1 ;;; ez.el --- Emacs Z-machine
3 ;; Copyright (C) 2021 Tim Vaughan
5 ;; Author: Tim Vaughan <timv@ughan.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/>.
33 (defun ez-decode-signed-bits (n nbits)
34 (if (= 0 (lsh n (- 1 nbits)))
38 (defun ez-decode-signed-byte (b)
39 (ez-decode-signed-bits b 8))
41 (defun ez-decode-signed-word (w)
42 (ez-decode-signed-bits w 16))
44 (defun ez-decode-signed-operand (operand operand-type)
45 (if (eq operand-type 'b)
46 (ez-decode-signed-byte operand)
47 (ez-decode-signed-word operand)))
49 (defun binformat (n &optional s)
53 (new-s (concat (number-to-string (mod n 2)) s)))
56 (binformat d new-s))))
61 "Memory of z-machine.")
63 (defvar ez-version nil)
65 (defvar ez-start-pc nil)
66 (defvar ez-himem-base nil)
67 (defvar ez-dict-base nil)
68 (defvar ez-objtab-addr nil)
69 (defvar ez-abbrevtab-addr nil)
70 (defvar ez-globalvartab-addr nil)
72 (defun ez-mem-ref-byte (addr)
73 (aref ez-memory addr))
75 (defun ez-mem-set-byte (addr val)
76 (aset ez-memory addr val))
78 (defun ez-mem-ref-word (addr)
79 (+ (* 256 (aref ez-memory addr))
80 (aref ez-memory (+ addr 1))))
82 (defun ez-mem-set-word (addr val)
83 (let ((byte-high (/ val 256))
84 (byte-low (mod val 256)))
85 (aset ez-memory addr byte-high)
86 (aset ez-memory (+ addr 1) byte-low)))
88 (defun ez-parse-header ()
89 (setq ez-version (ez-mem-ref-byte #x0))
90 (setq ez-himem-addr (ez-mem-ref-word #x4))
91 (setq ez-start-pc (ez-mem-ref-word #x6))
92 (setq ez-dict-base (ez-mem-ref-word #x8))
93 (setq ez-objtab-addr (ez-mem-ref-word #xA))
94 (setq ez-globalvartab-addr (ez-mem-ref-word #xC))
95 (setq ez-abbrevtab-addr (ez-mem-ref-word #x18)))
97 (defun ez-load-file (filename)
98 "Load story file into memory."
100 (insert-file-contents-literally filename)
101 (setq ez-memory (encode-coding-string (buffer-string) 'raw-text)))
106 (defun ez-get-global-var (gvar)
108 (error "Invalid global variable %d" gvar))
109 (ez-mem-ref-word (+ (* 2 gvar) ez-globalvartab-addr)))
111 (defun ez-set-global-var (gvar val)
112 (ez-mem-set-word (+ (* 2 gvar) ez-globalvartab-addr) val))
116 (defvar ez-property-defaults nil)
118 (defun ez-load-property-defaults ()
119 (setq ez-property-defaults (make-vector 31 0))
121 (aset ez-property-defaults i (aref ez-memory (+ ez-objtab-addr (* 2 i))))))
123 (defun ez-get-obj-addr (obj)
124 (+ ez-objtab-addr (* 2 31) (* 9 (- obj 1))))
126 (defun ez-get-obj-parent (obj)
127 (let ((addr (ez-get-obj-addr obj)))
128 (ez-mem-ref-byte (+ addr 4))))
130 (defun ez-set-obj-parent (obj new-parent)
131 (let ((addr (ez-get-obj-addr obj)))
132 (ez-mem-set-byte (+ addr 4) new-parent)))
134 (defun ez-get-obj-sibling (obj)
135 (let ((addr (ez-get-obj-addr obj)))
136 (ez-mem-ref-byte (+ addr 5))))
138 (defun ez-set-obj-sibling (obj new-sibling)
139 (let ((addr (ez-get-obj-addr obj)))
140 (ez-mem-set-byte (+ addr 5) new-sibling)))
142 (defun ez-get-obj-child (obj)
143 (let ((addr (ez-get-obj-addr obj)))
144 (ez-mem-ref-byte (+ addr 6))))
146 (defun ez-set-obj-child (obj new-child)
147 (let ((addr (ez-get-obj-addr obj)))
148 (ez-mem-set-byte (+ addr 6) new-child)))
150 (defun ez-get-obj-plist-addr (obj)
151 (let ((addr (ez-get-obj-addr obj)))
152 (ez-mem-ref-word (+ addr 7))))
154 (defun ez-get-obj-name (obj)
155 (let ((plist-addr (ez-get-obj-plist-addr obj)))
156 (if (> (ez-mem-ref-byte plist-addr) 0)
157 (ez-get-zstring (+ 1 (ez-get-obj-plist-addr obj)))
160 (defun ez-get-prop-default (prop)
161 (ez-mem-ref-word (+ ez-objtab-addr (* 2 (+ 1 prop)))))
163 (defun ez-get-prop-len (prop-size-byte)
164 (lsh prop-size-byte -5))
166 (defun ez-get-prop-num (prop-size-byte)
