DGD/ [ source navigation ] [ diff markup ] [ identifier search ] [ file search ] Version: [ 1.0.a0 ] [ 1.1 ] [ 1.2 ] [ 1.2p1 ] [ 1.2p2 ] [ 1.2p3 ] [ 1.2p4 ] [ 1.2.151 ]

   DGD 1.0.a0
   
   Differences with LPmud 3.1.2:
   
   Language:
   
    - No keywords "protected", "public" and "status".
    - Mappings, as in the mappings package that I made for LPmud, with one
      difference: there is no m_delete(), and the normal way to remove an
     index/value pair from a mapping is to set the value to 0.
   - Typechecking is more strict.  As in LPmud 3.1.2, functions are not
     typechecked if they have no declared type, but it is possible to enforce
     typechecking in all objects.
   - call_other() does not require a cast.  If the type is not clear from the
     context, a cast is recommended.
   - Types such as int**, string***** are possible.
   - Initializers are not supported.
   - Indexing out of range is not allowed on arrays and strings.  Negative
     indices can be used to offset from the end of the array/string (-1 last,
     -2 last but one, etc).
   - Indexed string assignments such as foo = "bar"; foo[0] = 'B'; are possible.
   - The zero size array and zero size mapping are not globally shared, and
     comparisions such as array == ({ }) will fail.
   - It is illegal to declare any functions, function prototypes or variables
     before inheriting.
   - Inheritance is completely different.  There are two kinds of inheritance,
     virtual and labeled.
     Virtual inheritance is the default.  If A is inherited by B and C, and D
     inherits B and C, then the variables of A are in D only once.  It is illegal
     to inherit two different functions with the same name, unless function F1 is
     inherited in the object that defines function F2, or if at least one of
     F1 and F2 is private.  It is illegal to inherit two different variables
     with the same name, unless at least one of them is private.  It is
     illegal to redeclare a non-private variable.  Private functions are
     private in the program that defines them, and cannot be used from inherited
     objects.  Private functions do not mask inherited functions, except in
     the program in which they are defined.  It is illegal to inherit two
     different instances from an object.
     Labeled inheritance uses the syntax inherit label "file"; Functions in
     labeled inherited objects can be accessed with  label::function();
     Variables in labeled inherited objects cannot be accessed from the
     current program at all.  Functions and variables need not be unique
     between labeled inherited objects.  It is possible to inherit the same
     object with labeled inheritance twice; the different instances will not
     share their variables.
   - There is an object that is automatically (virtually) inherited in all other
     objects, called the auto object for short.  The auto object is shared
     even between virtual inherits and labeled inherits.
   - Predefined functions are called kfuns (kernel functions); the kfuns and
     the non-private functions declared in the auto object together are called
     efuns.  Kfuns are assumed to be static functions inherited in the auto
     object, with the added limitation that they cannot be called with
     this_object()->kfun().  All static functions declared in the auto object
     share this limitation.
   - There is no class_specifier inherit "file"; This did not work in LPmud 3.1.2
     anyhow.
   - Function prototypes are always inherited together with the function.
   - Function calls are typechecked if the called function is typechecked.  It
     is illegal to call a non-varargs function with the wrong number of
     arguments from a typechecked function, even if the called function is
     not typechecked itself.
   - Kfuns are not treated differently from other inherited functions, so
     destruct(this_object(), this_object()); will not cause a compile-time
     error in an untypechecked function.
   - Inherited functions may be redeclared with a different prototype.  If
     an inherited function is redeclared with a prototype only, and the function
     itself is not declared in the same program, then all calls to the function
     from that program will call an undefined function, which will result in a
     runtime error.
   - If object A declares function F, and B has only a prototype for function
     F, calls to F from B will call function F in A if A and B are inherited
     in the same object.
   - It is illegal to inherit a function and a prototype for the same function
     if the prototypes do not match.
   - A call to an undeclared function from an untypechecked function implicitly
     declares a prototype for the undeclared function that matches anything.
   - this_object()->function(); can be used to call static functions, but not
     private ones.
   - foo->bar(gnu); is merely an alias for call_other(foo, bar, gnu);  It is
     therefore possible to redefine call_other() entirely.
   - lock(expr); will evaluate expr without regard of execution cost, and with
     extra space on the function call stack.  It can only be used by the auto
     object to ensure that execution does not halt inside a critical function.
   - Any kfun can be redefined, just as ordinary inherited functions can.
     catch() and lock() are not considered to be kfuns (they are not true
     functions because catch(foo, bar) does not "call catch with two arguments").
  
  Compiler:
  
   - The built-in preprocessor conforms to the ANSI standard, except for the
     following:
      - No trigraphs.
      - Successive string constants are not concatenated (use the + operator
        instead).
      - The suffixes U and L are not allowed on integer constants.
      - No floating point constants.
   - There is a standard include file which is included automatically.
   - All #pragma directives are ignored.
   - All integer constants may be in decimal (starting with 1-9), octal (starting
    with 0), hexadecimal (starting with 0x) or a character constant 'x'.  The
    only escaped characters that are translated into something else in
    character constants and string constants are \t and \n.
  - The compiler is two-pass.  In the first pass, the function is typechecked
    and a parse tree is constructed.  Constant folding and removal of dead
    code is done.  In the second pass, code for a virtual stackmachine is
    generated.  Jumps to jumps are optimized.  Optionally, the second pass
    may generate C code (not yet implemented).
 
 Interpreter:
 
  - The interpreter has only 32 instructions.  Kfuns are not part of the
    interpreter proper.
  - Objects are pure programs.  They do not have inventories, environments,
    are not alive, do not have actions (all of this can be simulated).
  - Pathnames without a leading slash are considered to be relative to the
    directory of the current object (i.e. /foo for the object compiled from
    /foo/bar.c).
  - create() is called if a function in an object is called for the first
    time.  It is not called if an object is loaded because it is inherited.
    If it is desired that reset(0) is called instead, add the following to
    the auto object:
 
         void reset(int arg) { }
 
         nomask void create()
         {
             reset(0);
         }
 
  - reset() is never called by the driver.  Both reset on reference and reset
    after a fixed period are easily simulated.
  - clean_up() is never called by the driver.
  - Text typed by a user is passed on by calling receive_message(text) in the
    interactive object.  The kfun send_message(text) can be used in interactive
    objects to send text back to the user.
  - There is no "master object" as in LPmud 3.1.2, but a "driver object"
    instead (there is nothing masterly about it in DGD).  It is used only to
    translate pathnames for #include and inherit, and to supply the object
    that is used for interactive connections.  It does not inherit the
    auto object, unless this is done explicitly.
  - There is no shadowing.
  - The default state of an object is swapped out.  Strings and arrays are
    only shared inside objects.  If an array is exported from one object to
    another, it will become a different array as soon as the object is swapped
    out (this is guaranteed never to happen during execution).
  - Self-referential datastructures will be deallocated when no more outside
    references exist, because they do not belong in any object.
 
 Kfuns: DGD has about half of the kfuns of LPmud 3.1.2:
  - No kfuns such as environment(), this_player(), add_action().  Simulate them
    if you want them.
  - There is no exec(), heart_beat(), wizlist() (simulate them).
  - No parse_command().  It cannot be simulated, so people might want to port
    it to DGD, but it will never become part of "pure" DGD.
  - No alist kfuns.  I prefer mappings, even if alists are more powerful.
  - All file kfuns are unprotected.  To get either native or compat mode
    security, make the proper redefinitions in the auto object.
  - The built-in editor uses a temporary file and is very close to ex.
  - call_other() is typechecked if the called function is typechecked.  Calling
    a function that does not exist results in an error if the call has
    arguments (I still have to think about this).
  - There are no optional flag arguments to any kfun.
 
 DGD 1.0.a1
 
  - ALLOCA() and AFREE() have replaced some instances of ALLOC() and FREE(),
    and be used to allocate memory with alloca(), if available on the host.
  - Mappings are now partially hashed.  If a mapping grows by assigning to
    an index/value that doesn't exist yet, the index/value pair is stored in
    a hash table.  Mappings are converted to sorted arrays of index/value
    pairs when swapped out.
  - Fixed some bugs in the compiler, interpreter and kfuns.
  - Changed the way line numbers are stored.  The interpreter no longer
    maintains the current line number at runtime.
  - Added int-only versions of some kfuns to speed up integer arithmetic in
    typechecked programs. Typechecked functions are now typechecked at runtime
    as well, to ensure that integer arguments are really integers.
 
