1 ;;; ez.el --- Emacs Z-machine
3 ;; Copyright (C) 2021,2022,2023 Tim Vaughan
5 ;; Author: Tim Vaughan <plugd@thelambdalab.xyz>
6 ;; Created: 13 Oct 2021
9 ;; Homepage: http://thelambdalab.xyz/ez
10 ;; Package-Requires: ((emacs "26"))
12 ;; This file is not part of GNU Emacs.
14 ;; This program is free software: you can redistribute it and/or modify
15 ;; it under the terms of the GNU General Public License as published by
16 ;; the Free Software Foundation, either version 3 of the License, or
17 ;; (at your option) any later version.
19 ;; This program is distributed in the hope that it will be useful,
20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 ;; GNU General Public License for more details.
24 ;; You should have received a copy of the GNU General Public License
25 ;; along with this file. If not, see <http://www.gnu.org/licenses/>.
29 ;; There are many Z-machine interpreters, but this one is mine.
30 ;; It only capable of interpreting the subset of Z-code necessary
31 ;; to run the first Zork game in z3 format.
33 ;; It is based entirely on the description of the Z-machine contained
34 ;; Marnix Klooster's wonderful document, "The Z-machine And How to Emulate It."
40 (defun ez-decode-signed-bits (n nbits)
41 (if (= 0 (lsh n (- 1 nbits)))
45 (defun ez-decode-signed-byte (b)
46 (ez-decode-signed-bits b 8))
48 (defun ez-decode-signed-word (w)
49 (ez-decode-signed-bits w 16))
51 (defun ez-decode-signed-operand (operand operand-type)
52 (if (eq operand-type 'b)
53 (ez-decode-signed-byte operand)
54 (ez-decode-signed-word operand)))
56 (defun binformat (n &optional s)
60 (new-s (concat (number-to-string (mod n 2)) s)))
63 (binformat d new-s))))
65 (defun ez-list-to-string-hex (l)
70 (apply 'concat (mapcar (lambda (n) (format " %x" n)) (cdr l)))))
76 "Memory of z-machine.")
78 (defvar ez-version nil)
80 (defvar ez-start-pc nil)
81 (defvar ez-himem-base nil)
82 (defvar ez-dict-base nil)
83 (defvar ez-objtab-addr nil)
84 (defvar ez-abbrevtab-addr nil)
85 (defvar ez-globalvartab-addr nil)
87 (defvar ez-dict-entries nil
90 (defvar ez-dict-separators nil
93 (defun ez-mem-ref-byte (addr)
94 (aref ez-memory addr))
96 (defun ez-mem-set-byte (addr val)
97 (aset ez-memory addr val))
99 (defun ez-mem-set-bytes (addr vals)
100 (dotimes (i (length vals))
101 (ez-mem-set-byte (+ addr i) (elt vals i))))
103 (defun ez-mem-ref-word (addr)
104 (+ (* 256 (aref ez-memory addr))
105 (aref ez-memory (+ addr 1))))
107 (defun ez-mem-set-word (addr val)
108 (let ((byte-high (/ val 256))
109 (byte-low (mod val 256)))
110 (aset ez-memory addr byte-high)
111 (aset ez-memory (+ addr 1) byte-low)))
113 (defun ez-mem-ref-string (addr1 addr2)
114 (substring ez-memory addr1 addr2))
116 (defun ez-parse-header ()
117 (setq ez-version (ez-mem-ref-byte #x0))
118 (setq ez-himem-addr (ez-mem-ref-word #x4))
119 (setq ez-start-pc (ez-mem-ref-word #x6))
120 (setq ez-dict-base (ez-mem-ref-word #x8))
121 (setq ez-objtab-addr (ez-mem-ref-word #xA))
122 (setq ez-globalvartab-addr (ez-mem-ref-word #xC))
123 (setq ez-abbrevtab-addr (ez-mem-ref-word #x18)))
125 (defun ez-load-file (filename)
126 "Load story file into memory."
