X-Git-Url: https://jxself.org/git/?p=open-adventure.git;a=blobdiff_plain;f=notes.adoc;h=884d1ce7f7d5ff970e2ca331687afe5e17cffe67;hp=c41a5b645c69683b7a54133e32602d629e38d336;hb=f815299a2a97656b0f4ea0793c2207c2437888f6;hpb=9e08cba63e45ed056b2c400435ba210ccb2c091f

diff --git a/notes.adoc b/notes.adoc
index c41a5b6..884d1ce 100644
--- a/notes.adoc
+++ b/notes.adoc
@@ -10,8 +10,9 @@ separate link:history.html[history] describing how it came to us.
 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 assistance
-of Peje Nilson in restructuring some particularly grotty gotos is
-gratefully acknowledged.
+of Peje Nilsson in restructuring some particularly grotty gotos is
+gratefully acknowledged. Petr Voropaev contributed fuzz testing. Aaron
+Traas did a lot of painstaking work to improve test coverage.
 
 == Nomenclature ==
 
@@ -60,16 +61,21 @@ Using "seed" and -l, the distribution now includes a regression-test
 suite for the game.  Any log captured with -l (and thus containing
 a "seed" command) will replay reliably, including random events.
 
-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.
+The adventure.text file is no longer required at runtime.  Instead, an
+adventure.yaml file is compiled at build time to a source module
+containing C structures, which is then linked to the advent
+binary.  The YAML is drastically easier to read and edit than
+the old ad-hoc format of adventure.txt.
 
-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.
+
+A -r command-line been added. When it is given (with a file path
+argument) it is functionally equivalent to a RESTORE command.
 
 == Translation ==
 
@@ -79,13 +85,19 @@ ugly and quite unreadable.
 
 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 now have over 95% coverage, with the remaining
+confined to exception cases that are very difficult to reach). This is
+what you are running when you do "make check".
+
+In the process we found and fixed a few minor bugs. Most notably, reading
+the relocated Witt's End sign in the endgame didn't work. Behavior when
+saying the giant's magic words outside his room wasn't quite right either.
 
-This move entailed some structural changes.  The most important was
-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.
+The move to modern C entailed some structural changes.  The most
+important was 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.
 
 The original code was greatly complicated by a kind of bit-packing
 that was performed because the FORTRAN it was written in had no string
@@ -96,12 +108,17 @@ of sixbit code points in a restricted character set, packed 5 to a
 verb was one of these words, and what would be string operations in a
 more recent language were all done on sequences of these words.
 
-We are still in the process of removing all this bit-packing cruft
-in favor of proper C strings.  C strings may be a weak and leaky
-abstraction, but this is one of the rare cases in which they are
-an obvious improvement over what they're displacing... 
+We have removed all this bit-packing cruft in favor of proper C
+strings.  C strings may be a weak and leaky 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
+We have also conducted extensive fuzz testing on the game using
+afl (American Fuzzy Lop).  We've found and fixed some crashers in
+our new code (which occasionally uses malloc(3)), but none as yet
+in Don's old code (which didn't).
+
+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
@@ -110,10 +127,9 @@ ways:
   and the choice to refrain will make forward translation into future
   languages easier.
 
-* There are some gotos left that resist restructuring; all of these
-  are in the principal command interpreter function implementing its
-  state machine.  One other left in the player-movement code, a two-level
-  loop breakout, is not reducible even in principle.
+* There are a few gotos left that resist restructuring; all 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
@@ -121,11 +137,18 @@ ways:
   to fix it because doing so would (a) be quite difficult, and (b)
   compromise forward-portability to other languages.
 
-* The code still has an unfortunately high density of magic numbers - in
-  particular, numeric object and room IDs.
+* Much of the code still assumes one-origin array indexing.  Thus,
+  arrays are a cell larger than they strictly need to be and cell 0 is
+  unused.
 
 * 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.
 
+We have made exactly one minor architectural change.  In addition to the
+old code's per-object state-description messages, we now have a per-object
+message series for state *changes*.  This makes it possible to pull a fair
+amount of test out of the arbitrary-messages list and associate those
+mesages with the objects that conceptually own them.
+
 // end