 DGD 1.0.a2
 
  - Better dead code removal.
  - Mixed return values are cast to int if needed.
  - Lvalues as function arguments are now handled properly.
  - Fixed a problem with (exp1, exp2) in aggregates and function arguments.
  - More untypechecked expressions are optimized.
  - String constants are marked as such.
  - Driver object has been enabled.
  - It is now illegal to call any function with too many arguments, even if the
    function has class vararg.
  - I removed the error on call_other() to a non-existing function.
  - When an object is cloned, or a function is called in it for the first time,
    create() in the object will be called.  
  - Added config file which is read on startup.
  - All ANSI escape sequences are now recognized in string constants and
    character constants.  Fixed a bug with #arg in macros.
  - Created proper main loop that reads input and calls receive_message() for
    the associated objects.
  - Created (single user) comm package.  DGD now works as a regular game driver.
  - Overview of functions called by the gamedriver (can be static):
    In the driver object:
     * void initialize()
         Initialize the mudlib.  Called once at program startup.
     * string path_ed_read(object, string)
         Path translation for editor read.
     * string path_ed_write(object, string)
         Path translation for editor write.
     * string path_object(object, string)
         Object path translation (for find_object, clone_object, etc).
     * string path_inherit(string, string)
         Inherit file name translation.
     * string path_include(string, string)
         Include file name translation.
     * object compile_object(string)
         Called if the given argument could not be compiled.  The driver
         object can return an object that will be renamed to the wanted
         object.  The returned object may be a clone, and will remain
         a clone (i.e. may not itself be cloned), even with the new name.
         Modelled after "virtual objects" in MudOS, the American LPmud brand.
     * object connect()
     * void log_error(string, string, string, int)
         Log a runtime error.
     * string compile_log(string)
         Return the name of the file to which compile time errormessages
         should be appended.
    In the user object:
     * void open()
         LPmud: login
     * void close()
         Called if the user connection to the mud is closed.
     * void receive_message(string)
         Called for user input.
    In an object that uses the editor() kfun:
     * void receive_message(string)
         Called for editor output.
  - Overview of the kfuns added:
     * varargs mixed call_other(mixed, string, ...);
     * object this_object();
     * varargs object previous_object(int);
         Return the previous object n+1 steps back in the call_other chain.
     * object clone_object(string);
     * void destruct_object(object);
         LPmud: destruct()
     * string object_name(object);
         LPmud: file_name()
     * object find_object(string);
     * string function_object(string, object);
         LPmud: function_exists()
     * object this_user();
         LPmud: this_player(1);
     * string query_ip_number(object);
     * object *users();
     * int strlen(string);
     * mixed *allocate(int);
     * int sizeof(mixed *);
     * mixed *map_indices(mapping);
         LPmud + mappings: m_indices()
     * mixed *map_values(mapping);
         LPmud + mappings: m_values()
     * int map_sizeof(mapping);
         LPmud + mappings: m_sizeof()
     * int intp(mixed);
     * int stringp(mixed);
     * int objectp(mixed);
     * int arrayp(mixed);
         LPmud: pointerp()
     * int mappingp(mixed);
     * void error(string);
         Cause an error.
     * void send_message(string);
         Send a message to the current object (should be interactive user),
         messages from the user will call receive_message() in the object.
     * int time();
     * varargs void call_out(string, int, ...);
     * int remove_call_out(string);
     * void shutdown();
 
     * void editor(string);
         Handle an editor command, such as "e file", "%s/foo/bar/g", "x".
         If no editor instance exists for the current object, it will be
         created; editor output will call receive_message() in the object.
     * string query_editor(object);
         Return the editor status of the object ("command", "input" or 0).
     * void save_object(string);
         LPmud: save_object() without .o tagged on.
     * int restore_object(string);
         LPmud: restore_object() without .o tagged on.
     * varargs string read_file(string, int, int);
         LPmud: read_bytes()
     * int rename_file(string, string);
         LPmud: rename() (limited, will not rename directories if the
                host doesn't support this)
     * int remove_file(string);
         LPmud: rm()
     * varargs void write_file(string, string, int);
         LPmud: write_bytes(), will append if third argument is omitted.
     * int make_dir(string);
         LPmud: mkdir()
     * int remove_dir(string);
         LPmud: rmdir()
     * mixed **get_dir(string);
         Get file info using get_dir(file), directory info using
         get_dir(dir + "/" + pattern), the pattern can have ? * [a-z].
         The return value has this form:
             ({ ({ names }), ({ mod times }), ({ sizes }) })
         This is almost compatible with MudOS, except that directories have
         size -2 (non-existing files and special files are not included).
 
     * varargs string crypt(string, string);
     * string ctime(int);
     * string *explode(string, string);
     * string implode(string*, string);
     * int random(int);
     * varargs int sscanf(string, string, ...);
         As in LPmud, but also handles %*s (skip assignment), %s%d and %%.
 
 DGD 1.0.a3
 
  - Replaced objkey with separate fields in both objects and values.  Structure
    alignment on sun4 systems caused the size of a value to be 12 bytes, where
    it should have been 8.  It should now be 8 bytes on any host (as long as
    uindex is an unsigned short, and pointers use 4 bytes).
  - Redeclaring an inherited function with different parameters is now allowed
    (runtime typechecking will handle calls from inherited objects to the new
    function), but the return type still has to match.
  - Fixed a bug with the return type of an implicit prototype, which should
    read as mixed, when used.
  - Some checks to see if the result of path_file() was NULL were missing.
  - Removed time_interval from the configuration parameters.  If I'm going to
    support call_out intervals of less then a second, I'll do it in a different
    way.
  - The simulated rename() erroneously removed the destination if it existed.
  - Some checks for destructed this_object() in kfuns removed.  Either the
    error is caused from path_object(), or there was not real reason to block
    the kfun (file I/O).  Doing a call_other() from a destructed object is still
    illegal.
  - Special files are no longer excluded from a get_dir() listing.
  - Fixed some bugs in the compiler, where functions from different inherited
    objects were confused.
  - The type of the objcnt field in the value struct has been changed into
    Int, to save space on hosts that have 64-bit longs.
  - Replaced all variables called "index" by "idx".  index() is a function like
    strchr() on some systems.  Sigh.
  - Fixed a bad bug in integer comparisions.
  - The call_outs configuration parameter now specifies the maximum number of
    call_outs in all objects together, rather than per object.
  - The maximum execution cost is now set to the appropriate value at runtime
    (25% for call_outs), rather than once at initialisation.
  - call_out() and remove_call_out() now work.  The gamedriver is fully
    functional for a single user.
  - DGD now automatically generates a file called "limits.h" in the first
    include directory, which describes the sizes of datatypes and resources.
  - Fixed a problem with dumping function call traces of destructed objects.
  - Fixed several bugs in get_dir() and path_resolve().
  - Fixed a bug which occurred if a variable was defined with a name that had
    been used in an inherited object.
  - Destructing a destructed object gives an error, rather than a fatal error.
  - call_other() from a destructed object no longer results in an error, but
    is simply ignored, like in LPmud.
 
 DGD 1.0.a4
 
  - TCP/IP support added.
  - Reduced the amount of runtime stack checking, by computing in advance (an
    estimate of) the maximum stack depth of a function, which is checked when
    the function is called.  This takes two bytes extra per function.
  - Indexed string assignments will not make a copy of the string, if the string
    is not a constant and has reference count 1.
  - Fixed several bugs in the interpreted code generator.
  - Added LPC->C code generator.
  - Cleaned up Makefiles and including files a little bit (still far from
    perfect).
 
 DGD 1.0.a5
 
  - Removed some redundant code from restore_string().
  - this_user() was not always 0 in call_outs.
  - call_other() to a function with the wrong number of arguments does not cause
    an error, even if the function is typechecked.  This was already so for
    version 1.0.a3, but slipped from the log.
  - Fixed some typecasting errors in str_range() and arr_range().
  - Instances of an object on the stack were not properly wiped out when the
    object was destructed.
  - Fixed a bug in the C code generator, which didn't remove errorcontexts
    properly.
  - catch() within lock() no longer turns off the lock.  If used by the driver
    object, code within catch() will run with the execution cost reset.
    initialize() in the driver object will no longer be called with a lock.
  - Fixed a bug in remove_call_out, which could instead remove a similar
    call_out in an object that was already destructed.
  - It is now possible to redefine an inherited typechecked function as
    untypechecked.
  - Fixed a bad bug which caused the wrong inherited object to be used as the
    program in a function call.
  - map_sort() will now remove index/value pairs with the value set to 0.
  - Check exec cost if a creator function is about to be called.  This prevents
    half-initialized objects due to exec cost problems.
  - Fixed a bug in the < <= > >= operators on strings.
  - Max exec cost in call_outs is now 1/2 instead of 1/4.
  - Fixed a bad memory leak in array.c .
  - Exchanged the place in the array returned by get_dir() of the file sizes
    and the file mod times; it is now ({ names, sizes, times }).  It used to be
    different for compatibility with MudOS, but their doc turned out to be
    faulty. :)
  - Changed comm.c to handle INTR and DEL in telnet.
  - Fixed a bug in restore_object(), which would get stuck in an infinite loop
    when restoring an object without saveable variables.
  - Swapping enabled.
  - Fixed a bug that caused a bad program index in a function call to be
    generated.
  - Fixed a problem having to do with a full input buffer in comm.c .
  - Fixed a bug in save_object and restore_object, where the offset of variables
    in inherited objects was not properly calculated.
  - Fixed a memory leak in the generation of prototypes by calling undefined
    functions (only in untypechecked objects).
  - String hash table sizes are now powers of two.  They used to be primes,
    which is fairly pointless in this implementation.
  - Divided allocated memory into 'static' and 'dynamic' memory.  Static memory
    is used for things which need to be kept when everything is swapped out,
    and dynamic memory is used for the rest.
  - Fixed a bug with escape sequences in the preprocessor, and a related bug in
    the parser.
  - this_user() is now set during the call to open() in the user object.
  - Fixed bugs in the C code generated for catch() and ?:.
  - Inheritance with a label no longer specifies that a different type of
    inheritance is required (!).  Functions may now be inherited more than once,
    as long as the inheriting object redefines them.  A label can still be used
    to specify which inherited instance of a function is to be called.
  - Negative indexing has been removed.  Sorry, but I added them without
    considering the arr[0 .. x-1], with x = 0 problem.  (If only indices
    started at 1 instead of 0...)
  - Fixed a memory leak in mappings with destructed objects for indices/values.
  - Fixed a bug with destructed objects as arguments to call_outs.
  - Fixed a cleanup problem in case an object could not be compiled.
  - New kfuns:
     * get_exec_cost()
         Return the allowed execution cost that is remaining.
     * varargs int *status(object)
         Return status information.  The 'fields' of the returned array are
         described in the automatically generated include file "status.h".
     * void swapout()
         Swap out all objects.
 