128 (insert-file-contents-literally filename)
129 (setq ez-memory (encode-coding-string (buffer-string) 'raw-text)))
134 (defun ez-get-global-var (gvar)
136 (error "Invalid global variable %d" gvar))
138 (ez-mem-ref-word (+ (* 2 gvar) ez-globalvartab-addr))))
139 (ez-debug-message "\tRetrieved %x from global variable %x" val gvar)
142 (defun ez-set-global-var (gvar val)
143 (ez-mem-set-word (+ (* 2 gvar) ez-globalvartab-addr) val)
144 (ez-debug-message "\tSet global variabl %x to %x" gvar val))
148 (defvar ez-property-defaults nil)
150 (defun ez-load-property-defaults ()
151 (setq ez-property-defaults (make-vector 31 0))
153 (aset ez-property-defaults i (aref ez-memory (+ ez-objtab-addr (* 2 i))))))
155 (defun ez-get-obj-addr (obj)
156 (+ ez-objtab-addr (* 2 31) (* 9 (- obj 1))))
158 (defun ez-get-obj-parent (obj)
159 (let ((addr (ez-get-obj-addr obj)))
160 (ez-mem-ref-byte (+ addr 4))))
162 (defun ez-set-obj-parent (obj new-parent)
163 (let ((addr (ez-get-obj-addr obj)))
164 (ez-mem-set-byte (+ addr 4) new-parent)))
166 (defun ez-get-obj-sibling (obj)
167 (let ((addr (ez-get-obj-addr obj)))
168 (ez-mem-ref-byte (+ addr 5))))
170 (defun ez-set-obj-sibling (obj new-sibling)
171 (let ((addr (ez-get-obj-addr obj)))
172 (ez-mem-set-byte (+ addr 5) new-sibling)))
174 (defun ez-get-obj-child (obj)
175 (let ((addr (ez-get-obj-addr obj)))
176 (ez-mem-ref-byte (+ addr 6))))
178 (defun ez-set-obj-child (obj new-child)
179 (let ((addr (ez-get-obj-addr obj)))
180 (ez-mem-set-byte (+ addr 6) new-child)))
182 (defun ez-get-obj-plist-addr (obj)
183 (let ((addr (ez-get-obj-addr obj)))
184 (ez-mem-ref-word (+ addr 7))))
186 (defun ez-get-obj-name (obj)
187 (let ((plist-addr (ez-get-obj-plist-addr obj)))
188 (if (> (ez-mem-ref-byte plist-addr) 0)
189 (ez-get-zstring (+ 1 (ez-get-obj-plist-addr obj)))
192 (defun ez-get-prop-default (prop)
193 (ez-mem-ref-word (+ ez-objtab-addr (* 2 (+ 1 prop)))))
195 (defun ez-get-prop-len (prop-size-byte)
196 (lsh prop-size-byte -5))
198 (defun ez-get-prop-num (prop-size-byte)
199 (logand #b00011111 prop-size-byte))
201 (defun ez-get-obj-prop-addr (obj prop)
202 (let* ((plist-addr (ez-get-obj-plist-addr obj))
203 (prop-addr (+ plist-addr 1 (* 2 (ez-mem-ref-byte plist-addr))))
204 (size-byte (ez-mem-ref-byte prop-addr)))
205 (while (not (or (= size-byte 0)
206 (= prop (ez-get-prop-num size-byte))))
207 (setq prop-addr (+ prop-addr (ez-get-prop-len size-byte) 2)
208 size-byte (ez-mem-ref-byte prop-addr)))
211 (defun ez-get-obj-prop (obj prop)
212 (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
213 (size-byte (ez-mem-ref-byte prop-addr)))
215 (ez-get-prop-default prop)
216 (let ((prop-len (ez-get-prop-len size-byte))
217 (data-addr (+ prop-addr 1)))
220 (ez-mem-ref-byte data-addr))
222 (ez-mem-ref-word data-addr)))))))
224 (defun ez-set-obj-prop (obj prop value)
225 (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
226 (size-byte (ez-mem-ref-byte prop-addr)))
229 (error "Tried to set non-existant property"))
