The principal maintainers of this code are Eric S. Raymond and Jason
Ninneman. Eric received Don Woods's encouragement to update and ship
-the game; Jason signed on early in the process to help.
+the game; Jason signed on early in the process to help. The assistance
+of Peje Nilsson in restructuring some particularly grotty gotos is
+gratefully acknowledged.
== Nomenclature ==
The adventure.text file is no longer required at runtime. Instead, it
is compiled at build time to a source module containing C structures,
-which is then linked to the advent binary.
+which is then linked to the advent binary. There is an adventure.yaml file
+as well; this is also compiled to C code, and will eventually replace
+adventure.text altogether.
-The game-save format has changed. This was done to simplify
-FORTRAN-derived code that formerly implemented these functions;
-without C's fread(3)/fwrite() and structs it was necessarily pretty
-ugly by modern standards. Encryption and checksumming have been
-discarded - it's pointless to try tamper-proofing saves when everyone
-has the source code.
+The game-save format has changed. This was done to simplify the
+FORTRAN-derived code that formerly implemented the save/restore
+functions; without C's fread(3)/fwrite() and structs it was
+necessarily pretty ugly by modern standards. Encryption and
+checksumming have been discarded - it's pointless to try
+tamper-proofing saves when everyone has the source code.
== Translation ==
Jason Ninneman and I have moved it to what is almost, but not quite,
idiomatic modern C. We refactored the right way, checking correctness
-against a comprehesive test suite that we built first and verified with
-coverage tools. This is what you are running when you do "make check".
+against a comprehensive test suite that we built first and verified
+with coverage tools (we have 88% coverage, with the remaining 12%
+confined to exception cases that are difficult to reach). This is
+what you are running when you do "make check".
This move entailed some structural changes. The most important was
-the refactoring of 354 gotos into if/loop/break structures. We
+the refactoring of over 350 gotos into if/loop/break structures. We
also abolished almost all shared globals; the main one left is a
struct holding the game's saveable/restorable state.
abstraction, but this is one of the rare cases in which they are
an obvious improvement over what they're displacing...
-The code falls a short of being fully modern C in the following
+The code falls short of being fully modern C in the following
ways:
* We have not attempted to translate the old code to pointer-based
We don't need whatever minor performance gains this might collect,
and the choice to refrain will make forward translation into future
languages easier.
-
-* There are 20 gotos left that resist restructuring; all but one of
- these are in the principal command interpreter function implementing
- its state machine. A 21st, a two-level loop breakout, is not reducible
- even in principle.
+* There are a few gotos left that resist restructuring; all of these
+ are in the principal command interpreter function implementing its
+ state machine.
* Linked lists (for objects at a location) are implemented using an array
of link indices. This is a surviving FORTRANism that is quite unlike
compromise forward-portability to other languages.
* The code still has an unfortunately high density of magic numbers - in
- particular, numeric object and room IDs.
+ particular, numeric object and room IDs. There are plans to fix this.
+
+* Much of the code still uses FORTRAN-style uppercase names.
+
+* The code is still mostly typeless, slinging around machine longs
+ like a FORTRAN or BCPL program. Some (incomplete) effort has been made
+ to introduce semantic types.
// end
projects / open-adventure.git / blobdiff