 DGD 1.0.a6
 
  - Fixed a problem in kfun/debug.c in case RUSAGE was defined, but DEBUG was
    not.
  - Included size of tables in O_PROGSIZE, as given by the status() kfun.
  - Fixed an overflow problem in integer case ranges.
  - Renamed config option "reserved_stack" to "reserved_cstack", and added
    "reserved_vstack".
  - Both the renaming of and the renaming to the auto object and the driver
    object is now illegal.
  - Repeated call_others to the same function are now faster on average.
  - The control blocks of precompiled objects are swapped out no longer.
  - Fixed a bug in the editor substitute command, which could mess up if
    substitutions occurred and didn't occur on alternate lines.
  - Fixed a possible memory leak in restore_array and restore_mapping, in
    case the save file was faulty.
  - Fixed a bug with global integer variables as lvalue arguments to sscanf()
    in typechecked functions.
  - Improved some compiler error messages.
  - A new prototype for an inherited function won't replace the inherited
    function anymore, if the prototypes are identical.
  - Function calls with too few or too many arguments no longer cause runtime
    errors.  It caught a lot of errors, but also broke some code which
    shouldn't have.
  - Fixed a bug in inheritance, which could fail if two inherited objects
    defined the same function, and a third was unloaded.
  - Fixed a bug in calls to functions for which an undefined prototype was
    inherited, but which were redefined.
  - Changed _time, _ctime, _opendir, _readdir, _closedir and _alarm into
    P{_*} to make it work on HP systems.
  - Telnet GA is now only sent after a (possibly empty) prompt, and not
    after any finished output.
  - Made BEL, BS, HT, LF, VT, FF and CR host-independent.  Moved the adding
    of CR before LF back into comm.c (was in host/unix/connect.c in version
    1.0.a5).
  - State dumps:
    swapout() and shutdown() now take a numeric argument.  If non-zero,
    a state dump is created on the file specified by the dump_file config
    parameter.  A state dump file can be used on startup (by specifying it
    as the 2nd argument) to restore from.  After a successful restore,
    driver->restored() is called, rather than driver->initialize().  User
    objects and editor objects are not restored as such, and the driver
    object should deal with them in restored().  This can be done by
    registering those objects, just before the state dump occurs.
  - Ellipsis can now be used to declare a function with arbitrary numbers
    of arguments.  Example:
 
         varargs string sprintf(string format, mixed args...);
 
    args will have type mixed*, and will be an array with the additional
    arguments.  Ellipsis can also be used in a call, to push all elements
    of an array on the stack as arguments:
 
         call_other("/some/thing", "foo", array_with_arguments...);
 
  - Replaced time_t with long everywhere to make things portable.  If a time_t
    doesn't fit in a long on a particular host, it will have to be truncated.
  - Speeded up remove_call_out().  Removing a short-term call_out is now
    reasonably fast.
  - Added find_call_out().  I previously left it out because I considered
    using it bad programming practice.  I still think so, but it might be
    useful in some rare cases, and the current implementation is fairly fast.
  - All of x[y .. z], x[y ..], x[.. y] and x[..] are now possible, with the
    obvious meanings.
  - The swapfile and editor tmpfiles are now removed on a shutdown.
  - Fixed a bug in the compiler, which would not always cast the result of
    a function call to int when this was needed.
  - Errors inside a catch are now logged on stderr as well.
  - Fixed a problem which occurred when a catch was used in a conditional
    context in LPC->C code.
  - Fixed a problem in the compiler, which could produce a bad symbol table
    for the auto object (which fortunately isn't normally used).
  - If a clash between inherited functions occurs, only the clashing functions
    will be listed, rather than all functions that are inherited more than
    once.
  - Better removal of unused call_out slots in objects.
  - sscanf("foobar","foo%s") will result in an error.
  - New kfun: call_trace().  It returns the call trace as an array (see the
    doc for specifics).
  - driver->log_error() is now called (locked) with two arguments, the error
    string and a flag which indicates if the error is caught.  It should make
    use of call_trace().  The driver itself no longer logs runtime errors.
  - If an object is inherited that itself inherits an object that has been
    destructed, call driver->recompile(obj).  The driver object must destruct
    the object to force it to be recompiled, if this is desired.
  - A missing #endif would not always give an error.
  - Using a void value when typechecking now gives the error "void value not
    ignored" always.
  - Added mapping - array and mapping & array.
  - Functions with a declared non-void type must return a value.
  - Variables could erroneously be redeclared as private in the same object.
  - Redeclaration of an inherited function or variable will now give the
    inherited object in the errormessage.
 