230 ((= (ez-get-prop-len size-byte) 1)
231 (ez-mem-set-byte (+ prop-addr 1) value))
233 (ez-mem-set-word (+ prop-addr 1) value)))))
235 (defun ez-get-obj-attr (obj attr)
236 (let* ((byte-num (/ attr 8))
237 (bit-num (mod attr 8))
238 (bit-mask (lsh 1 (- 7 bit-num))))
239 (if (> (logand bit-mask (ez-mem-ref-byte (+ (ez-get-obj-addr obj) byte-num))) 0)
243 (defun ez-set-obj-attr (obj attr val)
244 (let* ((byte-num (/ attr 8))
245 (bit-num (mod attr 8))
246 (bit-mask (lsh 1 (- 7 bit-num)))
247 (byte-addr (+ (ez-get-obj-addr obj) byte-num))
248 (byte (ez-mem-ref-byte byte-addr))
249 (current-set (> (logand bit-mask byte) 0)))
250 (if (or (and current-set (= val 0))
251 (and (not current-set) (> val 0)))
252 (ez-mem-set-byte byte-addr (logxor byte bit-mask)))))
255 (defun ez-remove-obj (obj)
256 (let ((parent (ez-get-obj-parent obj))
257 (sibling (ez-get-obj-sibling obj)))
259 (let ((child (ez-get-obj-child parent)))
261 (ez-set-obj-child parent sibling)
262 (while (not (= obj (ez-get-obj-sibling child)))
263 (setq child (ez-get-obj-sibling child)))
264 (ez-set-obj-sibling child (ez-get-obj-sibling obj))))
265 (ez-set-obj-parent obj 0))
266 (ez-set-obj-sibling obj 0)))
268 (defun ez-insert-obj (obj new-parent)
270 (unless (= new-parent 0)
271 (ez-set-obj-sibling obj (ez-get-obj-child new-parent))
272 (ez-set-obj-child new-parent obj)))
276 (defvar ez-zstring-alphabets
279 (list " abcdefghijklmnopqrstuvwxyz"
280 " ABCDEFGHIJKLMNOPQRSTUVWXYZ"
281 " \n0123456789.,!?_#'\"/\\-:()")
282 "Alphabets used by V3")
284 (defun ez-parse-zstring-word (word)
286 (logand (lsh word -10) #b11111)
287 (logand (lsh word -5) #b11111)
288 (logand word #b11111)))
290 (defun ez-get-zstring-chars-and-length (base-addr)
291 (let ((addr base-addr)
296 (let ((components (ez-parse-zstring-word (ez-mem-ref-word addr))))
297 (setq chars (append chars (cdr components)))
298 (setq addr (+ addr 2))
299 (setq word-count (+ word-count 1))
300 (when (= (car components) 1)
301 (setq not-done nil))))
302 (cons word-count chars)))
304 (defun ez-get-zstring-and-length (base-addr)
305 (let* ((word-count-and-chars (ez-get-zstring-chars-and-length base-addr))
306 (word-count (car word-count-and-chars))
307 (chars (cdr word-count-and-chars))
311 (while (> (length chars) 0)
312 (let ((char (pop chars)))
314 ((memq char '(1 2 3)) ;Abbreviation
315 (let* ((abbrev-char char)
317 (* 2 (ez-mem-ref-word (+ ez-abbrevtab-addr
318 (* 2 (+ (* (- abbrev-char 1) 32) (pop chars))))))))
319 (setq s (concat s (cdr (ez-get-zstring-and-length abbrev-addr))))))
321 (setq cur (mod (+ cur 1) 3)))
323 (setq cur (mod (+ 3 (- cur 1)) 3)))
324 ((and (= cur 2) (= char 6))
325 (setq s (concat s (char-to-string (+ (lsh (pop chars) 5) (pop chars)))))
328 (setq s (concat s (substring (elt ez-zstring-alphabets cur)
331 (cons word-count s)))
333 (defun ez-get-zstring (base-addr)
334 (cdr (ez-get-zstring-and-length base-addr)))
336 (defun ez-encode (string)
337 "Encodes a string as a 2-word 5-padded Z-string.
