Loads thing templates from content/things/ at startup. Registers
get/drop/inventory commands via things module import. Reconstructs
player inventory from saved template names on login, with graceful
fallback for unknown templates.
Inventory saved as JSON list of thing template names in an inventory
column. Migration adds column to existing databases. load_player_data
returns inventory list, save_player serializes Thing names from contents.
ThingTemplate dataclass mirrors MobTemplate pattern. load_thing_template
and load_thing_templates parse TOML files from content/things/. spawn_thing
creates Thing instances from templates. Includes rock and fountain examples.
Object.move_to() handles containment transfer: removes from old location's
contents, updates location pointer and coordinates, adds to new location.
get/drop commands use move_to to transfer Things between zone and inventory.
Supports name and alias matching for item lookup.
Thing is an Object subclass with description, portable flag, and aliases.
Entity.can_accept() returns True for portable Things, enabling the
containment model where entities carry items in their contents.
Removes dependency on global players dict for spatial queries by using
Zone.contents_at() for spectator lookup. Makes _world local to run_server()
since it's only used during initialization to create the overworld Zone.
Updates test fixtures to provide zones for spatial query tests.
- Removed world module-level variable from look.py
- look.cmd_look() now uses player.location.get_viewport() instead of world.get_viewport()
- look.cmd_look() uses zone.contents_near() to find nearby entities instead of iterating global players/mobs lists
- Wrapping calculations use zone.width/height/toroidal instead of world properties
- Added type check for player.location being a Zone instance
- Removed look.world injection from server.py
- Updated all tests to remove look.world injection
- spawn_mob() and combat commands also migrated to use Zone (player.location)
- Removed orphaned code from test_mob_ai.py and test_variant_prefix.py
Adds zone_name field to PlayerData and accounts table to track which
zone a player is in. Defaults to 'overworld'. Includes migration logic
to handle existing databases without the column. Server now resolves
zone from zone_name when loading player data.
Removed module-level world variable and replaced all world.wrap() calls
with player.location.wrap(). Added Zone assertion for type safety,
matching the pattern in movement.py. Updated tests to remove fly.world
injection since it's no longer needed.
Movement commands now access the zone through player.location instead of
a module-level world variable. send_nearby_message uses
zone.contents_near() to find nearby entities, eliminating the need for
the global players dict and manual distance calculations.
Tests updated to create zones and add entities via location assignment.
Zone(Object) is a spatial area with a terrain grid. Supports
toroidal wrapping and bounded clamping, passability checks,
viewport extraction, and contents_at(x, y) spatial queries.
Zones are top-level containers (location=None) that accept
everything via can_accept().
Entity gains location from Object and narrows x/y back to int
(entities always have spatial coordinates). No behavioral change —
all existing tests pass unchanged.
Object provides name, location, x/y, contents reverse-lookup, and
can_accept() — the foundation for the containment tree that zones,
things, and inventory will build on.
Per the Z-machine spec, object 0 means "nothing" and operations on it
should be safe no-ops: get_child/get_sibling/get_parent return 0,
test_attr returns false, set/clear_attr are no-ops, etc. Previously
these threw ZObjectIllegalObjectNumber, crashing on games like Curses
that pass object 0 to get_child during room transitions.
step_fast() never recorded trace entries, so crash dumps always showed
an empty trace. Now records PC + opcode info in the same deque as
step(). Also includes exception type in player-facing error messages
when the exception string is empty.
MudInputStream.read_char() returned 0 for empty input, which no game
recognizes as a valid keypress. Now returns 13 (Enter/Return) so
"press any key" prompts like Curses' intro work from a MUD client.
The chunk module was deprecated in 3.11 and removed in 3.13.
Our usage was minimal (read name, size, data, skip padding),
so a small _read_iff_chunk() helper replaces it with no deps.