 DGD 1.0.a7
 
  - Fixed a bug with saving large numbers in arrays and mappings.
  - Improved memory allocation in case sizeof(long) > 4.  Also improved
    efficiency for the case that DEBUG is not defined.
  - String hash tables are no longer cleared before being deleted.  Some hash
    tables used by the compiler which were previously statically allocated are
    now dynamically allocated.
  - The >> and << operators now shift unsigned values, so the result is
    identical on all hosts.
  - Fixed a memory leak in i_index() and i_index_lvalue().
  - Comm.c can now deal with ^Z as well.
  - Cleaned up the inheritance logic in control.c, and removed some bugs.
  - Fixed several bugs in the restoring of object names.
  - Fixed some code in switch_str(), which would only work properly for the
    auto object and driver object.
  - Replaced longs by Ints in the editor, to save space on hosts with
    sizeof(long) > 4.
  - Fixed a bug in c_tst() and c_not().
  - Changed the alarm/timeout interface.  co_call() now calls P_timeout()
    to determine if an alarm timed out; co_timeout() has been removed.
  - main() is now in local.c, and should call dgd_main(argc, argv).
  - All occurrances of fprintf(stderr, ...) replaced with P_message(...) .
  - path_object() (call_other, clone_object, find_object) from the auto
    object will no longer call the driver object to translate the path.
  - Fixed yet another problem in the C code generated for catch().
  - Added function name comments to generated C code.
  - The class specifier private no longer implies static, for variables.
    This means that private variables can be saved with save_object(), and
    restored with restore_object().  To get the old behaviour, use both
    static and private.
  - A new kfun is added, dump_state().  swapout() and shutdown() no longer
    do a state dump through a flag argument; dump_state() should be used
    instead.  dump_state(1) will create an incremental dump on top of an
    old one.
  - Fixed a possible memory leak in sscanf().
  - Fixed a bug in src/host/unix/connect.c which could hang the driver.
  - Made IAC GA optional.  The client must request it with IAC DONT TELOPT_SGA,
    which the driver will respond to with IAC WONT TELOPT_SGA.  I badly
    underestimated the number of faulty clients, and even plain telnets could
    not handle it.
  - Editor marks and secondary buffers were not cleared in between edits.
  - In the editor, changing a line into nothing could cause a crash.
  - Added a float type.  Fairly useless for muds, but not for other
    applications.  Everything has been adapted (save_object, sscanf), but
    apart from floatp no kfuns have been added yet.  Four new builtin kfuns,
    ADD1, ADD1_INT, SUB1, SUB1_INT have been added.
    The float type has 1 sign bit, 11 exponent bits and 36 mantissa bits.
    The format is basically a truncated IEEE double, with a few alterations:
    exponent 0x7fff is illegal, and there is no gradual underflow.
  - Fixed various minor bugs in the compiler.  Also made runtime typechecking
    more strict, and improved optimisation.
  - The dataspace of destructed objects that are not freed for some reason
    is now deleted right away.
  - The object argument has been removed from driver->path_ed_read(),
    driver->path_ed_write() and driver->path_object().
  - intp(), floatp(), stringp(), objectp(), arrayp() and mappingp() have
    been replaced with a single kfun, typeof().
  - The swapfile is not created before sectors are actually written to it.
  - A float.h file is now created on startup.
  - Added 2nd swapout measure for last five minutes.
  - Renamed config parameter swap_sector to sector_size.
  - Added some kfuns: fabs(), floor(), ceil(), fmod(), frexp(), ldexp(), modf().
  - Floats (both global and local) are initialized to 0.0, rather than integer 0.
  - Added time of compilation to control block struct.
  - Callouts have been changed: call_out() now returns an integer > 0, which
    must be given as an argument to remove_call_out() to remove it.  The kfun
    find_call_out() no longer exists.  status(obj) gives a list of all callouts
    in an object.
  - Renamed port_number to telnet_port, added binary_port (dummy, for now).
  - Reorganized status() and limits.h .
  - Fixed several bugs in the handling of callouts, which could result in random
    memory trashing.
  - Fixed some bugs in control.c for sizeof(int) == 2.
  - Fixed a bug in the swapping of large mappings.
  - Some more editor bugs fixed.
  - In the editor, use of | is restricted to inside global commands.
  - editor() no longer sends output to receive_message() in the editor object,
    but returns it as a string.
  - The optimizer has been made a separate part of the compiler.
  - dump_state() changed again: it will now sync the swapfile, append some
    tables at the end, and move it to a dump file.  Afterwards, the driver will
    read from the dump file to reconstruct the swap file at low priority.
    Incremental dumps no longer exist.
  - The swapfile was not always created before a dump was made, resulting in
    a fatal error.
  - float.h and float.c have been renamed to xfloat.h and xfloat.c, respectively.
  - The maximum stack depth of a function call with one argument was not
    computed correctly.
  - Multiple inheritance of the same file in different ways could, in some
    cases, lead to invalid fcall and variable offsets.
  - Fixed a bug that caused spurious stack overflow errors.
  - Fixed a problem with expressions of the form (a) ? (b, c) : d.
  - Dead code is now silently thrown away, instead of resulting in a
    "statement not reached" error.
  - Changed #include "float.h" to #include "xfloat.h" in generated C code.
  - Fixed a bug in the optimizer which mangled sscanf() assigned value checks.
  - The replies to DO TELOPT_SGA and DONT TELOPT_SGA were accidentally reversed.
  - Lexical errors were repeated for each rescanning of the input.
  - Some improvements in the typechecking for mixed... .
  - Enabled binary port.
  - Fixed a bug with # define foo "gnu.h" \n # include foo
  - Some bugs in binary connections fixed.
  - Fixed a bad bug in comm.c which could hang the driver.
  - Fixed a newly introduced lexical scanner problem.
  - get_dir("/a/b") returned "a/b" as the name of the file, instead of "b".
  - Oops, several private variables with the same name would each be saved with
    save_object().  Private for variables made to imply static again.
  - Filename matching in get_dir() made more efficient (thank you, Aedil).
  - Fixed a bug in && and || used as standalone expressions.
  - Dump files now include a kfun table.  This enables the driver to restore
    a dump file that was made by a driver version with fewer kfuns.  As long
    as no kfuns are removed and the interpreter itself is not changed, dump
    files can be used with future driver versions.
  - Let (x, 0) match any type but float in situations where 0 would.
  - The command line restore file argument is taken to be relative to the
    current directory at the time, rather than relative to the mudlib directory.
  - Makefiles brought up to date.
  - (int) 0.0 yielded a wrong value.
  - Max execution cost is no longer halved during a callout.
 
 DGD 1.0.8
 
  - Fixed a problem with catch(x, y) and lock(x, y).
  - Fixed file descriptor leak in swap.c.
  - Fixed a bug in swap.c which could cause confusion between sectors just
    after a state dump.
  - Removed "*** State dumped." message after a state dump.
  - Fixed a bug in the editor which could result in an infinite loop.
  - Changed the default return value of float functions to 0.0.
  - SunOS 4.x appears to have a problem: sometimes an alarm will interrupt
    a read or write on a file, even though this is supposed to be impossible
    and SV_INTERRUPT is not set.  As a workaround, a new timeout handler is
    provided that doesn't use alarms.
  - Fixed a bug in the C code generated for ++ and -- of non-integer variables.
  - Using memcmp() in str_cmp() was unwise, because the lexical ordering of
    characters may differ per host, and on a NeXT memcmp() is buggy.  Replaced
    with explicit code that compares unsigned characters.  This may invalidate
    old dump files for hosts with signed character compare in memcmp() !
  - If the swap file cannot be renamed to the dump file, attempt to copy it
    instead.
  - Cleaned up host.h a bit.  GENERIC_* no longer uses alloca() to make it
    more generic.
  - Fixed a bug in the editor which in extremely rare cases might wipe out
    a line.
  - Added newline-in-input optimisation as per Dark's networking package.
  - Made it impossible for the editor to read a directory.
  - A file can only be removed or renamed if the host system permits write
    access.
  - Avoided some typecast warnings.
  - Fixed the following bug:  int i, string s; i = 2; s = s + i;
    This used to give the integer value 2 to s.  Now s gets the value "02".
    As a corollary, casting from int/float to string and from string to
    int/float is now possible.
  - Fixed a bug which occurred if a function for which an implicit undefined
    prototype was created was defined as private in the same object.
  - Fixed a bug that prevented restoring a state dump made by a driver with
    fewer builtin kfuns.  Unfortunately, the bugfix affects state dumps too,
    and old state dumps can no longer be used. (!)
  - Added a summand operator to transparently compute expressions of the form
 
     x1[a .. b] + x2[.. c] + x3[d ..] + x4 + .. + xn[..]
 
    without intermediate results, as suggested by Aedil.
  - Discarded the 'a' in the version number; DGD is beyond the alpha stage.
  - call_trace() now also includes the function arguments.  It is the
    responsibility of the mudlib programmer to make sure that this doesn't
    cause security problems (this also applies to status(obj)[O_CALLOUTS]).
  - Fixed a bug which in some cases prevented proper removal of unreachable code.
  - Fixed an optimisation which was skipped in conjunction with the summand
    operator.
  - Fixed a bug which caused <digits>. to be rejected as a valid floating point
    constant.
 
 DGD 1.0.9
 
  - call_trace() could give incorrect arguments for varargs functions.
  - Fixed a bug which could occur for strval[i] = intval.
  - Attempt to use telnet linemode.  This makes *BSD telnet usable, let's hope
    nothing else breaks.
  - Fixed a bug in code generated for switch statements which only have a
    default entry with break statement.
  - Fixed an overflow problem in the array/mapping sort compare function.
  - DGD will now compile without warnings using gcc 2.4.5 -ansi -pedantic.
  - Fixed a bug in telnet subnegotiations.
  - Fixed some other ANSI C pointer problems.
  - The driver can now call static functions in the auto object.
  - Found a crasher in str.c::str_put() that had eluded me for quite a while.
  - Undid the static function patch (dumpfile incompatibility and other
    problems).
  - Made state dumps for which the whole swapfile was copied in one go more
    efficient.
  - 'make a.out' will now always relink a.out.  This fixes a dependency problem.
  - Global commands in the editor would crash with a bad regular expression.
  - Widened the size limits for arrays and mappings somewhat.
  - The precompiler will accept an optional 3rd argument, the output file.
    This file will be removed if an error occurs during precompiling (fixing
    another dependency problem).
  - Turned off type errors for ?: .  In case of a type conflict, the result
    type is mixed.
  - Extended status() array with some limits, also in status.h (needed for
    continuous muds).
  - Added array | array (A + (B - A)) and array ^ array ((A - B) + (B - A)).
  - String and array reference counts are now 4 bytes, instead of 2.
  - Fixed a bug that could remove code with a case label inside.
  - Translate std include file to a local filename before using it.
  - Removed spurious path_file() from path_object().
  - Added path_unfile() to translate a filename in host format back to DGD
    format.
  - Fixed a problem regarding mapping aggregates with identical indices;
    calling error() from within qsort() might leave the mapping in an
    inconsistant state.
  - Changed YYDEPTH into YYMAXDEPTH in config.h; this should work for a wider
    range of yaccs.
 
