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-ref-bytes (addr count)
97 (mapcar (lambda (offset) (ez-mem-ref-byte (+ addr offset)))
98 (number-sequence 0 (- count 1))))
100 (defun ez-mem-set-byte (addr val)
101 (aset ez-memory addr val))
103 (defun ez-mem-set-bytes (addr vals)
104 (dotimes (i (length vals))
105 (ez-mem-set-byte (+ addr i) (elt vals i))))
107 (defun ez-mem-ref-word (addr)
108 (logior (lsh (aref ez-memory addr) 8)
109 (aref ez-memory (+ addr 1))))
111 (defun ez-mem-ref-words (addr count)
112 (mapcar (lambda (offset) (ez-mem-ref-word (+ addr offset)))
113 (number-sequence 0 (- (* 2 count) 1) 2)))
115 (defun ez-mem-set-word (addr val)
116 (let ((byte-high (/ val 256))
117 (byte-low (mod val 256)))
118 (aset ez-memory addr byte-high)
119 (aset ez-memory (+ addr 1) byte-low)))
121 (defun ez-mem-ref-string (addr1 addr2)
122 (substring ez-memory addr1 addr2))
124 (defun ez-parse-header ()
125 (setq ez-version (ez-mem-ref-byte #x0))
126 (setq ez-himem-addr (ez-mem-ref-word #x4))
127 (setq ez-start-pc (ez-mem-ref-word #x6))
128 (setq ez-dict-base (ez-mem-ref-word #x8))
129 (setq ez-objtab-addr (ez-mem-ref-word #xA))
130 (setq ez-globalvartab-addr (ez-mem-ref-word #xC))
131 (setq ez-abbrevtab-addr (ez-mem-ref-word #x18)))
133 (defun ez-load-file (filename)
134 "Load story file into memory."
136 (insert-file-contents-literally filename)
137 (setq ez-memory (encode-coding-string (buffer-string) 'raw-text)))
142 (defun ez-get-global-var (gvar)
144 (error "Invalid global variable %d" gvar))
146 (ez-mem-ref-word (+ (* 2 gvar) ez-globalvartab-addr))))
147 (ez-debug-message "\tRetrieved %x from global variable %x" val gvar)
150 (defun ez-set-global-var (gvar val)
151 (ez-mem-set-word (+ (* 2 gvar) ez-globalvartab-addr) val)
152 (ez-debug-message "\tSet global variabl %x to %x" gvar val))
156 (defvar ez-property-defaults nil)
158 (defun ez-load-property-defaults ()
159 (setq ez-property-defaults (make-vector 31 0))
161 (aset ez-property-defaults i (aref ez-memory (+ ez-objtab-addr (* 2 i))))))
163 (defun ez-get-obj-addr (obj)
164 (+ ez-objtab-addr (* 2 31) (* 9 (- obj 1))))
166 (defun ez-get-obj-parent (obj)
167 (let ((addr (ez-get-obj-addr obj)))
168 (ez-mem-ref-byte (+ addr 4))))
170 (defun ez-set-obj-parent (obj new-parent)
171 (let ((addr (ez-get-obj-addr obj)))
172 (ez-mem-set-byte (+ addr 4) new-parent)))
174 (defun ez-get-obj-sibling (obj)
175 (let ((addr (ez-get-obj-addr obj)))
176 (ez-mem-ref-byte (+ addr 5))))
178 (defun ez-set-obj-sibling (obj new-sibling)
179 (let ((addr (ez-get-obj-addr obj)))
180 (ez-mem-set-byte (+ addr 5) new-sibling)))
182 (defun ez-get-obj-child (obj)
183 (let ((addr (ez-get-obj-addr obj)))
184 (ez-mem-ref-byte (+ addr 6))))
186 (defun ez-set-obj-child (obj new-child)
187 (let ((addr (ez-get-obj-addr obj)))
188 (ez-mem-set-byte (+ addr 6) new-child)))
190 (defun ez-get-obj-plist-addr (obj)
191 (let ((addr (ez-get-obj-addr obj)))
192 (ez-mem-ref-word (+ addr 7))))
194 (defun ez-get-obj-name (obj)
195 (let ((plist-addr (ez-get-obj-plist-addr obj)))
196 (if (> (ez-mem-ref-byte plist-addr) 0)
197 (ez-get-zstring (+ 1 (ez-get-obj-plist-addr obj)))
200 (defun ez-get-prop-default (prop)
201 (ez-mem-ref-word (+ ez-objtab-addr (* 2 (+ 1 prop)))))
203 (defun ez-get-prop-len (prop-size-byte)
