,
    when inputkey() is called, a "more" prompt will not show up until
    another screenful of text has been displayed.

  - "local" statements that occur out of context (i.e., as other than
    the first statements after an open brace) now generate better
    diagnostics.

  - Dividing by zero is now flagged as a run-time error.

  - A problem involving the embedded string << >> notation has been
    corrected.  Under certain circumstances, if one expression used
    in an embedded string invoked another string with an embedded
    expression, an error occurred (usually "invalid type for built-in
    function").  This should no longer occur.

  - The system did not properly handle lists containing function
    pointers.  This has been corrected.

  - A problem involving pre-compiled headers and 'modify' has been
    corrected.  Several people have encountered problems that generally
    were manifested as "assert" failures in mcm.c (the cache manager)
    when using 'modify' and pre-compiled headers; these should no
    longer occur.

  - An internal cache corruption occurred under certain obscure
    circumstances involving 'modify'.  This has been corrected.

  - A note on roomCheck:  if you return nil from roomCheck, fuses
    and daemons are NOT run; in this sense, returning nil from roomCheck
    is equivalent to using abort in other methods.  (This is not a
    change -- it's always worked this way -- but this behavior is
    not mentioned in the TADS Author's Manual.)

  - A note on using << >> embedded strings:  If you put a newline
    immediately before the << of an embedded string, any spaces between
    the last non-space character preceding the << and the << will be
    lost.  If you want a space before the <<, do not put it on a new
    line.  Instead, you can put it at the end of the line, and put
    the embedded expression itself on the next line.  For example:

        embeddedString = "embedded string"
        sdesc = "This is a message with an
                 <<self.embeddedString>>!"     // wrong

    This will display as follows:

        This is a message with anembedded string!

    If you intend a space to precede the embedded string, you should
    write this as follows:

        sdesc = "This is a message with an <<
                self.embeddedString>>!";      // right

    (This is not a change, but simply a note for game developers who
    have encountered this problem.)



2.1.2  11/22/93  enhancements, bug fixes

  - You can now detect when the player uses multiple direct objects
    with a verb, and reject such commands.  Whenever the player uses
    multiple direct objects with a command (or uses "all", even if it
    results in a single object being used), the parser calls the
    verb object's rejectMultiDobj(prep) method.  If you don't wish to
    take any special action for multiple direct objects used with a
    particular verb, simply return nil from this method (or don't
    define the method at all for the verb).  If you want to prevent
    multiple direct objects from being used, however, you should display
    an appropriate message, and return true.  The parser will skip the
    command entirely.  Note that the parser doesn't display any additional
    message when rejectMultiDobj(prep) returns true; the method should
    display whatever message is desired.  The "prep" parameter is the
    preposition object used with the command; it will be nil if no
    indirect object is present.  An example:

        modify inspectVerb
            rejectMultiDobj(prep) =
            {
                "You can only look at one thing at a time.";
                return true;
            }

    The verb's rejectMultiDobj(prep) method is called immediately
    before the actor's actorAction method.  Note that the parser will
    continue processing any remaining commands on the line, and will
    then run daemons and fuses as normal, even if rejectMultiDobj(prep)
    returns true; if you want to stop the current turn altogether, use
    abort.

  - The player command parser now gives you greater control over object
    validation error reporting.  In previous versions, if an object was
    visible but did not pass the validIo/validDo test, the parser called
    the object's cantReach method to report the error (see the note below
    about an additional change to object.cantReach processing).

    Now, however, the parser will call verb.cantReach instead, if the
    command's deepverb object defines (or inherits) a cantReach method.
    If the verb does not have a cantReach method at all, the parser
    will use the old behavior instead.  The new cantReach method should
    be defined as follows:

       myVerb: deepverb
           verb = 'whatever'
           cantReach(actor, dolist, iolist, prep) =
           {
               // your code here
           }
       ;

    This method doesn't return a value; it simply displays the appropriate
    message explaining why the object can't be used with the command.
    verb.cantReach is used only when the objects are visible (that is,
    object.isVisible(actor) returned true for each object in the list).

    Only one of dolist or iolist will be non-nil.  If the direct object
    of the command refers to one or more objects that are visible but
    can't be used (according to validDo), dolist will be a list of all
    such objects, and iolist will be nil.  Otherwise, iolist will be a
    list of such objects used for the indirect object, and dolist will
    be nil.

    adv.t has not been changed to use verb.cantReach.  This change has
    been made to provide finer control for game authors implementing
    their own verbs and object validation procedures.