 DGD 1.1
 
  - Fixed a bug that caused precompiled kfun calls to be wrong if kfuns were
    added since the last state dump.
  - The type of (expr1 ? void : expr2) and (expr1 ? expr2 : void) is now always
    void.
  - Fixed another bug in switch statements with only a default label inside.
  - Made sure that mappings are compacted before the size is checked.
  - Fixed a bug that might occur while restoring object filenames in a state
    dump.
  - DUMPFILE COMPATIBILITY ABANDONED.  All following pre-1.1 versions won't be
    dumpfile compatible with 1.0.9 and probably not with eachother, either.
    I'll make a dumpfile converter for 1.0.9->1.1.
  - The evaluation order of array and mapping aggregates is now left to right,
    because this is more intuitive.  From now on I'll consider the evalution
    order of aggregates and function arguments to be fixed, rather than
    undefined.
  - Added list of directly inherited objects to the control block.
  - Won't cause a fatal error on too small dynamic chunk anymore (just allocate
    the larger chunk).
  - Some Mac compatibility fixes.
  - Added T_RESERVED type for add-on packages.
  - Fixed character initializer tables.
  - Added keyword "atomic".
  - Got rid of C_LOCAL.
  - More Mac compatibility fixes.
  - Merged fcontrol.h with comp/control.h.
  - Removed "atomic" again.  One way or another, multitasking will wreak
    havoc with DGD's concept of data being local to objects (which is very
    important for efficient swapping).  Maybe in 2.0.
  - Reduced memory usage, at the cost of slightly slower string and array
    deletes.
  - Speeded up swapping of objects with a tangle of arrays and mappings.
  - Arrays that are shared between objects are now made unique in each object
    immediately after execution has completed, rather than at the moment when
    one of the objects is swapped out.
  - Fixed some remaining ANSI C incompatible prototypes <-> function
    declarations in the editor.
  - Fixed some bugs in the array exporting code.
  - And some more.
  - And some in the memory reduction changes as well.
  - get_dir(foo) will always treat foo as a pattern, even if there is a file
    with that name.
  - Generate a compile-time error for functions larger than 64K.  Programs can
    now be larger than 64K.
  - Compile-time checking for too many string constants or function calls.
    The number of arrays and string values in an object can be larger than
    65535.  Replaced longs by Uints in swapping functions.  Extended ref
    counts to Uint for swapped-out data.
  - Binary connections don't buffer anymore.  send_message() returns 1 if the
    write succeeded (always 1 for telnet connections), and 0 if the write
    failed.
  - Fixed a bug in the compiler that was exposed by the changes in the code
    generator.
  - Inheriting a renamed clone could cause trouble.
  - send_message() now returns the number of bytes written (1 for echo on/off)
    or 0 in case of an error.
  - Fixed a bug introduced in get_dir() in the latest rewrite.
  - Temporarily disabled new export code to track down bugs.
  - Fixed a tiny destructive bug in the swapping code, recently introduced.
  - 0.0 == 0 was 0, is now 1 (!0.0 already was that).  For all other value
    combinations, integers and floats remain different.
  - Re-enabled export code.
  - Allow any binary port value (telnet port remains >= 1024).
  - Function_object() won't find a static function in a different object anymore
    (because it cannot be called).
  - Smarter selection of objects for swapping.
  - Rebuilt the main loop so continuous exec cost errors during callouts don't
    result in user command starvation.
  - Ignore NUL characters in telnet input.
  - Fixed another array exporting bug.
  - foo() = bar; could crash the system.
  - An incomplete recovery from a syntax error during compilation of a switch
    statement could result in a crash.
  - Discarded I_PUSH_FLOAT2 and I_CALL_AFUNC in favor of I_CALL_IKFUNC and
    I_CALL_IDFUNC (needed for object upgrading).
  - Change of the version numbering scheme: rather than 1.0.9.24, the current
    version is 1.0.10.  The next major release is still 1.1.
  - Made value stack and call stack dynamically expandible.
  - Fixed several stack depth miscalculation bugs.
  - Added a cleanup function to the error context, used mainly to clean up
    the value stack in case of an error.
  - (int) "12a" now results in an error, as does (float) of the same.
  - Renamed "exec cost" to "ticks".
  - Replaced lock() with the following language construct:
 
     rlimits (stack; ticks) {
         /* statements */
     }
 
    This will execute code with reduced or increased stack depth and ticks.
    There are two new driver calls to handle it: at compile time, for each
    rlimits construct, driver->compile_rlimits(objectname) is called.  If this
    function returns non-zero, the rlimits is allowed without futher ado.  If
    it returns 0, then at runtime there will be an additional check,
    driver->runtime_rlimits(obj, stack, ticks).  If zero is returned from this
    function, an error results.  This allows fast execution of rlimits
    constructs in trusted code.  For precompiled code, the return value is
    always assumed to be 1 (!).
    By default, there are no resource limits.  Also, driver->log_error() is
    called without resource limits.
    -1 can be used in rlimits to signify that a resource should be unlimited.
  - Removed call_stack, value_stack, reserved_cstack, reserved_vstack and
    exec_cost from the config file.
  - Replaced max execution cost with remaining stack depth and remaining ticks
    in the array returned by status().
  - Removed kfun get_exec_cost().
  - Replaced driver->compile_log() with driver->compile_error(file, line, err).
    By default, DGD now writes nothing to stderr at all.
  - Renamed driver->log_error() to driver->runtime_error().
  - Fixed a bug in the new error cleanup code.
  - Fixed some rlimits bugs in the C code generator.
  - Fixed a nasty bug in the code generated for sscanf().
  - And another one, and another one in the error cleanup code as well.
  - Made it possible to use ( ) in inherit string expressions.
  - Fixed a bug in the C code generator; no check was made to see if the stack
    had been reallocated after a kfun- or function call.
  - Fixed a memory leak in get_dir(), also introduced in the latest rewrite.
  - Renamed all p_* prototype headers to pt_* in an attempt to avoid conflicts
    with existing library functions on some machines.
  - Binary connections: if send_message() cannot send a string in one go, it
    puts the remainder in a buffer which is emptied as soon as possible.  When
    all data is sent, message_done() is called in the user object (but only if
    the output could not be sent all at once).  Using send_message() while
    previous output is still unfinished will flush the buffer, and prevent
    message_done() from being called.
    Binary connections have 64K buffers which are allocated statically, so
    the static chunk should be large enough (70K or so).
  - Run callouts less often if they take more than half of the available time.
    May be useful for muds on extremely heavily loaded hosts.
  - After runtime_error() was called, no resource limits would be set.
  - Renamed path_ed_read() and path_ed_write() to path_read() and path_write(),
    respectively.
  - When the last reference to a program is removed, call
    driver->remove_program(objname).  The call is done with rlimits -1; -1 and
    errors will be caught and ignored.
  - Removed driver->path_object() and driver->compile_object().
  - Added kfun compile_object(name): compile the named object, which must not
    already exist.
  - clone_object() now takes a (master) object as an argument.
  - find_object() no longer calls driver->path_object() to translate a path.
  - call_other() now calls driver->call_object() to translate a string to an
    object.
  - Added list of precompiled objects to status().
  - Increased the number of different sized large free chunks the static memory
    manager can handle.
  - In connect.c, calls to accept() will now only be done if the controlling
    socket was marked for reading by select().
  - The object free list wasn't properly maintained anymore.
  - A cloned object erroneously didn't have its creator function called right
    away.
  - Replaced driver->path_inherit() by driver->inherit_program(), which must
    return an object (which may be compiled inside the function).
  - driver->inherit_program() was accidentally called when implicitly inheriting
    the auto object, too.
  - Added '^' to filename pattern matching (as in csh).
  - Fixed a problem with precompiling objects that inherited the auto object.
  - When restoring from a state dump, callouts in objects no longer need to
    be patched.
  - Added precompiled objects to the dumpfile (though nothing is done with them
    yet on restore).
  - 1.1 DUMPFILE FORMAT REACHED.  Up to the next major release, version 1.1,
    the dumpfile format will not change.
  - Made ticks a more reasonable measure.  In many cases it just reflects what
    I think something should take -- or what I want to make expensive.
    Currently, the editor still takes no ticks.
  - The object table wasn't properly prepared before including it in a state
    dump.
  - catch { stmts } is now allowed as a statement.
  - Fixed some bugs in the new catch code.
  - Fixed a long-standing but never before discovered problem with destructed
    objects as mapping indices.
  - The driver object can inherit the auto object again, and the auto object
    can use the rlimits statement without limitations.
  - If an error is caught internally, the proper error handler is called again.
  - Ported DGD to Windows 95/NT.  Left to do: starting by double-clicking a
    config file, program icons.
  - Disallowed #include from the config file, which would cause a crash.
  - Precompiler brought up to date with latest change in error handling.
  - Send IAC GA to all users with a prompt, not just the current user.
  - Swapping in an object with more than 127 inherits might result in a crash.
  - Precompiling still didn't work for objects with more than one level of
    inheritance.
  - Error recovery was incomplete in case of an error in sscanf() or in
    user->close().
  - Win32 version can now be started by double-clicking the config file.
  - Fixed a nasty error context bug.
  - Fixed a rare bug in string swapping.
  - user->close() now takes an integer argument, 1 if the connection is closed
    from the mudlib, 0 if it's due to linkdeath.
  - Made statedumps more efficient.
  - The static chunk size can now be 0, which has the effect of never causing
    an automatic swapout, at the cost of more memory fragmentation.
  - Made sure ctime() works, even if the host implementation cannot handle
    "negative" times.
  - Fixed a problem in the new statedump code, which might occur with frequent
    statedumps.
  - The priority queue for to be swapped-out objects now works better.
  - Merged in Mac compatibility fixes.
  - Discontinued support for MINIX_68K and ATARI_ST.
  - Fixed a bug in inherited function calls with very large function tables.
  - Fixed a bug which could result in connections being closed immediately,
    often occurring if connections were being opened and closed at a rapid
    rate.
  - Process termination is now done through driver->interrupt().  This
    function must exist and should minimally consist of
 