338 Used for matching input with dictionary entries when tokenizing."
343 ((seq-contains-p (elt ez-zstring-alphabets 0) c)
344 (list (seq-position (elt ez-zstring-alphabets 0) c)))
345 ((seq-contains-p (elt ez-zstring-alphabets 1) c)
346 (list 4 (seq-position (elt ez-zstring-alphabets 1) c)))
347 ((seq-contains-p (elt ez-zstring-alphabets 2) c)
348 (list 5 (seq-position (elt ez-zstring-alphabets 2) c)))
350 (list 5 6 (lsh c -5) (logand c #b11111)))))
352 (if (< (length chars) 6)
353 (append chars (make-list (- 6 (length chars)) 5))
358 (defun ez-parse-dictionary-header ()
359 (let* ((nseps (ez-mem-ref-byte ez-dict-base))
361 (mapcar (lambda (i) (ez-mem-ref-byte (+ ez-dict-base i)))
362 (number-sequence 1 nseps)))
363 (bytes-per-entry (ez-mem-ref-byte (+ ez-dict-base 1 nseps)))
364 (nentries (ez-mem-ref-word (+ ez-dict-base 2 nseps)))
365 (entries-base (+ ez-dict-base nseps 4))
367 ;; (dotimes (i nentries)
368 ;; (let ((this-base (+ entries-base (* bytes-per-entry i))))
369 ;; (setq entries (cons (cons (ez-get-zstring this-base)
372 ;; (setq ez-dict-entries (reverse entries))
373 (setq ez-dict-separators separators)))
375 (defun ez-is-separator (char)
376 (let* ((nseps (ez-mem-ref-byte ez-dict-base)))
377 (while (and (> nseps 0)
378 (not (= (ez-mem-ref-byte (+ ez-dict-base nseps))
380 (setq nseps (- nseps 1)))
383 (defun ez-lookup-dictionary (text)
384 (let ((encoded-text (ez-encode text))
385 (nseps (ez-mem-ref-byte ez-dict-base))
386 (bytes-per-entry (ez-mem-ref-byte (+ ez-dict-base 1 nseps)))
387 (nentries (ez-mem-ref-word (+ ez-dict-base 2 nseps)))
389 (this-entry (+ ez-dict-base nseps 4)))
391 (while (and (< entries-seen nentries)
393 (ez-mem-ref-bytes this-entry 4)
395 (setq entries-seen (+ entries-seen 1))
396 (setq this-entry (+ this-entry bytes-per-entry)))
398 (if (< entries-seen nentries)
404 (defvar ez-call-stack nil)
406 (defun ez-make-call-stack-frame (pc &optional call-method)
412 (defun ez-add-call-stack-frame (pc &optional call-method)
413 (push (ez-make-call-stack-frame pc call-method) ez-call-stack))
415 (defun ez-pop-call-stack-frame ()
418 (defun ez-routine-stack ()
419 (elt (car ez-call-stack) 1))
421 (defun ez-routine-stack-push (val)
422 (let ((frame (car ez-call-stack)))
423 (ez-debug-message "\tPushed %x to stack" val)
424 (setf (elt frame 1) (cons val (elt frame 1)))))
426 (defun ez-routine-stack-pop ()
427 (let* ((frame (car ez-call-stack))
428 (rs-head (car (elt frame 1))))
429 (setf (elt frame 1) (cdr (elt frame 1)))
430 (ez-debug-message "\tPopped %x from stack" rs-head)
433 (defun ez-get-local-var (lvar)
434 (let* ((frame (car ez-call-stack))
435 (val (aref (elt frame 2) (- lvar 1))))
436 (ez-debug-message "\tRetrieved value %x from local variable %x" val lvar)
439 (defun ez-set-local-var (lvar val)
440 (let ((frame (car ez-call-stack)))
441 (ez-debug-message "\tSet local variable %x to %x" lvar val)
442 (aset (elt frame 2) (- lvar 1) val)))
445 (caar ez-call-stack))
447 (defun ez-set-pc (new-pc)
448 (setf (car (car ez-call-stack)) new-pc))
450 (defun ez-increment-pc (inc)
451 (ez-set-pc (+ (ez-get-pc) inc)))
453 (defun ez-read-pc-byte-and-inc ()
454 (let ((res (ez-mem-ref-byte (ez-get-pc))))
458 (defun ez-read-pc-word-and-inc ()
459 (let ((res (ez-mem-ref-word (ez-get-pc))))
463 ;; Instruction execution
465 (defun ez-get-var (var)
468 (ez-routine-stack-pop))
470 (ez-get-local-var var))
472 (ez-get-global-var (- var 16)))))
474 (defun ez-set-var (var val)
477 (ez-routine-stack-push val))
479 (ez-set-local-var var val))
481 (ez-set-global-var (- var 16) val))))
483 (defun ez-read-pc-var-and-inc ()
484 (ez-get-var (ez-read-pc-byte-and-inc)))
486 (defun ez-execute-instr ()
487 (let ((instr-pc (ez-get-pc))