ZStackBottom already had stack and local_vars for uniform treatment,
but was missing return_addr. Adding it removes 5 type: ignore
suppressions and fixes all ty possibly-missing-attribute warnings.
Add step_fast() that skips trace/logging overhead (saves ~22% at 1M+
avoided log calls). Pre-resolve opcode dispatch table at init to
eliminate per-instruction version checks and isinstance calls. Replace
BitField allocations with direct bit masks in opcode decoder.
Cold start: 4720ms -> 786ms. Steady state: ~500ms -> ~460ms.
V5+ games write room names to the upper window (status line) via
select_window(1). Since select_window was a no-op, status line text
leaked into the main output buffer, causing ">Outside" on prompt lines.
Track the active window and only buffer writes to window 0 (lower).
- op_save_v5: generates Quetzal save, stores 1 on success / 0 on failure
- op_restore_v5: loads Quetzal save, stores 2 ("restored") via store byte
- _try_restore: detect V5+ in-game saves (0xBE 0x00 before PC) and process
the store byte with result 2, matching the V3 branch-on-restore pattern
- _find_story() now compares path.stem.lower() so "lostpig" matches "LostPig.z8"
- Server no longer writes its own prompt in IF mode (game handles prompting)
- Suppress phantom game output on restore (saved PC past sread causes garbage)
- Route .z5/.z8 files to EmbeddedIFSession now that V5+ is supported
Implements the opcode set needed for Lost Pig (V8):
- op_aread: V5+ input with text at byte 2, char count at byte 1,
stores terminating character
- op_save_undo/op_restore_undo: stub returning -1/0 (undo not yet
available, game continues without it)
- op_log_shift/op_art_shift: logical and arithmetic bit shifts
- op_scan_table: table search with configurable entry size and
word/byte comparison
- op_tokenize: re-tokenize text buffer against dictionary
- op_copy_table: memory copy/zero with forward/backward support
- op_set_font: returns 1 for font 1, 0 for others
- op_print_unicode/op_check_unicode: basic Unicode output support
Lost Pig now runs to completion: 101K steps, 61 unique opcodes,
3 full input cycles with room descriptions rendering correctly.
New opcodes: op_call_vn, op_call_vn2, op_call_vs2, op_catch,
op_check_arg_count. All call variants delegate to existing _call().
ZRoutine now tracks arg_count for check_arg_count.
Fixed zopdecoder double-byte operand parsing for call_vs2/call_vn2:
the old code called _parse_operands_byte() twice, but this method
reads both type byte AND operands together. The second call would
read operand data as a type byte. Refactored into _read_type_byte()
+ _parse_operand_list() so both type bytes are read before any
operand data.
Also fixed the double-byte detection: was checking opcode[0:7] (7
bits = 0x7A for call_vn2) instead of opcode_num (5 bits = 0x1A).
The check never matched, so double-byte opcodes were always
mis-parsed.
The old code inserted the object into the new parent first, then
tried to remove it from the old parent. This corrupted the sibling
chain because the object's sibling pointer was already modified.
The Z-spec says "if O already has a parent, it is first removed."
Now delegates to remove_object() before inserting.
The 0xBE prefix byte triggers extended opcode parsing. Reads the
opcode number from the next byte, then parses operand types using
the same format as VAR opcodes. Required for all V5+ games.
V8 uses the same format as V5 (object model, opcodes, stack) with
two differences: packed address scaling (×8 instead of ×4) and max
file size (512KB instead of 256KB).
zmemory: add V8 size validation and packed_address case
zobjectparser: accept version 8 alongside 4-5 in all checks
zstackmanager: allow V8 stack initialization
V6-7 remain unsupported (different packed address format with offsets).
quetzal.py: typo in _parse_umem() — cmem.dynamic_start should be
cmem._dynamic_start. Would crash on uncompressed memory restore.
zcpu.py: op_erase_window had if/if/else instead of if/elif/else.
When window_number was -1, the second if fell through to else,
calling erase_window(-1) after the correct reset path.