     void interrupt() { shutdown(); }
 
  - Fixed a problem with %% in a sscanf format string.
  - Fixed a potential crash if the stack array created in call_trace() was
    too big.
  - call_other(obj, "foo\0bar") could be used to call the function foo.
  - Binary connections now have output buffering in the user object, instead
    of a 64K static buffer.  User objects that are buffering will not
    normally be swapped out.  The input buffer size for a binary connection
    has been increased to 8K.
  - Made often-used objects less likely to be swapped out during a lull in
    activity.
  - With global typechecking, a function without declared type has type void.
  - Fixed some bugs in new output buffer handling.
  - During precompilation, inherit paths without a leading slash are now
    considered to be relative to the current directory, rather than absolute.
  - C code generated for >>= and <<= operators made more portable.
  - Disambiguated results of division and remainder operations.
  - No more core dumps for errors in the configuration phase.
  - PC version: don't exit program immediately on a configuration error when
    started without an argument.
  - Fixed a problem in precompiled code generated for catch { }.
  - Catch { code; } is now optionally followed by : { caught; }.
  - Functions without declared type were accidentally untypechecked, even with
    global typechecking enabled.
  - Made hashtables faster in some cases.
  - PC version: don't ask for confirmation if the program is stopped from the
    outside and was started with an argument, making it easier to run it as
    a service on NT.
  - Fixed a bug that made it possible to access files outside the mudlib
    directory on Win32.
  - Fixed a rare problem with arrays as mapping indices.
  - If the time was set back during callout processing, it was possible for
    the next callout never to be started.
  - Fixed a bad memory fragmentation problem in case a block of memory was
    allocated that was larger than the dynamic chunk.
  - DUMPFILE FORMAT CHANGED AGAIN.  This unfortunately became necessary because
    of missing information for dumped precompiled objects.  When the dumpfile
    format stabilizes again, it will be marked in this file.
  - restore_object() now does typechecking, if global typechecking is enabled.
  - Faster code with global typechecking.
  - Re-introduced keyword "atomic".
  - Extended precompiled function index from 2 to 3 bytes.
  - Accept binary connections more quickly.
  - Optimize generated code a little further, particularly generated C code.
  - Fixed possibly bad code generated for breaking out of a catch.
  - Fixed a problem with ellipsis in calls to functions without prototype.
  - Improved dead code removal.
  - Tweaked the last tweaks in generated C code optimization.
  - Bugfix in C code generated for ?:.
  - Attempt to avoid Linux bug in socket writes.
  - Generate better C code for calls to builtin kfuns.
  - Generate summand operators in more cases.  Also fixed a crashing bug in
    case all operands of a summand are 0.
  - Fixed a compiler bug which sometimes rejected x..x case label ranges.
  - Generate summand operators in even more cases, where array aggregates
    are now also included.
  - Added 2nd argument to driver->remove_program(), the compile time of the
    object.
  - Cleaned up comm.c a bit.
  - Made sector independent of uindex.
  - String constants are no longer shared between control block and dataspace
    when swapped out.
  - Objects can be recompiled before being destructed if they are not inherited.
    This has the effect of upgrading the object and all clones to the new
    program.  Variables with the same name and type (private and static don't
    matter) are preserved in the upgraded object; all other variables are
    initialized to 0.
  - Brought dump_function() up to date.
  - Fixed a nasty bug in the runtime support for precompiled code.
  - Some fixes for the order of events in the main loop, and telnet buffer
    flushing in comm.c.
  - Several bugs fixed in the recompiling code.
  - And some related ones.
  - And some more.
  - Array swapping and exporting made faster.
  - When an object is destructed, remove callouts immediately from the callout
    table.
  - Dumpfiles from different platforms are now converted at boot time.
  - Fixed a bug in restoring the swap header.
  - Generate a trace.h include file for call_trace() on startup.
  - Brought precompilation up to date with latest changes.
  - General code cleanup.
  - Fixed a nasty crasher in endthread() with the help of Sieni@Muhveli.
  - Fixed a problem with destructed objects as mapping indices.
  - Optimized communications handling and get_dir().
  - Fixed memory leak in generated C code.
  - Made the maximum string size the same on all hosts and removed
    MAX_ARRAY_SIZE and MAX_MAPPING_SIZE from limits.h (status()[ST_ARRAYSIZE]
    should be used).
  - If select() is interrupted, make sure that all socket read flags are zero.
  - DUMPFILE FORMAT STABLE AGAIN, and it had better not change before 1.1...
  - Added 3rd argument to runtime_error(), ticks left, and removed ST_ASTACKDEPTH
    and ST_ATICKS.
  - Patterns in get_dir() accidentally matched almost anything.
  - Several mapping problems fixed.
  - Added kfun previous_program().
  - The start time was not restored properly.
  - Made callouts more accurate when time() is used for timing, at the cost of
    an extra system call for each new callout.
  - Fixed a bug in restoring a sector map that didn't fit in one sector.
  - Fixed an ancient bug in #if expressions.
  - Can't use \0 in kfun file name argument anymore.
  - Let status(obj) give updated information about objects recompiled during the
    current thread.
  - Make more of an effort to buffer telnet output if all of it could not be
    sent right away, making sure that no telnet escape sequences are sent only
    partially.
  - Fixed a bug occurring when objects are upgraded and destructed in the
    same thread.
  - __FILE__ did not include a leading /.
  - Some other upgrade-related bugs fixed.
  - Fixed bug which would occur with foo() { return catch("bar"); }
  - Setting a variable didn't work in the editor.
  - Initial Mac port completed.
  - Split up comm initialization in two parts, one for general initialization
    and one to start listening on the ports.
  - Fixed a bad bug in the code generated for a return out of a catch { }.
    Unfortunately, the fix affects the code generated for all catches, making
    older state dump files INCOMPATIBLE.  It is possible to convert an old
    dumpfile if all objects in it are upgraded, and if the objects that perform
    the upgrade have no catch or are precompiled.
  - return val; was typechecked only at compile time, not at runtime.
  - Fixed some bugs in the Mac port.
  - Make sure all connections are closed as soon as it is known that the
    system is shutting down, instead of waiting until after a state dump.
  - Fixed a loss-of-variable bug in upgrading while restoring state.
  - Enabled edit menu in Mac port.
  - Precompiled objects now replace existing objects silently, rather than
    causing an upgrade.  The object replaced must have the same inherit,
    string, function definition, variable definition and function call tables.
    NOTE: the dumpfile format was slightly changed, but state dumps that do
    not contain precompiled objects are unaffected.
  - Added a new status(obj) field, the "index" of the master object (the
    object itself unless it's a clone).  This is a unique ID, and will help
    distinguishing different issues of the same object, and linking clones
    to a particular issue.
  - Added third argument to driver->remove_program(), the "index" of the
    object.
  - Made DGD compile on SunOS 5.5, too.
  - Fixed a bug in precompiled code generated for sscanf().
  - Fixed a stack depth miscalculation bug in the optimizer.
  - Removed >= 1024 limitation on telnet_port (makes no sense on non-unix
    machines).
  - Error messages in restore_object() were accidentally too terse.
  - Improved some other error messages.
  - Using more than 7 indirection stars now results in an error.
  - Optimize `1 && a' and `0 || a' to `!!a', rather than `a'.
  - Fixed a bug in upgrading an old clone after doing a recompile on the object
    earlier in the same thread.
  - Corrected some floating point rounding errors.
  - The return value of a redirectable function was not properly checked in
    a call from an untypechecked function.
  - Added mapping subranges.
  - Made dealing with destructed objects in arrays and mappings faster.
  - Prevent the compiler from attempting to compile foo.c directories.
  - Fixed a bug in multi-phase upgrading of an old clone.
  - Perform swapout, state dump and shutdown immediately upon completion of
    the thread in which they are initiated.
  - Worked around the latest Visual C++ bugs.
  - Changed the meaning of O_DATASIZE in status(obj): this now returns the
    number of variables, rather than the assumed amount of space they take.
  - Deal with the auto object possibly being upgraded while inherited.
  - Fixed a <very> rare bug that might occur when objects are used as mapping
    indices.
  - Made map_sizeof() a cheaper operation.
  - PC version: enabled the edit menu.
 