488 (opbyte (ez-read-pc-byte-and-inc))
489 (optype) (opcode) (operands))
491 ((<= #x0 opbyte #x1f)
494 operands (list (ez-read-pc-byte-and-inc)
495 (ez-read-pc-byte-and-inc))
496 operand-types '(b b)))
497 ((<= #x20 opbyte #x3F)
499 opcode (- opbyte #x20)
500 operands (list (ez-read-pc-byte-and-inc)
501 (ez-read-pc-var-and-inc))
502 operand-types '(b w)))
503 ((<= #x40 opbyte #x5F)
505 opcode (- opbyte #x40)
506 operands (list (ez-read-pc-var-and-inc)
507 (ez-read-pc-byte-and-inc))
508 operand-types '(w b)))
509 ((<= #x60 opbyte #x7F)
511 opcode (- opbyte #x60)
512 operands (list (ez-read-pc-var-and-inc)
513 (ez-read-pc-var-and-inc))
514 operand-types '(w w)))
515 ((<= #x80 opbyte #x8F)
517 opcode (- opbyte #x80)
518 operands (list (ez-read-pc-word-and-inc))
520 ((<= #x90 opbyte #x9F)
522 opcode (- opbyte #x90)
523 operands (list (ez-read-pc-byte-and-inc))
525 ((<= #xA0 opbyte #xAF)
527 opcode (- opbyte #xa0)
528 operands (list (ez-read-pc-var-and-inc))
530 ((<= #xB0 opbyte #xBF)
532 opcode (- opbyte #xb0)
535 ((<= #xC0 opbyte #xDF)
537 opcode (- opbyte #xc0))
538 (let ((operands-and-types (ez-read-var-operands-and-inc)))
539 (setq operands (car operands-and-types)
540 operand-types (cdr operands-and-types))))
541 ((<= #xE0 opbyte #xFF)
543 opcode (- opbyte #xe0))
544 (let ((operands-and-types (ez-read-var-operands-and-inc)))
545 (setq operands (car operands-and-types)
546 operand-types (cdr operands-and-types)))))
547 (let ((table-row (assoc (list optype opcode) ez-op-table)))
549 (error "Unsupported op PC:%x Optype:%s Opcode:%x Operands:%s Operand-types:%s"
550 instr-pc optype opcode (ez-list-to-string-hex operands) operand-types))
551 (let ((mnemonic (elt table-row 1)))
552 (ez-debug-message "PC:%x Optype:%s Opcode:%x Mnemonic:%s Operands:%s Operand-types:%s"
553 instr-pc optype opcode mnemonic
554 (ez-list-to-string-hex operands) operand-types))
555 (funcall (elt table-row 2) operands operand-types))))
557 (defun ez-read-var-operands-and-inc ()
558 (let* ((type-byte (ez-read-pc-byte-and-inc))
559 (types (let ((type1 (lsh type-byte -6)))
563 (let ((type2 (mod (lsh type-byte -4) 4)))
567 (let ((type3 (mod (lsh type-byte -2) 4)))
571 (let ((type4 (mod type-byte 4)))
574 (list type4))))))))))))))
579 ((= type 0) (ez-read-pc-word-and-inc))
580 ((= type 1) (ez-read-pc-byte-and-inc))
581 ((= type 2) (ez-read-pc-var-and-inc))))
592 (defun ez-do-branch (branch)
593 (let* ((branch-byte (ez-read-pc-byte-and-inc))
594 (invert (= 0 (logand branch-byte #b10000000)))
595 (single-byte (> (logand branch-byte #b01000000) 0))
598 (logand branch-byte #b00111111)
599 (let ((pos (= (logand branch-byte #b00100000) 0))
600 (val (+ (* 256 (logand branch-byte #b00011111))
601 (ez-read-pc-byte-and-inc))))
605 (if (or (and branch (not invert))
606 (and (not branch) invert))
613 (ez-set-pc (+ (ez-get-pc) offset -2)))))))
618 '(((0op #x00) rtrue ez-op-rtrue)
619 ((0op #x01) rfalse ez-op-rfalse)
620 ((1op #x00) jz ez-op-jz)
621 ((1op #x05) inc ez-op-inc)
622 ((1op #x06) dec ez-op-dec)
623 ((1op #x0B) ret ez-op-ret)
624 ((0op #x08) ret_pulled ez-op-ret-pulled)
625 ((1op #x0C) jump ez-op-jump)
626 ((2op #x05) inc_jg ez-op-inc-jg)
627 ((2op #x04) dec_jg ez-op-dec-jg)
628 ((2op #x0D) store ez-op-store)
629 ((1op #x0E) load ez-op-load)
630 ((var #x01) storew ez-op-storew)
631 ((2op #x0F) loadw ez-op-loadw)
632 ((var #x02) storeb ez-op-storeb)
633 ((2op #x10) loadb ez-op-loadb)
634 ((2op #x01) je ez-op-je)
635 ((2op #x02) jl ez-op-jl)
636 ((2op #x03) jg ez-op-jg)
637 ((2op #x06) jin ez-op-jin)
638 ((2op #x07) test ez-op-test)
639 ((2op #x08) or ez-op-or)
640 ((2op #x09) and ez-op-and)
641 ((2op #x14) add ez-op-add)
642 ((2op #x15) sub ez-op-sub)