204 (lsh prop-size-byte -5))
206 (defun ez-get-prop-num (prop-size-byte)
207 (logand #b00011111 prop-size-byte))
209 (defun ez-get-obj-prop-addr (obj prop)
210 (let* ((plist-addr (ez-get-obj-plist-addr obj))
211 (prop-addr (+ plist-addr 1 (* 2 (ez-mem-ref-byte plist-addr))))
212 (size-byte (ez-mem-ref-byte prop-addr)))
213 (while (not (or (= size-byte 0)
214 (= prop (ez-get-prop-num size-byte))))
215 (setq prop-addr (+ prop-addr (ez-get-prop-len size-byte) 2)
216 size-byte (ez-mem-ref-byte prop-addr)))
219 (defun ez-get-obj-prop (obj prop)
220 (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
221 (size-byte (ez-mem-ref-byte prop-addr)))
223 (ez-get-prop-default prop)
224 (let ((prop-len (ez-get-prop-len size-byte))
225 (data-addr (+ prop-addr 1)))
228 (ez-mem-ref-byte data-addr))
230 (ez-mem-ref-word data-addr)))))))
232 (defun ez-set-obj-prop (obj prop value)
233 (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
234 (size-byte (ez-mem-ref-byte prop-addr)))
237 (error "Tried to set non-existant property"))
238 ((= (ez-get-prop-len size-byte) 1)
239 (ez-mem-set-byte (+ prop-addr 1) value))
241 (ez-mem-set-word (+ prop-addr 1) value)))))
243 (defun ez-get-obj-attr (obj attr)
244 (let* ((byte-num (/ attr 8))
245 (bit-num (mod attr 8))
246 (bit-mask (lsh 1 (- 7 bit-num))))
247 (if (> (logand bit-mask (ez-mem-ref-byte (+ (ez-get-obj-addr obj) byte-num))) 0)
251 (defun ez-set-obj-attr (obj attr val)
252 (let* ((byte-num (/ attr 8))
253 (bit-num (mod attr 8))
254 (bit-mask (lsh 1 (- 7 bit-num)))
255 (byte-addr (+ (ez-get-obj-addr obj) byte-num))
256 (byte (ez-mem-ref-byte byte-addr))
257 (current-set (> (logand bit-mask byte) 0)))
258 (if (or (and current-set (= val 0))
259 (and (not current-set) (> val 0)))
260 (ez-mem-set-byte byte-addr (logxor byte bit-mask)))))
263 (defun ez-remove-obj (obj)
264 (let ((parent (ez-get-obj-parent obj))
265 (sibling (ez-get-obj-sibling obj)))
267 (let ((child (ez-get-obj-child parent)))
269 (ez-set-obj-child parent sibling)
270 (while (not (= obj (ez-get-obj-sibling child)))
271 (setq child (ez-get-obj-sibling child)))
272 (ez-set-obj-sibling child (ez-get-obj-sibling obj))))
273 (ez-set-obj-parent obj 0))
274 (ez-set-obj-sibling obj 0)))
276 (defun ez-insert-obj (obj new-parent)
278 (unless (= new-parent 0)
279 (ez-set-obj-sibling obj (ez-get-obj-child new-parent))
280 (ez-set-obj-child new-parent obj)))
284 (defvar ez-zstring-alphabets
287 (list " abcdefghijklmnopqrstuvwxyz"
288 " ABCDEFGHIJKLMNOPQRSTUVWXYZ"
289 " \n0123456789.,!?_#'\"/\\-:()")
290 "Alphabets used by V3")
292 (defun ez-parse-zstring-word (word)
294 (logand (lsh word -10) #b11111)
295 (logand (lsh word -5) #b11111)
296 (logand word #b11111)))
298 (defun ez-make-zstring-word (zchar-triple)
299 (let ((c1 (elt zchar-triple 0))
300 (c2 (elt zchar-triple 1))
301 (c3 (elz zchar-triple 2)))
304 (defun ez-get-zstring-chars-and-length (base-addr)
305 (let ((addr base-addr)
310 (let ((components (ez-parse-zstring-word (ez-mem-ref-word addr))))
311 (setq chars (append chars (cdr components)))
312 (setq addr (+ addr 2))
313 (setq word-count (+ word-count 1))
314 (when (= (car components) 1)
315 (setq not-done nil))))
316 (cons word-count chars)))
318 (defun ez-get-zstring-and-length (base-addr)