  - The player command parser had an odd quirk when ambiguous nouns
    were used with transparent items.  If the player used a command
    containing a noun that referred to multiple objects that were
    visible but were not valid for the verb (for example:  "take trophy"
    in a room containing a closed glass trophy case containing a bowling
    trophy and a tennis trophy), the parser asked the normal disambiguation
    question.  This was not really necessary, because the parser already
    knew that the objects were invalid.  This has been changed; the parser
    now simply uses the cantReach message for *each* object that is
    visible and matches the vocabulary, using the usual multiple-word
    format:
        bowling trophy:  You'll have to open the glass case first.
        tennis trophy:  You'll have to open the glass case first.

    This new behavior should have no effect on your game code.  Note
    that it is entirely irrelevant if you use the new verb.cantReach
    feature described above.

  - The compiler sports a new case sensitivity option.  By default,
    the compiler is case-sensitive, as it has been in past versions.
    However, the new toggle option allows you to change this.  Specify
    -case- to turn off case sensitivity (the default is -case+).  Note
    that this is a toggle option, so simply using -case will reverse
    the current case sensitivity (which is useful if you use a CONFIG.TC
    file that sets a non-default case option).  When case sensitivity
    is turned off, the compiler will treat upper- and lower-case letters
    in symbols (names of objects, properties, functions, and local
    variables) as equivalent.  Hence, foodItem = fooditem = FoodItem,
    and so on.

    If you create a pre-compiled header with -w, any compilation which
    reads that binary header with -l will use the same case sensitivity
    as was in effect when the header was pre-compiled.  The -case option
    is ignored when a pre-compiled header is loaded.  Likewise, the
    debugger uses the same case sensitivity that was in effect when the
    game being debugged was compiled.

  - The debugger's command set is no longer case-sensitive (hence,
    BP = Bp = bP = bp).

  - adv.t has a new darkVerb class.  This is a type of deepVerb that
    can be used in the dark.  The darkroom class has been changed to
    accept any verb of class darkVerb in its roomAction and roomCheck
    methods.  The travel verbs and system verbs have all been made
    darkVerb objects, so darkroom only needs to check the single
    verb type.

    In a related change, turnOnVerb and dropVerb have been changed to
    be darkVerb objects, allowing the player to turn on an object or
    drop it in the dark.  The verDoTurnon method in switchItem has
    been changed so that it checks to see if the player is in a dark
    room; if so, the item can only be turned on if the player is already
    carrying the object.  This allows the player to turn on a light
    source that's already being carried, but doesn't allow the player
    to pick up a light source in a dark room.

  - The compiler issues a new warning message (TADS-452) if you
    use the same verb with two deepverb objects.  The parser can only
    choose a single deepverb object for any verb typed by the player,
    so you should never define the same 'verb' vocabulary word in more
    than one deepverb object.  In past versions, the compiler did not
    flag this as a warning.

  - Several improvements have been made for numbers in player
    commands.  First, multiple numbers are now allowed in a single
    commands; for example, the player can now say "press 1, 2, 3,
    4 on keypad," and the numbers are set in numObj.value, one by
    one.  Second, the sdesc, adesc, and thedesc properties of
    basicNumObj have been improved to show the number's value.

  - Similar improvements to those for numbers have been made for
    strings.  Multiple strings are now allowed in a single command,
    and the basicStrObj properties sdesc, adesc, and thedesc have
    been improved to show the string's value.

  - specialWords has been enhanced.  First, in past versions, if a
    game contained multiple specialWords statements, the word lists
    were additive -- all specialWords lists were used in the game.
    This has been changed so that each specialWords statement replaces
    any previous list in effect.  However, you now can explicitly add
    to the specialWords list, without removing any of the previously
    defined words, by using "modify specialWords".  When you use
    'modify', you can use nil in any word slot if you do not wish
    to add any words for that slot.  Finally, you can use "replace
    specialWords" to make the replacement explicit; this is the default
    if neither 'modify' nor 'replace' is specified, but the compiler
    will now issue a warning (which is harmless) if you use specialWords
    without 'replace' or 'modify' and a previous specialWords list is
    already in effect.

  - The words "one" and "ones" (or their equivalent for your game,
    if you've changed them with specialWords) are no longer considered
    reserved words within normal commands.  This allows you to use
    objects such as a "one dollar bill"; previous versions rejected
    player commands containing "one" or "ones".  These words are now
    considered special only during the parsing of a response to a
    disambiguation question, when they can be used in place of a
    noun ("the red one" can be used in answer to "Which book do you
    mean...").

