X-Git-Url: https://jxself.org/git/?p=open-adventure.git;a=blobdiff_plain;f=notes.adoc;h=cc4246c440abadd0b4b0605988261214a9e2ba3a;hp=4e110512da483d01f84937d3d9bcb3a4b4e686c5;hb=60126c3dac4788cd5c01f5da6bb50986aeaac0d3;hpb=3bdab31a0d0c8c7397be835cf97bbf4d5a1c97de diff --git a/notes.adoc b/notes.adoc index 4e11051..cc4246c 100644 --- a/notes.adoc +++ b/notes.adoc @@ -9,7 +9,9 @@ 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 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 == @@ -60,14 +62,16 @@ 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. +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 == @@ -77,11 +81,13 @@ 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 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 355 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. @@ -99,7 +105,7 @@ 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 +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 @@ -107,11 +113,9 @@ ways: 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 19 gotos left that resist restructuring; all 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 @@ -120,7 +124,9 @@ ways: 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