319 (let* ((word-count-and-chars (ez-get-zstring-chars-and-length base-addr))
320 (word-count (car word-count-and-chars))
321 (chars (cdr word-count-and-chars))
325 (while (> (length chars) 0)
326 (let ((char (pop chars)))
328 ((memq char '(1 2 3)) ;Abbreviation
329 (let* ((abbrev-char char)
331 (* 2 (ez-mem-ref-word (+ ez-abbrevtab-addr
332 (* 2 (+ (* (- abbrev-char 1) 32) (pop chars))))))))
333 (setq s (concat s (cdr (ez-get-zstring-and-length abbrev-addr))))))
335 (setq cur (mod (+ cur 1) 3)))
337 (setq cur (mod (+ 3 (- cur 1)) 3)))
338 ((and (= cur 2) (= char 6))
339 (setq s (concat s (char-to-string (+ (lsh (pop chars) 5) (pop chars)))))
342 (setq s (concat s (substring (elt ez-zstring-alphabets cur)
345 (cons word-count s)))
347 (defun ez-get-zstring (base-addr)
348 (cdr (ez-get-zstring-and-length base-addr)))
350 (defun ez-encode (string)
351 "Encodes a string as a 2-word 5-padded Z-string.
352 Used for matching input with dictionary entries when tokenizing.
353 Returns a length-2 list of words for comparison with a dictionary entry."
358 ((seq-contains-p (elt ez-zstring-alphabets 0) c)
359 (list (seq-position (elt ez-zstring-alphabets 0) c)))
360 ((seq-contains-p (elt ez-zstring-alphabets 1) c)
361 (list 4 (seq-position (elt ez-zstring-alphabets 1) c)))
362 ((seq-contains-p (elt ez-zstring-alphabets 2) c)
363 (list 5 (seq-position (elt ez-zstring-alphabets 2) c)))
365 (list 5 6 (lsh c -5) (logand c #b11111)))))
367 (let* ((zstring-chars
368 (if (< (length chars) 6)
369 (append chars (make-list (- 6 (length chars)) 5))
371 (c1 (elt zstring-chars 0))
372 (c2 (elt zstring-chars 1))
373 (c3 (elt zstring-chars 2))
374 (c4 (elt zstring-chars 3))
375 (c5 (elt zstring-chars 4))
376 (c6 (elt zstring-chars 5)))
388 (defun ez-parse-dictionary-header ()
389 (let* ((nseps (ez-mem-ref-byte ez-dict-base))
391 (mapcar (lambda (i) (ez-mem-ref-byte (+ ez-dict-base i)))
392 (number-sequence 1 nseps)))
393 (bytes-per-entry (ez-mem-ref-byte (+ ez-dict-base 1 nseps)))
394 (nentries (ez-mem-ref-word (+ ez-dict-base 2 nseps)))
395 (entries-base (+ ez-dict-base nseps 4))
397 ;; (dotimes (i nentries)
398 ;; (let ((this-base (+ entries-base (* bytes-per-entry i))))
399 ;; (setq entries (cons (cons (ez-get-zstring this-base)
402 ;; (setq ez-dict-entries (reverse entries))
403 (setq ez-dict-separators separators)))
405 (defun ez-is-separator (char)
406 (let* ((nseps (ez-mem-ref-byte ez-dict-base)))
407 (while (and (> nseps 0)
408 (not (= (ez-mem-ref-byte (+ ez-dict-base nseps))
410 (setq nseps (- nseps 1)))
413 (defun ez-lookup-dictionary (text)
414 (let* ((encoded-text (ez-encode text))
415 (nseps (ez-mem-ref-byte ez-dict-base))
416 (bytes-per-entry (ez-mem-ref-byte (+ ez-dict-base 1 nseps)))
417 (nentries (ez-mem-ref-word (+ ez-dict-base 2 nseps)))
419 (this-entry (+ ez-dict-base nseps 4)))
421 (while (and (< entries-seen nentries)
423 (ez-mem-ref-words this-entry 2)
425 (setq entries-seen (+ entries-seen 1))
426 (setq this-entry (+ this-entry bytes-per-entry)))
428 (if (< entries-seen nentries)
434 (defvar ez-call-stack nil)
436 (defun ez-make-call-stack-frame (pc &optional call-method)
442 (defun ez-add-call-stack-frame (pc &optional call-method)
443 (push (ez-make-call-stack-frame pc call-method) ez-call-stack))
445 (defun ez-pop-call-stack-frame ()