  - The hider class has been changed so that 'it' or 'them' (as
    appropriate) are set to the object or objects found when
    searching the hider.

  - The verDoPutIn and verDoPutOn messages in thing and surface
    (respectively) have been improved for the somewhat obscure case
    of attempted circular containment - that is, putting an object
    into a container, when the container is already in the first object
    (either directly or by virtue of being inside another object which
    is inside the first object, or inside an object which is inside an
    object which is inside the first object, and so on).  The new
    method thing.circularMessage(iobj) is called in these cases to
    display an appropriate message; the default implementation of this
    method displays the complete list of containers of the direct
    object out to the indirect object.  For example, if you have a
    crate which contains a box, and you try to "put crate in box",
    the message is "You can't put the crate in the box, because
    the box is already in the crate."

  - The default doTake method has been changed to include the weight
    of any contents of the item being taken, in addition to the item
    itself, to determine if the actor's inventory is too heavy.
    The old doTake method only included the weight of the object
    being taken, not counting its contents.

  - The Actor class has been changed to add a travelTo method.  You
    can now move any actor (Me included) with travelTo(destination).
    The default Actor.travelTo method moves the actor; it announces
    the departure of the actor if the actor was in the same location as
    Me before leaving (and the location is lit); and it announces the
    arrival of the actor if the actor is moving into the same location
    as the player (and the location is lit).  The departure message
    is generated with a call to self.sayLeaving, and the arrival
    message is generated with self.sayArriving.  The default versions
    of these methods simply display "Thedesc leaves the area" and
    "Thedesc enters the area", respectively; you can override these
    methods if a more specific message is desired.

  - When modifying a class object with 'modify', the modified object
    was not a class unless the 'class' keyword was included with the
    'modify' statement ("modify class foo" rather than "modify foo").
    This has been corrected; a modified class is still a class.

  - outhide(true) now returns a status indicator, which is a value that
    can be used in a subsequent call to outhide() to return output
    hiding to the state it was in before the outhide(true).  This
    allows you to nest text hiding.  When you use the nested form
    (which you do simply by using the return value of outhide(true) as
    the parameter - in place of nil - to the subsequent call to outhide()),
    the value returned by the second outhide() indicates whether any
    text output occurred ONLY BETWEEN THE NESTED CALLS.  For example:

     old_stat1 := outhide(true);
     "This is some hidden text.";
     old_stat2 := outhide(true);
     // write no text here
     new_stat2 := outhide(old_stat2);
     new_stat1 := outhide(old_stat1);

    Because outhide(old_stat2) indicates whether any output occurred
    during the NESTED outhide(true), new_stat2 = nil.  However, new_stat1
    = true, since output occurred after the first outhide(true).  Consider
    another sequence:

     old_stat1 := outhide(true);
     // write no text here
     old_stat2 := outhide(true);
     "This is some hidden text.";
     new_stat2 := outhide(old_stat2);
     new_stat1 := outhide(old_stat1);

    In this case, both new_stat1 and new_stat2 will be true, because
    hidden output occurred within both nested sections.

    The general form of a nested hidden output section looks like this:

         {
            local original_hide_stat;
        local nested_stat;

            original_hide_stat := outhide(true);
            // do whatever you want to do while output is hidden
        nested_stat := outhide(original_hide_stat);
     }

    Now nested_stat will indicate whether any output occurred during
    the nested outhide() - that is, between the outhide(true) and
    the outhide(original_hide_stat).  In addition, output hiding will
    be returned to the same state it was in prior to the original
    outhide(true).

  - The random number generator has been improved.  Many people have
    complained about the many undesirable properties of the old
    generator, especially when small upper limits were used.  The
    interface to the new random number generator is the same as
    before - call rand(upper_limit), which will return a uniformly
    distributed random number from 1 to upper_limit, inclusive.

    Note that the old random number generator will still be used if
    you don't call randomize().  This allows test scripts (which require
    a fixed sequence of random numbers in order to be repeatable) that
    were written with older versions to continue to operate unchanged.
    If you want numbers from the improved generator, be sure to call
    randomize().

  - When 'modify' was used on an object, the compiler sometimes did
    not correctly apply the original object's vocabulary and location
    to the new object.  This has been corrected.

  - restore() and undo() have been changed so that they always cancel
    all pending commands on the command line.  In the past, if the
    player typed several commands, and something happened (such as
    the player character dying) during one of the commands that led to
    an undo() or restore(), the remaining commands were still
    executed.  This has been fixed.