643 ((2op #x16) mul ez-op-mul)
644 ((2op #x17) div ez-op-div)
645 ((2op #x18) mod ez-op-mod)
646 ((var #x00) call_fv ez-op-callfv)
647 ((1op #x01) get_sibling ez-op-get-sibling)
648 ((1op #x02) get_child ez-op-get-child)
649 ((1op #x03) get_parent ez-op-get-parent)
650 ((2op #x0A) test_attr ez-op-test-attr)
651 ((2op #x0B) set_attr ez-op-set-attr)
652 ((2op #x0C) clear_attr ez-op-clear-attr)
653 ((1op #x09) remove_obj ez-op-remove-obj)
654 ((2op #x0E) insert_obj ez-op-insert-obj)
655 ((var #x03) put_prop ez-op-put-prop)
656 ((2op #x11) get_prop ez-op-get-prop)
657 ((0op #x02) print ez-op-print)
658 ((0op #x0B) new_line ez-op-new-line)
659 ((var #x06) print_num ez-op-print-num)
660 ((var #x05) print_char ez-op-print-char)
661 ((1op #x0A) print_obj ez-op-print-obj)
662 ((var #x04) read ez-op-read)))
664 (defun ez-op-ret (operands &optional operand-types)
665 (let ((retval (car operands)))
666 (ez-debug-message "\tReturning value %x" retval)
667 (ez-pop-call-stack-frame)
668 (ez-set-var (ez-read-pc-byte-and-inc) retval))
671 (defun ez-op-ret-pulled (operands operand-types)
672 (let ((retval (ez-routine-stack-pop)))
673 (ez-debug-message "\tReturning value %x" retval)
674 (ez-op-ret (list retval)))
677 (defun ez-op-rtrue (&optional operands operand-types)
681 (defun ez-op-rfalse (&optional operands operand-types)
685 (defun ez-op-jz (operands operand-types)
686 (ez-do-branch (= (car operands) 0))
689 (defun ez-op-je (operands operand-types)
690 (ez-do-branch (memq (car operands) (cdr operands)))
693 (defun ez-op-jg (operands operand-types)
694 (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
695 (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
696 (ez-do-branch (> s1 s2)))
699 (defun ez-op-jl (operands operand-types)
700 (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
701 (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
702 (ez-do-branch (< s1 s2)))
705 (defun ez-op-inc-jg (operands operand-types)
706 (let ((var (car operands)))
707 (ez-op-inc (list var))
708 (ez-op-jg (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
711 (defun ez-op-dec-jl (operands operand-types)
712 (let ((var (car operands)))
713 (ez-op-dec (list var))
714 (ez-op-jl (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
717 (defun ez-op-jin (operands operand-types)
718 (let ((obj (car operands))
720 (ez-do-branch (or (= n 0)
721 (= n (ez-get-obj-parent obj)))))
724 (defun ez-op-test (operands operand-types)
725 (let ((a (car operands))
727 (ez-do-branch (= (logand a b) b)))
730 (defun ez-op-jump (operands operand-types)
731 (let ((offset (if (eq (car operand-types) 'b)
732 (ez-decode-signed-byte (car operands))
733 (ez-decode-signed-word (car operands)))))
734 (ez-set-pc (+ (ez-get-pc) offset -2)))
737 (defun ez-op-inc (operands &optional operand-types)
738 (let ((var (car operands)))
739 (ez-set-var var (mod (+ 1 (ez-get-var var)) #x10000)))
742 (defun ez-op-dec (operands &optional operand-types)
743 (let ((var (car operands)))
744 (ez-set-var var (mod (+ (ez-get-var var) 1) #x10000)))
747 (defun ez-op-store (operands operand-types)
748 (let ((var (car operands))
753 (defun ez-op-load (operands operand-types)
754 (let ((var (car operands)))
755 (ez-set-var (ez-read-pc-byte-and-inc) (ez-get-var var)))
758 (defun ez-op-storew (operands operand-types)
759 (let ((baddr (car operands))
761 (a (caddr operands)))
762 (ez-mem-set-word (+ baddr (* 2 n)) a))
765 (defun ez-op-loadw (operands operand-types)
766 (let ((baddr (car operands))
768 (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-word (+ baddr (* 2 n)))))
771 (defun ez-op-storeb (operands operand-types)
772 (let ((baddr (car operands))
774 (a (caddr operands)))