448 (defun ez-routine-stack ()
449 (elt (car ez-call-stack) 1))
451 (defun ez-routine-stack-push (val)
452 (let ((frame (car ez-call-stack)))
453 (ez-debug-message "\tPushed %x to stack" val)
454 (setf (elt frame 1) (cons val (elt frame 1)))))
456 (defun ez-routine-stack-pop ()
457 (let* ((frame (car ez-call-stack))
458 (rs-head (car (elt frame 1))))
459 (setf (elt frame 1) (cdr (elt frame 1)))
460 (ez-debug-message "\tPopped %x from stack" rs-head)
463 (defun ez-get-local-var (lvar)
464 (let* ((frame (car ez-call-stack))
465 (val (aref (elt frame 2) (- lvar 1))))
466 (ez-debug-message "\tRetrieved value %x from local variable %x" val lvar)
469 (defun ez-set-local-var (lvar val)
470 (let ((frame (car ez-call-stack)))
471 (ez-debug-message "\tSet local variable %x to %x" lvar val)
472 (aset (elt frame 2) (- lvar 1) val)))
475 (caar ez-call-stack))
477 (defun ez-set-pc (new-pc)
478 (setf (car (car ez-call-stack)) new-pc))
480 (defun ez-increment-pc (inc)
481 (ez-set-pc (+ (ez-get-pc) inc)))
483 (defun ez-read-pc-byte-and-inc ()
484 (let ((res (ez-mem-ref-byte (ez-get-pc))))
488 (defun ez-read-pc-word-and-inc ()
489 (let ((res (ez-mem-ref-word (ez-get-pc))))
493 ;; Instruction execution
495 (defun ez-get-var (var)
498 (ez-routine-stack-pop))
500 (ez-get-local-var var))
502 (ez-get-global-var (- var 16)))))
504 (defun ez-set-var (var val)
507 (ez-routine-stack-push val))
509 (ez-set-local-var var val))
511 (ez-set-global-var (- var 16) val))))
513 (defun ez-read-pc-var-and-inc ()
514 (ez-get-var (ez-read-pc-byte-and-inc)))
516 (defun ez-execute-instr ()
517 (let ((instr-pc (ez-get-pc))
518 (opbyte (ez-read-pc-byte-and-inc))
519 (optype) (opcode) (operands))
521 ((<= #x0 opbyte #x1f)
524 operands (list (ez-read-pc-byte-and-inc)
525 (ez-read-pc-byte-and-inc))
526 operand-types '(b b)))
527 ((<= #x20 opbyte #x3F)
529 opcode (- opbyte #x20)
530 operands (list (ez-read-pc-byte-and-inc)
531 (ez-read-pc-var-and-inc))
532 operand-types '(b w)))
533 ((<= #x40 opbyte #x5F)
535 opcode (- opbyte #x40)
536 operands (list (ez-read-pc-var-and-inc)
537 (ez-read-pc-byte-and-inc))
538 operand-types '(w b)))
539 ((<= #x60 opbyte #x7F)
541 opcode (- opbyte #x60)
542 operands (list (ez-read-pc-var-and-inc)
543 (ez-read-pc-var-and-inc))
544 operand-types '(w w)))
545 ((<= #x80 opbyte #x8F)
547 opcode (- opbyte #x80)
548 operands (list (ez-read-pc-word-and-inc))
550 ((<= #x90 opbyte #x9F)
552 opcode (- opbyte #x90)
553 operands (list (ez-read-pc-byte-and-inc))
555 ((<= #xA0 opbyte #xAF)
557 opcode (- opbyte #xa0)
558 operands (list (ez-read-pc-var-and-inc))
560 ((<= #xB0 opbyte #xBF)
562 opcode (- opbyte #xb0)
565 ((<= #xC0 opbyte #xDF)
567 opcode (- opbyte #xc0))
568 (let ((operands-and-types (ez-read-var-operands-and-inc)))
569 (setq operands (car operands-and-types)
570 operand-types (cdr operands-and-types))))
571 ((<= #xE0 opbyte #xFF)
573 opcode (- opbyte #xe0))
574 (let ((operands-and-types (ez-read-var-operands-and-inc)))
575 (setq operands (car operands-and-types)
576 operand-types (cdr operands-and-types)))))
577 (let ((table-row (assoc (list optype opcode) ez-op-table)))
579 (error "Unsupported op PC:%x Optype:%s Opcode:%x Operands:%s Operand-types:%s"
580 instr-pc optype opcode (ez-list-to-string-hex operands) operand-types))