  DGD 1.2
 
  - Added swapfile compression.
  - Fixed a stack depth miscalculation bug.
  - Generate recognizable function names for precompiled functions.
  - Speeded up a few functions highlighted by gprof.
  - Removed some old compatibility code from the editor.
  - Increased max string length in status() to 65535.
  - Increased max editor output string length to 65535.
  - Made DGD restartable.
  - Fixed a line range bug in editor global commands.
  - Fixed a bug/typo in object upgrading.
  - Fixed a bug in exporting mappings.
  - Made compression a bit faster.
  - Fixed the exporting bug fix.
  - Use SO_OOBINLINE on sockets if the host supports it.
  - Clear update field in all objects after a restore.
  - Compensated for a bug in ctime() on some unices.
  - Removed many references to global variables.
  - Removed some code from the upgrading procedure that was unreachable.
  - Improved Mac edit menu.
  - Avoid swapping in needlessly while writing partial sectors.
  - Zero unused sector parts to make swapfiles more compressible.
  - Sped up sector allocation and removal, and fixed a bug introduced in the
    partial sector write patch.
  - The wrong stack depth was passed on to driver->runtime_error() if the
    the server used an internal catch.
  - Added a new kfun, block_input().
  - Fixed a leftover bug in the swapping changes that made reclaiming of freed
    sectors unlikely, and a crash possible just after a successful state dump
    had been made.
  - Read_file() was returning 0 in an error situation, and also when it
    should return "".
  - Fixed a memory leak introduced in the global variable rewrite.
  - Made editor code reentrant.
  - Callouts with a delay of 0 seconds are now executed as soon as possible.
  - Sort callouts in status(obj) by handle rather than by delay, as no actual
    calling order for same-delay callouts can be guaranteed.
  - Deal more efficiently with blocked connections.  Also don't close a
    connection while there is still input to process.
  - Optimize indexing the value returned by kernel functions: status()[i],
    status(obj)[i], call_trace()[i].
  - The value of integer arguments in precompiled functions would not always
    be given correctly in call_trace().
  - String range problems at compile time now result in a proper compile-time
    error again.
  - Make a = ({ "asd" }); a[0][1] |= 7; work correctly again.
  - Fixed a severe bug in the code generator that could, under some
    circumstances, lead to else statements also being executed when only
    the if statement should have been.
  - Fixed a bad bug in global float variable initialisation, reported by
    Azhrarn@Flat Earth.
  - In case of an error during inheritance, the name of the relevant object
    was not properly saved.
  - Compensate for the latest (post 5.0) Visual C++ problem.
  - Partial parse_string implementation.  Currently only does lexical scanning,
    and returns an array of tokens.  Only Unix makefiles have been adjusted yet.
  - Fixed some Mac compilation problems for various compilers.
  - Replaced some FREE,ALLOC pairs with REALLOC.
  - Completed parse_string implementation on all platforms.
  - Fixed a bug that prevented any restore from dump file.
  - Fixed a bug in REALLOC.
  - And some more.
  - Fixed two (crashing) bugs in parse_string.
  - And a third.
  - New kfuns: query_ip_name(), send_datagram() (at present for Unix only).
  - DGD ported to BeOS.
  - Fixed a crashing bug in alternative parse tree handling.
  - Get the precompiler to compile again (after the last kfun additions).
  - Fixed a bug in parse_string() that prevented proper compression of the
    shift/reduce parser, and could also lead to strings being erroneously
    rejected.
  - Let status() report the proper program size, even if the object is swapped
    out and compressed.
  - Increased max number of function parameters + local variables to 255.
  - Fixed a stack depth miscalculation bug for untypechecked code.
  - Generate a proper compile-time error if a string constant is indexed by
    an integer that is out of range.
  - Allow datagrams of length 0.
  - Ported query_ip_name() and send_datagram() to Mac and Win32.
  - Improved tick counting and check for overflows in parse_string().
  - Max number of function parameters + local variables reduced to 127, the
    interpreter cannot actually handle more than that many.
  - Removed static variables from all over.  Only the unix versions will
    compile at present.
  - Code cleanup made assignments slightly faster, at the cost of somewhat slower
    swapping.
  - Fixed a bug that could cause wrong assignments to indexed arrays in sscanf().
  - Avoided the nasty gethostbyname() problem on Windows 95.
  - Fixed a compiler typechecking bug for (mixed - array).
  - Fixed a crashing bug that occurs when an object has more callouts than
    the maximum array size.
  - Fixed a spurious inherited function clash in multiple inheritance.
  - Added private inheritance.
  - Avoided the use of gethostbyname() on BeOS for similar reasons as on Win95.
  - Non-unix versions compile again.
  - Fixed a float testing bug in precompiled code.
  - Fixed a bug in array exporting, introduced in the last assignment/swapping
    rewrite.
  - Fixed the bug in the fix.
  - Added the constant `nil'.  If typechecking is 0 or 1 (in the config file),
    nil has the value 0.  If typechecking has the value 2, nil is distinct from
    integer zero.
    String, object, array and mapping variables are initialized to nil.  Using
    call_other() to call a non-existant function returns nil.  Variables holding
    an object become nil after the object has been destructed.  Indexing a
    mapping with a non-existant index results in nil, and nil must be assigned
    to delete an index:value pair; assigning 0 has the same effect only when
    0 and nil are the same.
  - allocate() now allocates an array of nil values.  New kfuns allocate_int()
    and allocate_float() explicitly allocate arrays of those respective values.
  - In a further bit of type matching cleanup, integer 0 and floating point 0.0
    no longer test as equal.
  - Merged T_NIL with T_INVALID internally.
  - It is now possible to use varargs in a parameter list to specify that only
    the following parameters are optional:
 