775 (ez-mem-set-byte (+ baddr n) a))
778 (defun ez-op-loadb (operands operand-types)
779 (let ((baddr (car operands))
781 (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-byte (+ baddr n))))
784 (defun ez-op-and (operands operand-types)
785 (let ((a (car operands))
787 (ez-set-var (ez-read-pc-byte-and-inc) (logand a b)))
790 (defun ez-op-or (operands operand-types)
791 (let ((a (car operands))
793 (ez-set-var (ez-read-pc-byte-and-inc) (logior a b)))
796 (defun ez-op-add (operands operand-types)
797 (let ((a (car operands))
799 (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ a b) #x10000)))
802 (defun ez-op-sub (operands operand-types)
803 (let ((a (car operands))
805 (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ (- a b) #x10000) #x10000)))
808 (defun ez-op-mul (a b)
809 (let ((a (car operands))
811 (ez-set-var (ez-read-pc-byte-and-inc) (mod (* a b) #x10000)))
814 (defun ez-op-div (a b)
815 (error "Not implemented"))
817 (defun ez-op-mod (a b)
818 (error "Not implemented"))
820 (defun ez-op-callfv (operands operand-types)
821 (let* ((raddr (car operands))
822 (call-operands (cdr operands))
824 (L (ez-mem-ref-byte r))
825 (n (length call-operands))
826 (new-pc (+ r 1 (* L 2))))
828 (ez-set-var (ez-read-pc-byte-and-inc) 0) ; Simply return 0
829 (ez-add-call-stack-frame new-pc)
832 (ez-set-local-var (+ i 1) (elt call-operands i))
833 (ez-set-local-var (+ i 1) (ez-mem-ref-word (+ r 1 (* 2 i))))))))
836 (defun ez-op-test-attr (operands operand-types)
837 (let ((obj (car operands))
838 (attr (cadr operands)))
839 (ez-do-branch (= 1 (ez-get-obj-attr obj attr)))
842 (defun ez-op-set-attr (operands operand-types)
843 (let ((obj (car operands))
844 (attr (cadr operands)))
845 (ez-set-obj-attr obj attr 1))
848 (defun ez-op-clear-attr (operands operand-types)
849 (let ((obj (car operands))
850 (attr (cadr operands)))
851 (ez-set-obj-attr obj attr 0))
854 (defun ez-op-get-sibling (operands operand-types)
855 (let ((sib (ez-get-obj-sibling (car operands))))
856 (ez-set-var (ez-read-pc-byte-and-inc) sib)
857 (ez-do-branch (> sib 0)))
860 (defun ez-op-get-child (operands operand-types)
861 (let ((child (ez-get-obj-child (car operands))))
862 (ez-set-var (ez-read-pc-byte-and-inc) child)
863 (ez-do-branch (> child 0)))
866 (defun ez-op-get-parent (operands operand-types)
867 (let ((parent (ez-get-obj-parent (car operands))))
868 (ez-set-var (ez-read-pc-byte-and-inc) parent))
871 (defun ez-op-remove-obj (operands operand-types)
872 (let ((obj (car operands)))
876 (defun ez-op-insert-obj (operands operand-types)
877 (let ((obj1 (car operands))
878 (obj2 (cadr operands)))
879 (ez-insert-obj obj1 obj2))
882 (defun ez-op-put-prop (operands operand-types)
883 (let* ((obj (car operands))
884 (prop (cadr operands))
885 (a (caddr operands)))
886 (ez-set-obj-prop obj prop a))
889 (defun ez-op-get-prop (operands operand-types)
890 (let* ((obj (car operands))
891 (prop (cadr operands)))
892 (ez-set-var (ez-read-pc-byte-and-inc)
893 (ez-get-obj-prop obj prop)))
896 (defun ez-op-print (operands operand-types)
897 (let* ((word-count-and-string (ez-get-zstring-and-length (ez-get-pc)))
898 (word-count (car word-count-and-string))
899 (string (cdr word-count-and-string)))
901 (ez-increment-pc (* 2 word-count)))
904 (defun ez-op-new-line (operands operand-types)
908 (defun ez-op-print-num (operands operand-types)
909 (let ((s (ez-decode-signed-operand (car operands) (car operand-types))))
910 (ez-print (number-to-string s)))
913 (defun ez-op-print-char (operands operand-types)
914 (let ((c (car operands)))
915 (ez-print (string c)))
918 (defun ez-op-print-obj (operands operand-types)
919 (let ((obj (car operands)))
920 (ez-print (ez-get-obj-name obj)))