581 (let ((mnemonic (elt table-row 1)))
582 (ez-debug-message "PC:%x Optype:%s Opcode:%x Mnemonic:%s Operands:%s Operand-types:%s"
583 instr-pc optype opcode mnemonic
584 (ez-list-to-string-hex operands) operand-types))
585 (funcall (elt table-row 2) operands operand-types))))
587 (defun ez-read-var-operands-and-inc ()
588 (let* ((type-byte (ez-read-pc-byte-and-inc))
589 (types (let ((type1 (lsh type-byte -6)))
593 (let ((type2 (mod (lsh type-byte -4) 4)))
597 (let ((type3 (mod (lsh type-byte -2) 4)))
601 (let ((type4 (mod type-byte 4)))
604 (list type4))))))))))))))
609 ((= type 0) (ez-read-pc-word-and-inc))
610 ((= type 1) (ez-read-pc-byte-and-inc))
611 ((= type 2) (ez-read-pc-var-and-inc))))
622 (defun ez-do-branch (branch)
623 (let* ((branch-byte (ez-read-pc-byte-and-inc))
624 (invert (= 0 (logand branch-byte #b10000000)))
625 (single-byte (> (logand branch-byte #b01000000) 0))
628 (logand branch-byte #b00111111)
629 (let ((pos (= (logand branch-byte #b00100000) 0))
630 (val (+ (* 256 (logand branch-byte #b00011111))
631 (ez-read-pc-byte-and-inc))))
635 (if (or (and branch (not invert))
636 (and (not branch) invert))
643 (ez-set-pc (+ (ez-get-pc) offset -2)))))))
648 '(((0op #x00) rtrue ez-op-rtrue)
649 ((0op #x01) rfalse ez-op-rfalse)
650 ((1op #x00) jz ez-op-jz)
651 ((1op #x05) inc ez-op-inc)
652 ((1op #x06) dec ez-op-dec)
653 ((1op #x0B) ret ez-op-ret)
654 ((0op #x08) ret_pulled ez-op-ret-pulled)
655 ((1op #x0C) jump ez-op-jump)
656 ((2op #x05) inc_jg ez-op-inc-jg)
657 ((2op #x04) dec_jg ez-op-dec-jg)
658 ((2op #x0D) store ez-op-store)
659 ((1op #x0E) load ez-op-load)
660 ((var #x01) storew ez-op-storew)
661 ((2op #x0F) loadw ez-op-loadw)
662 ((var #x02) storeb ez-op-storeb)
663 ((2op #x10) loadb ez-op-loadb)
664 ((2op #x01) je ez-op-je)
665 ((2op #x02) jl ez-op-jl)
666 ((2op #x03) jg ez-op-jg)
667 ((2op #x06) jin ez-op-jin)
668 ((2op #x07) test ez-op-test)
669 ((2op #x08) or ez-op-or)
670 ((2op #x09) and ez-op-and)
671 ((2op #x14) add ez-op-add)
672 ((2op #x15) sub ez-op-sub)
673 ((2op #x16) mul ez-op-mul)
674 ((2op #x17) div ez-op-div)
675 ((2op #x18) mod ez-op-mod)
676 ((var #x00) call_fv ez-op-callfv)
677 ((1op #x01) get_sibling ez-op-get-sibling)
678 ((1op #x02) get_child ez-op-get-child)
679 ((1op #x03) get_parent ez-op-get-parent)
680 ((2op #x0A) test_attr ez-op-test-attr)
681 ((2op #x0B) set_attr ez-op-set-attr)
682 ((2op #x0C) clear_attr ez-op-clear-attr)
683 ((1op #x09) remove_obj ez-op-remove-obj)
684 ((2op #x0E) insert_obj ez-op-insert-obj)
685 ((var #x03) put_prop ez-op-put-prop)
686 ((2op #x11) get_prop ez-op-get-prop)
687 ((0op #x02) print ez-op-print)
688 ((0op #x0B) new_line ez-op-new-line)
689 ((var #x06) print_num ez-op-print-num)
690 ((var #x05) print_char ez-op-print-char)
691 ((1op #x0A) print_obj ez-op-print-obj)
692 ((var #x04) read ez-op-read)))
694 (defun ez-op-ret (operands &optional operand-types)
695 (let ((retval (car operands)))
696 (ez-debug-message "\tReturning value %x" retval)
697 (ez-pop-call-stack-frame)
698 (ez-set-var (ez-read-pc-byte-and-inc) retval))
701 (defun ez-op-ret-pulled (operands operand-types)
702 (let ((retval (ez-routine-stack-pop)))
703 (ez-debug-message "\tReturning value %x" retval)
704 (ez-op-ret (list retval)))
707 (defun ez-op-rtrue (&optional operands operand-types)