The Quetzal spec stores the PC pointing at the save instruction's
branch data. On restore, this branch must be processed as "save
succeeded" to advance the PC to the actual next instruction. Without
this, the branch bytes were decoded as an opcode, corrupting execution.
Detect the save opcode (0xB5) immediately before the restored PC to
distinguish in-game saves from out-of-band saves (which don't need
branch processing). Also improve error diagnostics: pop_stack now
raises ZStackPopError with frame context, and the instruction trace
dumps on all exceptions.
return_pc for each frame belongs on the caller's program_counter (the
resume address when this routine exits). varnum is the store variable
that receives the return value, stored as return_addr on the frame
itself. Also handle flags bit 4 (discard result → return_addr=None).
The Quetzal save format only stores the number of local vars the
routine declared, but the runtime indexes local_vars[0..14] for any
variable access. Restored routines had short lists, causing IndexError
on the first command after restore.
QuetzalParser._parse_stks() creates a new ZStackManager and sets it on
zmachine._stackmanager, but ZCpu._stackmanager and ZOpDecoder._stack
still pointed to the old empty stack. After restore, all stack ops
(local var reads, routine returns, stack pops) used the wrong stack,
causing the interpreter to crash on the first command.
Replaces the async _do_restore() (called after thread launch) with a
synchronous _try_restore() called before the thread starts. This
eliminates the race condition where restore mutates z-machine state
while the interpreter thread is running.
The restore prefix message is now part of start()'s return value
instead of being sent separately in play.py.
EmbeddedIFSession runs the hybrid interpreter in a daemon thread,
bridged to the async MUD loop via threading.Event synchronization.
.z3 files use the embedded path; other formats fall back to dfrotz.
- MUD ZUI components: MudScreen (buffered output), MudInputStream
(thread-safe input), MudFilesystem (quetzal saves), NullAudio
- save/restore via QuetzalWriter/QuetzalParser and :: escape commands
- state inspection: get_location_name(), get_room_objects()
- error reporting for interpreter crashes
- fix quetzal parser bit slice bug: _parse_stks used [0:3] (3 bits,
max 7 locals) instead of [0:4] (4 bits, max 15) — Zork uses 15
Implement V3 restore opcode:
- Add QuetzalParser.load_from_bytes() to parse save data from memory
- Wire op_restore to call filesystem.restore_game() and parse result
- Validate IFhd matches current story (release/serial/checksum)
- Restore dynamic memory, call stack, and program counter
- Branch true on success, false on failure/cancellation
Fix IFF chunk padding bug:
- Add padding byte to odd-length chunks in QuetzalWriter
- Ensures proper chunk alignment for parser compatibility
Add comprehensive tests:
- Branch false when filesystem returns None
- Branch false without zmachine reference
- Branch true on successful restore
- Verify memory state matches saved values
- Handle malformed save data gracefully
Implement full save functionality for V3 z-machine:
- Fixed QuetzalWriter._generate_anno_chunk() to return bytes
- Added QuetzalWriter.generate_save_data() to produce IFF container
- Updated QuetzalWriter.write() to use new method and binary mode
- Added zmachine reference to ZCpu for QuetzalWriter access
- Added _program_counter property to ZCpu for Quetzal access
- Implemented op_save to call QuetzalWriter and filesystem
- Updated tests for op_save (success, failure, IFF validation)
- Added filesystem mock to MockUI for testing
- Added _call_stack to MockStackManager for QuetzalWriter
All tests pass. Save now generates valid IFF/FORM/IFZS data with
IFhd, CMem, Stks, and ANNO chunks.
The IFhd chunk contains 13 bytes of metadata identifying the story
and current execution state:
- Release number (2 bytes) from header
- Serial number (6 bytes) from header
- Checksum (2 bytes) from header
- Program counter (3 bytes) from CPU state
This allows save files to be validated against the story file.