         void foo(int a, varargs string b, object c)
         {
         }
 
    In typechecking mode 2, this is the only way that varargs can be used.  It
    is an error to call a function with too many or too few arguments, even when
    using call_other() (typechecking mode 2 only).
    Varargs is implied for the last parameter when using ellipsis, and need no
    longer be specified explicitly.
  - Changed over kfuns to the new varargs system.
  - Removed some kfun argument count checks that have become superfluous.
  - New variables in upgraded objects were initialized with integer 0 rather
    than nil.
  - Let send_message() and message_done() behave in the same way for telnet and
    binary connections.  send_message() now never returns -1.
  - Allow callouts with millisecond delays (floating point delay argument).
  - Process a for loop in the same order in codegenc.c as in codegeni.c (body
    first, then condition), to ensure that tables are generated in the same
    order by both.
  - Math functions implemented.
  - New kfun millitime (was added before, but not mentioned in the log).
  - Made behaviour of << and >> uniform on all platforms: no negative shift
    allowed, shifts >= 32 make the result 0.
  - Check that a switch doesn't contain more than 32767 cases, and a function
    doesn't need more than 32767 values on the stack.
  - Put automatic object swapping, accidentally left out in the callout rewrite,
    back in.  NOTE: one out of every swap_fragment objects is now swapped out
    at the end of each thread, rather than each second.  This means that to get
    the same memory usage, the swap_fragment parameter should get a
    considerably larger value.
  - Simplified the automatic object swapping; too much was happening at the
    end of each thread, especially with many objects in memory.
  - Show which function is actually being called with too many or too few
    arguments.
  - Fixed a bug which could mess up the callout table when making a state dump.
  - Fixed a bug in the configuration phase which mysteriously escaped notice
    until now.
  - Guard against too deep recursion in the editor.
  - When upgrading, don't wipe out variables that change type to mixed.
  - Make extra-sure that sockets under Windows and BeOS are non-blocking.
  - Fix a bug in calling LPC code from the string parser.
  - parse_string() traversed alternatives even when it didn't have to.
  - String case labels with embedded NUL characters were not compared properly.
  - Fixed a tricky bug in swapping out mappings with object indices that have
    been destructed and replaced by a new version with the same object index,
    that had eluded me for a long time.
  - Return value of remove_call_out() was incorrect if callout didn't exist or
    had millisecond delay.
  - Slightly better indexing of mapping with string.
  - Removed recursion limit on catch and rlimits.
  - Fixed a file descriptor leak in P_readdir() for Windows.
  - Fixed a crash in the first uncaught error.  Whoops.
  - Last batch of changes before atomic.
  - There is no need to use static, nomask or atomic in prototypes anymore.
    However, if any of these are specified, they must also be present in the
    actual function declaration.
  - Partial implementation of atomic functions.
  - Forbid file changes in atomically executed code.
  - Fixed a slew of bugs in atomic functions.
  - In case of an error in atomic code, call driver->atomic_error() with the
    full stack trace.  Everything will be undone later, except for all use of
    send_message() by the driver object.
  - ctime() didn't give the proper weekday for times > 0x7fffffff.
  - If there is no more input on a connection, make sure there is no pending
    output before closing it.
  - Temporarily disable compile_object(), clone_object(), destruct_object(),
    call_out() and remove_call_out() from within atomic code, making atomic safe
    to use.
  - Connections with pending output that failed in a write would never get
    closed.
  - Newly added mixed variables would get the value of the old variable in the
    same slot during upgrading.
  - Adjust precompiler to latest changes in callout interface.
  - Get DGD on BeOS to compile again.
  - Fix a bug in name lookup which could hang the server.
  - Use a Windows font that displays properly on foreign language systems.
  - Only commit changes to a previous plane if there <is> a previous plane.
  - Fixed a bug in atomic code when swapout is involved.
  - The editor now shows characters in range 0x80 - 0x9f normally.
  - Fixed some more bugs in the name lookup code.
  - Encapsulate creation of values with macros, making it easier to extend the
    value struct.
  - String constants for string switches were generated in the wrong order.
  - Completed callout undo (atomic functions).
  - Fixed a reference counting bug in callout undo.
  - Replaced many direct object references with indirect ones.
  - Fixed yet another bug in the name lookup code.
  - Fixed a old and very rare bug in mapping addition.
  - New kfuns hash_crc16(), hash_md5().
  - Fix a recently-introduced bug in clone upgrading.
  - Fix a bug in callouts with more than 3 extra arguments, introduced with
    callout undo.
  - Fixed a bug in compiling an object that redefined a privately inherited
    function.
  - Prevent a crash when space for the restoring of a huge save file cannot be
    allocated on the stack.
  - Fixed two more bugs in atomic commit code.
  - Allow the internal state machines for parse_string() to become larger than
    before.
  - Fixed the Windows quit/interrupt bug.
  - Fixed a bug that was introduced into parse_string().
  - Undid an overeager optimization in parse_string().
  - Fixed a string accounting bug in atomic code.
  - Fixed several hard-to-trigger bugs in object upgrading.
  - Fixed another private inheritance bug.
  - Completed object undo (atomic functions).
    WARNING: before starting to use 1.1.97 with a statedump from a previous
    version, make sure there are no un-upgraded clones left in the statedump.
    This can be done by rebooting an additional time with the previous driver
    version, and immediately shutting down again with a statedump.
  - Fixed an object undo bug.
  - Completed comm undo -- and the implementation of atomic functions.
  - Fixed a bug in users().
  - Made the type of a variable that holds the number of simultaneous users
    configurable.
  - Let the DNS thread be started only once, even for several driver process
    runs.
  - Fixed some more comm bugs.
  - Fixed a bug that could lead to random stack overflow errors.
  - Made room for another type of special object.
  - Made maximum sizes of strings more configurable.
  - Allow any string as an argument to error().
  - Fixed some leftover short string holdouts.
  - Got precompiling to work again; add global variable and function names to
    generated C output.
  - Make sure the error context is cleared at the proper time.
  - Fixed another object undo bug.
  - Completed the string accounting bug fix; the earlier fix was only partial.
  - Fixed the above for the case of multi-level atomic calls.
  - Fixed a restore-time bug involving upgraded objects.
  - Fixed a bug in removing dataspaces.
  - Allow only one simultaneous new editor instance per thread.
  - Fixed a bug where a connection would hang if there was pending output while
    the connection was lost.
  - Remove the swapfile before creating it, to make sure that two drivers
    attempting to use the same swapfile won't mess it up for both of them.
  - Fixed yet another object undo bug.
  - Undid some telnet input processing modifications, since any change in this
    code will only further confuse client programs.
  - Fixed a bug in atomic commit for exported arrays.
  - Fixed a bug in restoring a parser state machine.
  - Fixed a reference counting problem in the atomic array code.
  - Fixed a bug which could cause an infinite loop in flushing socket output.
  - The arguments of callouts were not properly committed to the base plane.
  - Removed some global variable dependencies from swapping and exporting.
  - Make sure that there is room for a new object when compiling.
  - Callouts were not properly committed to planes above the base plane, either.
  - Made the number of swap sectors to be reconstructed in the main loop
    configurable.
  - Exported arrays could be committed to the wrong plane.
  - Inheritance of objects that inherit destructed objects was not always
    checked at the right time.
  - Make sure that a disconnected socket with pending output is closed.
  - Fixed an object undo bug that could happen if an object was created and
    destructed on the same discarded plane.
  - Fixed a minor memory leak in comm.c.
  - Runtime_error() would erroneously not be called on an error during mudlib
    initialization.
  - Got the precompiler to work again.
  - Got the editor to work properly on MacOS and Windows.
  - Changed some fatal errors into configuration errors.
  - Do not allow a restart after a fatal error.
  - Removed support for stand-alone compilations of editor and lexical scanner.
  - Implemented DGD runtime extension interface.
  - Fixed another tricky bug that could commit arrays to the wrong plane.
  - Even trickier than I thought.
  - Make sure the return value of an atomic function is on the proper plane.
  - Better fix for the above.
  - Rebuild the swapfile slowly, even if there is no socket and/or callout
    activity.
  - Fixed the quit/interrupt problem on BeOS.
  - Finally fixed the DST time-jumping problem on Windows.
  - Get the Mac version to compile with OLDROUTINENAMES=0.
  - Some more Mac fixes.
  - If an IP name query for an IP number failed once, it would erroneously not
    be re-requested as long as it was still in the cache.
  - Start with fixed window size on Windows.
  - Fixed a bug in committing plane n, and then discarding plane n-1.
  - Fixed a memory leak in committing a mapping that has been reduced in size.
  - Fixed the comm code, which erroneously assumed that nothing new would be
    sent on a connection after the connection object was destructed.
 
 DGD 1.2p1
 
  - Destructed objects in arrays were not always dealt with properly after the
    introduction of atomic functions.
  - Replacing interpreted objects with precompiled ones at restore time failed
    to work properly.
  - remove_call_out() would not always return the correct remaining time.
  - Return the correct time in the per-object list of callouts, also.
  - Destructing and then recompiling an object within the same thread could lead
    to trouble.
  - Fixed some typos in dgd_ext.h.
  - Fixed a hanging-connection bug in comm.c.
  - Don't allow "..." as a path component in Windows.
  - Fixed a bug in recompiling an object that indirectly inherits a privately
    inherited other object.
  - Fixed a find_object() bug in atomic code.
  - Fixed a bug that caused swap sectors to be freed at the wrong moment during
    a restore.
  - Inheriting an object both privately and non-privately could prevent
    functions from being found.
  - Under some circumstances, the call to message_done() would be delayed until
    the next callout, or until more user input was received.
  - Unix: make sure that a debugger won't interfere with the name lookup process.
  - Fixed a crashing bug in the compiler for a switch that contains only a
    default label.
  - Arrays saved with save_object() should save object values as nil, not 0.
  - Fixed the too-many-callouts check, which has been completely wrong since the
    introduction of atomic functions.
  - Fixed some more bugs in callouts, such as a possible crash when removing a
    callout with millisecond delay.
  - Fixed a tricky left-over version of the aforementioned bug.
  - Fixed the above fix.
  - Show a proper errormessage if precompiling fails.
  - More helpful errormessages when casting a string to float or int fails.
  - %f in a sscanf format strimg would match the empty string.
  - Fixed a bug in the pow() function.
  - Fixed a bug in calculating line numbers in a stack trace.
  - Fixed a stack depth miscalculation bug for subranges.
  - Fixed some bugs in the extension interface.
  - Fixed a precompiled object restoring bug.
  - Fixed a minor bug in restoring the parser state machine.
 
 DGD 1.2p2
 
  - The editor could erroneously allocate dynamic instead of static memory.
  - Fixed a spurious pause that would occur if the first callout started after a
    cold boot had a delay of 0.
  - Fixed a problem with repeatedly adding and removing callouts in atomically
    executed code.
  - Fixed several bugs in error handling.
  - A better fix for errors in atomic code, in combination with multi-level
    catches.
  - Fixed a config file reading bug that could occur if the server was restarted.
  - Fixed a bug in saving/restoring variables in an object that privately
    inherited another.
  - Prevent code from being erroneously optimized away in rare cases.
  - Fixed a bug in handling some regular expressions.
  - Fixed several bugs which could, in rare cases, cause nil to turn up in
    mappings that had been accessed from atomically executed code.
  - Fixed a bug in error recovery for compiling switch statements.
 
 DGD 1.2p3
 
  - Fixed a bug that could occur when upgrading an interpreted object to
    precompiled.
  - Fixed a bug with catch and atomic in precompiled code.
  - Fixed a recursion problem for an error in runtime_error().
  - Better fix for the callout pause problem.
 
 DGD 1.2p4
 
  - Fixed a bug with deleting mapping elements in atomic code.
  - Allow allocation of blocks up to 1G in size.
  - Fixed a bug that could cause a crash during the atomic commit phase.
  - While restoring a callout, not all appropriate fields were zeroed.
  - Some fixes to get restarting to work.
  - Make sure that a callout handle is not truncated to 16 bits before an
    attempt is made to remove it.
  - Made sure that destructing the driver object in atomic code does not lead
    to trouble.
  - Fixed a problem with driver->recompile() in multi-level atomic code.
  - Input blocking for binary connections didn't work.