711 (defun ez-op-rfalse (&optional operands operand-types)
715 (defun ez-op-jz (operands operand-types)
716 (ez-do-branch (= (car operands) 0))
719 (defun ez-op-je (operands operand-types)
720 (ez-do-branch (memq (car operands) (cdr operands)))
723 (defun ez-op-jg (operands operand-types)
724 (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
725 (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
726 (ez-do-branch (> s1 s2)))
729 (defun ez-op-jl (operands operand-types)
730 (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
731 (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
732 (ez-do-branch (< s1 s2)))
735 (defun ez-op-inc-jg (operands operand-types)
736 (let ((var (car operands)))
737 (ez-op-inc (list var))
738 (ez-op-jg (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
741 (defun ez-op-dec-jl (operands operand-types)
742 (let ((var (car operands)))
743 (ez-op-dec (list var))
744 (ez-op-jl (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
747 (defun ez-op-jin (operands operand-types)
748 (let ((obj (car operands))
750 (ez-do-branch (or (= n 0)
751 (= n (ez-get-obj-parent obj)))))
754 (defun ez-op-test (operands operand-types)
755 (let ((a (car operands))
757 (ez-do-branch (= (logand a b) b)))
760 (defun ez-op-jump (operands operand-types)
761 (let ((offset (if (eq (car operand-types) 'b)
762 (ez-decode-signed-byte (car operands))
763 (ez-decode-signed-word (car operands)))))
764 (ez-set-pc (+ (ez-get-pc) offset -2)))
767 (defun ez-op-inc (operands &optional operand-types)
768 (let ((var (car operands)))
769 (ez-set-var var (mod (+ 1 (ez-get-var var)) #x10000)))
772 (defun ez-op-dec (operands &optional operand-types)
773 (let ((var (car operands)))
774 (ez-set-var var (mod (+ (ez-get-var var) 1) #x10000)))
777 (defun ez-op-store (operands operand-types)
778 (let ((var (car operands))
783 (defun ez-op-load (operands operand-types)
784 (let ((var (car operands)))
785 (ez-set-var (ez-read-pc-byte-and-inc) (ez-get-var var)))
788 (defun ez-op-storew (operands operand-types)
789 (let ((baddr (car operands))
791 (a (caddr operands)))
792 (ez-mem-set-word (+ baddr (* 2 n)) a))
795 (defun ez-op-loadw (operands operand-types)
796 (let ((baddr (car operands))
798 (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-word (+ baddr (* 2 n)))))
801 (defun ez-op-storeb (operands operand-types)
802 (let ((baddr (car operands))
804 (a (caddr operands)))
805 (ez-mem-set-byte (+ baddr n) a))
808 (defun ez-op-loadb (operands operand-types)
809 (let ((baddr (car operands))
811 (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-byte (+ baddr n))))
814 (defun ez-op-and (operands operand-types)
815 (let ((a (car operands))
817 (ez-set-var (ez-read-pc-byte-and-inc) (logand a b)))
820 (defun ez-op-or (operands operand-types)
821 (let ((a (car operands))
823 (ez-set-var (ez-read-pc-byte-and-inc) (logior a b)))
826 (defun ez-op-add (operands operand-types)
827 (let ((a (car operands))
829 (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ a b) #x10000)))
832 (defun ez-op-sub (operands operand-types)
833 (let ((a (car operands))
835 (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ (- a b) #x10000) #x10000)))
838 (defun ez-op-mul (a b)
839 (let ((a (car operands))