  - If you explicitly set an object's location to nil in its object
    definition, and the object inherited a location from a superclass,
    the system incorrectly placed the object in the contents list of
    the object named in the location inherited from the object's
    superclass.  This has been corrected.

  - "abort" can now be used within a daemon or fuse, and the
    expected behavior will occur.  In the past, "abort" within
    a fuse (or daemon) merely exited from the current fuse,
    but the remaining fuses and daemons were still executed.
    Now, "abort" will cause the entire turn to end; no more
    fuses or daemons will be executed on the current turn.


2.1.1  09/09/93  enhancements

  - You can now access objwords(1) while deciding whether to use a
    default direct object in doDefault.  This is useful mostly if
    you want to prevent players from being able to use "all" with
    certain verbs, but still want to generate a default direct object
    for the verbs.  To do this, you can detect when objwords(1) = ['A']
    ('A' is the parser's internal code for "all", which saves you the
    trouble of checking for "everything" and shorter abbreviations as
    well as "all"):

      doDefault(actor, prep, iobj) =
      {
          if (objwords(1) = ['A'])
          {
              global.allMessage := 'You can\'t use "all" with this verb.';
          return [];
      }

      /* your normal default object code goes here */
      }

    If you wish, you can also suppress the default message that the
    parser will generate ("I don't see what you're referring to").
    To do this, you'll have to write your own parseError() function
    and detect when an "all" violation has occurred (cleverly using the
    global.allMessage, which we set above for this purpose):

      parseError: function(str, num)
      {
          // if there's an allMessage waiting, use it instead of the default
          if (global.allMessage <> nil)
      {
          local r;

          r := global.allMessage;
          global.allMessage := nil;
          return r;
      }
      else
          return nil;
      }

  - The compiler's error message format has been changed slightly
    to work better with editors and workbench programs that scan error
    logs to go to lines with errors.  The format is now:

        file(line): error TADS-xxxx: message

    For example:

        deep.t(1151): error TADS-300: expected colon


  - The parser now accepts sentences of the form VERB PREP IOBJ DOBJ,
    where the PREP is *not* part of the verb.  For example, GIVE TO THE
    MAN THE BALL.  This change has two benefits.  First, while this
    type of sentence is not common in English, some other languages
    allow this type of phrasing, so the parser is now somewhat more
    adaptable to non-English languages.  Second, this allows for
    object defaulting and command completion when specifying just the
    indirect object, which was not possible before.  For example, if
    the player types ASK FOR A BEER, the parser will be able to attempt
    to provide a default (if one is available), or at least ask for the
    direct object.  Previous versions would simply say "I don't understand
    that sentence."  Note that the parser still attempts to combine the
    verb and preposition into a single phrase; the new action happens
    only when the verb and preposition don't go together (that is, they
    haven't been defined together as a "verb =" property of a deepverb).
    For example, suppose that a line like this appears in a deepverb:

        verb = 'pick up'

    In this case, PICK UP THE BOX will use THE BOX as the direct object,
    just as in previous versions.  Only when the verb-preposition combination
    is not specifically defined in a verb will the new phrasing be used.

  - When no preposition is specified between the direct and indirect objects,
    the parser will now evaluate a new property, nilPrep, in the deepverb
    object.  This property should return the preposition object that should
    be used as the preposition between the objects.  Previous versions of
    TADS always looked for an object that defined the word 'to' as a
    "preposition =" property.  While 'to' is almost always the correctly
    the correct preposition to substitute in English, it's obviously the
    wrong word in other languages; furthermore, the correct word in other
    languages is sometimes a function of verb.  If no nilPrep property is
    defined for the deepverb, the parser will still use the object whose
    "preposition =" property matches the word 'to'.

  - The class transparentItem in adv.t has been modified so it works better
    when you define an object that inherits from both transparentItem and
    container or openable.  First, an ldesc has been added so that the
    contents of a transparentItem are listed by default with the ldesc.
    Second, the "look in" command now works on a transparentItem.  In
    addition, the openable class has been changed so that the "look in"
    command can be used when an openable is also a transparentItem, even
    when the openable is closed (because you should be able to see the
    contents of a transparentItem regardless of whether it's open or closed).
    Thanks to Ron Hale-Evans for pointing out this problem and finding the
    solution.


Please consult TADSV200.MAC (available on the High Energy BBS) for
information on earlier releases.