923 (defvar ez--next-read-args nil)
924 (defun ez-op-read (operands operand-types)
925 (let ((baddr1 (car operands))
926 (baddr2 (cadr operands)))
927 (setq ez--next-read-args (list baddr1 baddr2)))
930 (defun ez-op-read2 (input-string)
931 (let* ((baddr1 (car ez--next-read-args))
932 (baddr2 (cadr ez--next-read-args)))
934 (dotimes (i (length input-string))
935 (let ((char (elt input-string i)))
936 (ez-mem-set-byte (+ baddr1 1 i) char)))
937 (ez-mem-set-byte (+ baddr1 1 (length input-string)) 0)
939 (ez--tokenize baddr1 baddr2)))
941 (defun ez--tokenize (tb-baddr pb-baddr)
949 (let ((next-char (ez-mem-ref-byte (+ tb-baddr 1 token-end))))
953 (setq token-end (- token-end 1))
954 (let* ((text (ez-mem-ref-string (+ tb-baddr 1 token-start)
955 (+ tb-baddr 1 token-end)))
956 (dict-entry (ez-lookup-dictionary text)))
957 (setq token-count (+ token-count 1))
958 (ez-mem-set-word (+ pb-baddr 2 (* token-count 4))
960 (ez-mem-set-bytes (+ pb-baddr 2 (* token-count 4) 2)
963 (setq token-start (+ token-end 1))
964 (setq token-end token-start))
966 ((ez-is-separator char)
967 ;; Add token and separator token
970 (setq unfinished nil))
971 (setq token-end (+ token-end 1)))
976 (defun ez-load-and-run (filename)
977 (ez-load-file filename)
979 (ez-parse-dictionary)
980 (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
984 (defvar ez-machine-state nil
985 "Identifies the current executation state of the Z-machine.")
988 (setq ez-machine-state 'run)
989 (while (eq ez-machine-state 'run)
990 (setq ez-machine-state (ez-execute-instr))))
995 (defvar ez-input-marker nil
996 "Marker for input position in buffer.")
998 (defun ez-setup-buffer ()
999 (with-current-buffer (get-buffer-create "*ez*")
1001 (let ((inhibit-read-only t))
1003 (setq-local scroll-conservatively 1)
1004 (if (markerp ez-input-marker)
1005 (set-marker ez-input-marker (point-max))
1006 (setq ez-input-marker (point-max-marker)))
1007 (goto-char (point-max))))
1010 (defun ez-print (string)
1011 (with-current-buffer "*ez*"
1013 (goto-char ez-input-marker)
1014 (insert-before-markers string))))
1018 (if (not (eq ez-machine-state 'wait-for-input))
1019 (error "Z-machine not ready for input."))
1022 (with-current-buffer "*ez*"
1023 (buffer-substring ez-input-marker (point-max))))))
1024 (delete-region ez-input-marker (point-max))
1025 (ez-print (concat input-string "\n"))
1026 (ez-debug-message "\tReceived string \"%s\"" input-string)
1027 (ez-op-read2 input-string)
1032 (defun ez-setup-debug-buffer ()
1033 (with-current-buffer (get-buffer-create "*ez-debug-trace*")
1034 (setq-local buffer-read-only t)
1035 (let ((inhibit-read-only t))
1037 (insert "--- Trace Start ---\n\n"))))
1039 (defun ez-debug-message (&rest strings)
1040 (with-current-buffer (get-buffer-create "*ez-debug-trace*")
1042 (goto-char (point-max))
1043 (let ((inhibit-read-only t))
1044 (insert (apply #'format-message strings) "\n")))))
1046 (defun ez-debug-memory ()
1048 (with-current-buffer (get-buffer-create "*ez-debug-memory*")
1049 (setq-local buffer-read-only t)
1050 (let ((inhibit-read-only t)
1051 (old-point (point)))
1052 (if (eq major-mode 'hexl-mode)
1056 (setq-local buffer-undo-list nil)
1058 (goto-char old-point))))
1063 (let ((map (make-sparse-keymap)))
1064 (define-key map (kbd "RET") 'ez-enter)
1067 (define-derived-mode ez-mode text-mode "ez"
1068 "Major mode for EZ.")
1070 (when (fboundp 'evil-set-initial-state)
1071 (evil-set-initial-state 'ez-mode 'insert))
1074 (interactive "fEnter name of z3 story file: ")
1075 (if (get-buffer "*ez*")
1076 (switch-to-buffer "*ez*")
1077 (switch-to-buffer "*ez*")
1079 (ez-load-and-run zfile))
1085 (ez-setup-debug-buffer)
1086 (ez-load-and-run "zork1.z3"))