841 (ez-set-var (ez-read-pc-byte-and-inc) (mod (* a b) #x10000)))
844 (defun ez-op-div (a b)
845 (error "Not implemented"))
847 (defun ez-op-mod (a b)
848 (error "Not implemented"))
850 (defun ez-op-callfv (operands operand-types)
851 (let* ((raddr (car operands))
852 (call-operands (cdr operands))
854 (L (ez-mem-ref-byte r))
855 (n (length call-operands))
856 (new-pc (+ r 1 (* L 2))))
858 (ez-set-var (ez-read-pc-byte-and-inc) 0) ; Simply return 0
859 (ez-add-call-stack-frame new-pc)
862 (ez-set-local-var (+ i 1) (elt call-operands i))
863 (ez-set-local-var (+ i 1) (ez-mem-ref-word (+ r 1 (* 2 i))))))))
866 (defun ez-op-test-attr (operands operand-types)
867 (let ((obj (car operands))
868 (attr (cadr operands)))
869 (ez-do-branch (= 1 (ez-get-obj-attr obj attr)))
872 (defun ez-op-set-attr (operands operand-types)
873 (let ((obj (car operands))
874 (attr (cadr operands)))
875 (ez-set-obj-attr obj attr 1))
878 (defun ez-op-clear-attr (operands operand-types)
879 (let ((obj (car operands))
880 (attr (cadr operands)))
881 (ez-set-obj-attr obj attr 0))
884 (defun ez-op-get-sibling (operands operand-types)
885 (let ((sib (ez-get-obj-sibling (car operands))))
886 (ez-set-var (ez-read-pc-byte-and-inc) sib)
887 (ez-do-branch (> sib 0)))
890 (defun ez-op-get-child (operands operand-types)
891 (let ((child (ez-get-obj-child (car operands))))
892 (ez-set-var (ez-read-pc-byte-and-inc) child)
893 (ez-do-branch (> child 0)))
896 (defun ez-op-get-parent (operands operand-types)
897 (let ((parent (ez-get-obj-parent (car operands))))
898 (ez-set-var (ez-read-pc-byte-and-inc) parent))
901 (defun ez-op-remove-obj (operands operand-types)
902 (let ((obj (car operands)))
906 (defun ez-op-insert-obj (operands operand-types)
907 (let ((obj1 (car operands))
908 (obj2 (cadr operands)))
909 (ez-insert-obj obj1 obj2))
912 (defun ez-op-put-prop (operands operand-types)
913 (let* ((obj (car operands))
914 (prop (cadr operands))
915 (a (caddr operands)))
916 (ez-set-obj-prop obj prop a))
919 (defun ez-op-get-prop (operands operand-types)
920 (let* ((obj (car operands))
921 (prop (cadr operands)))
922 (ez-set-var (ez-read-pc-byte-and-inc)
923 (ez-get-obj-prop obj prop)))
926 (defun ez-op-print (operands operand-types)
927 (let* ((word-count-and-string (ez-get-zstring-and-length (ez-get-pc)))
928 (word-count (car word-count-and-string))
929 (string (cdr word-count-and-string)))
931 (ez-increment-pc (* 2 word-count)))
934 (defun ez-op-new-line (operands operand-types)
938 (defun ez-op-print-num (operands operand-types)
939 (let ((s (ez-decode-signed-operand (car operands) (car operand-types))))
940 (ez-print (number-to-string s)))
943 (defun ez-op-print-char (operands operand-types)
944 (let ((c (car operands)))
945 (ez-print (string c)))
948 (defun ez-op-print-obj (operands operand-types)
949 (let ((obj (car operands)))
950 (ez-print (ez-get-obj-name obj)))
953 (defvar ez--next-read-args nil)
954 (defun ez-op-read (operands operand-types)
955 (let ((baddr1 (car operands))
956 (baddr2 (cadr operands)))
957 (setq ez--next-read-args (list baddr1 baddr2)))
960 (defun ez-op-read2 (input-string)
961 (let* ((baddr1 (car ez--next-read-args))
962 (baddr2 (cadr ez--next-read-args)))
964 (dotimes (i (length input-string))
965 (let ((char (elt input-string i)))
966 (ez-mem-set-byte (+ baddr1 1 i) char)))
967 (ez-mem-set-byte (+ baddr1 1 (length input-string)) 0)
969 (ez--tokenize baddr1 baddr2))
972 (defun ez--tokenize (tb-baddr pb-baddr)
980 (let ((next-char (ez-mem-ref-byte (+ tb-baddr 1 token-end))))
984 (setq token-end (- token-end 1))
985 (let* ((text (ez-mem-ref-string (+ tb-baddr 1 token-start)
986 (+ tb-baddr 1 token-end)))
987 (dict-entry (ez-lookup-dictionary text)))
988 (setq token-count (+ token-count 1))
989 (ez-mem-set-word (+ pb-baddr 2 (* token-count 4))
991 (ez-mem-set-bytes (+ pb-baddr 2 (* token-count 4) 2)
994 (setq token-start (+ token-end 1))
995 (setq token-end token-start))
997 ((ez-is-separator char)
998 ;; Add token and separator token
1001 (setq unfinished nil))
1002 (setq token-end (+ token-end 1)))
1007 (defun ez-load-and-run (filename)
1008 (ez-load-file filename)
1010 (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
1014 (defvar ez-machine-state nil
1015 "Identifies the current executation state of the Z-machine.")
1018 (setq ez-machine-state 'run)
1019 (while (eq ez-machine-state 'run)
1020 (setq ez-machine-state (ez-execute-instr))))
1025 (defvar ez-input-marker nil
1026 "Marker for input position in buffer.")
1028 (defun ez-setup-buffer ()
1029 (with-current-buffer (get-buffer-create "*ez*")
1031 (let ((inhibit-read-only t))
1033 (setq-local scroll-conservatively 1)
1034 (if (markerp ez-input-marker)
1035 (set-marker ez-input-marker (point-max))
1036 (setq ez-input-marker (point-max-marker)))
1037 (goto-char (point-max))))
1040 (defun ez-print (string)
1041 (with-current-buffer "*ez*"
1043 (goto-char ez-input-marker)
1044 (insert-before-markers string))))
1048 (if (not (eq ez-machine-state 'wait-for-input))
1049 (error "Z-machine not ready for input."))
1052 (with-current-buffer "*ez*"
1053 (buffer-substring ez-input-marker (point-max))))))
1054 (delete-region ez-input-marker (point-max))
1055 (ez-print (concat input-string "\n"))
1056 (ez-debug-message "\tReceived string \"%s\"" input-string)
1057 (ez-op-read2 input-string)
1062 (defun ez-setup-debug-buffer ()
1063 (with-current-buffer (get-buffer-create "*ez-debug-trace*")
1064 (setq-local buffer-read-only t)
1065 (let ((inhibit-read-only t))
1067 (insert "--- Trace Start ---\n\n"))))
1069 (defun ez-debug-message (&rest strings)
1070 (with-current-buffer (get-buffer-create "*ez-debug-trace*")
1072 (goto-char (point-max))
1073 (let ((inhibit-read-only t))
1074 (insert (apply #'format-message strings) "\n")))))
1076 (defun ez-debug-memory ()
1078 (with-current-buffer (get-buffer-create "*ez-debug-memory*")
1079 (setq-local buffer-read-only t)
1080 (let ((inhibit-read-only t)
1081 (old-point (point)))
1082 (if (eq major-mode 'hexl-mode)
1086 (setq-local buffer-undo-list nil)
1088 (goto-char old-point))))
1093 (let ((map (make-sparse-keymap)))
1094 (define-key map (kbd "RET") 'ez-enter)
1097 (define-derived-mode ez-mode text-mode "ez"
1098 "Major mode for EZ.")
1100 (when (fboundp 'evil-set-initial-state)
1101 (evil-set-initial-state 'ez-mode 'insert))
1104 (interactive "fEnter name of z3 story file: ")
1105 (if (get-buffer "*ez*")
1106 (switch-to-buffer "*ez*")
1107 (switch-to-buffer "*ez*")
1109 (ez-load-and-run zfile))
1115 (ez-setup-debug-buffer)
1116 (ez-load-and-run "zork1.z3"))