167 (logand #b00011111 prop-size-byte))
169 (defun ez-get-obj-prop-addr (obj prop)
170 (let* ((plist-addr (ez-get-obj-plist-addr obj))
171 (prop-addr (+ plist-addr 1 (* 2 (ez-mem-ref-byte plist-addr))))
172 (size-byte (ez-mem-ref-byte prop-addr)))
173 (while (not (or (= size-byte 0)
174 (= prop (ez-get-prop-num size-byte))))
175 (setq prop-addr (+ prop-addr (ez-get-prop-len size-byte) 2)
176 size-byte (ez-mem-ref-byte prop-addr)))
179 (defun ez-get-obj-prop (obj prop)
180 (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
181 (size-byte (ez-mem-ref-byte prop-addr)))
183 (ez-get-prop-default prop)
184 (let ((prop-len (ez-get-prop-len size-byte))
185 (data-addr (+ prop-addr 1)))
188 (ez-mem-ref-byte data-addr))
190 (ez-mem-ref-word data-addr)))))))
192 (defun ez-set-obj-prop (obj prop value)
193 (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
194 (size-byte (ez-mem-ref-byte prop-addr)))
197 (error "Tried to set non-existant property"))
198 ((= (ez-get-prop-len size-byte) 1)
199 (ez-mem-set-byte (+ prop-addr 1) value))
201 (ez-mem-set-word (+ prop-addr 1) value)))))
203 (defun ez-get-obj-attr (obj attr)
204 (let* ((byte-num (/ attr 8))
205 (bit-num (mod attr 8))
206 (bit-mask (lsh 1 (- 7 bit-num))))
207 (if (> (logand bit-mask (ez-mem-ref-byte (+ (ez-get-obj-addr obj) byte-num))) 0)
211 (defun ez-set-obj-attr (obj attr val)
212 (let* ((byte-num (/ attr 8))
213 (bit-num (mod attr 8))
214 (bit-mask (lsh 1 (- 7 bit-num)))
215 (byte-addr (+ (ez-get-obj-addr obj) byte-num))
216 (byte (ez-mem-ref-byte byte-addr))
217 (current-set (> (logand bit-mask byte) 0)))
218 (if (or (and current-set (= val 0))
219 (and (not current-set) (> val 0)))
220 (ez-mem-set-byte byte-addr (logxor byte bit-mask)))))
223 (defun ez-remove-obj (obj)
224 (let ((parent (ez-get-obj-parent obj))
225 (sibling (ez-get-obj-sibling obj)))
227 (let ((child (ez-get-obj-child parent)))
229 (ez-set-obj-child parent sibling)
230 (while (not (= obj (ez-get-obj-sibling child)))
231 (setq child (ez-get-obj-sibling child)))
232 (ez-set-obj-sibling child (ez-get-obj-sibling obj))))
233 (ez-set-obj-parent obj 0))
234 (ez-set-obj-sibling obj 0)))
236 (defun ez-insert-obj (obj new-parent)
238 (unless (= new-parent 0)
239 (ez-set-obj-sibling obj (ez-get-obj-child new-parent))
240 (ez-set-obj-child new-parent obj)))
244 (defvar ez-zstring-alphabets
247 (list " abcdefghijklmnopqrstuvwxyz"
248 " ABCDEFGHIJKLMNOPQRSTUVWXYZ"
249 " \n0123456789.,!?_#'\"/\\-:()")
250 "Alphabets used by V3")
252 (defun ez-parse-zstring-word (word)
254 (logand (lsh word -10) #b11111)
255 (logand (lsh word -5) #b11111)
256 (logand word #b11111)))
258 (defun ez-get-zstring-chars-and-length (base-addr)
259 (let ((addr base-addr)
264 (let ((components (ez-parse-zstring-word (ez-mem-ref-word addr))))
265 (setq chars (append chars (cdr components)))
266 (setq addr (+ addr 2))
267 (setq word-count (+ word-count 1))
268 (when (= (car components) 1)
269 (setq not-done nil))))
270 (cons word-count chars)))
272 (defun ez-get-zstring-and-length (base-addr)
273 (let* ((word-count-and-chars (ez-get-zstring-chars-and-length base-addr))
274 (word-count (car word-count-and-chars))
275 (chars (cdr word-count-and-chars))
284 (* 2 (ez-mem-ref-word (+ ez-abbrevtab-addr
285 (* 2 (+ (* (- abbrev-char 1) 32) char)))))))
286 (setq s (concat s (cdr (ez-get-zstring-and-length abbrev-addr)))))
287 (setq abbrev-char nil))
288 ((memq char '(1 2 3)) ;Abbreviation
289 (setq abbrev-char char))
291 (setq cur (mod (+ cur 1) 3)))
293 (setq cur (mod (+ 3 (- cur 1)) 3)))
295 (setq s (concat s (substring (elt ez-zstring-alphabets cur)
298 (cons word-count s)))
300 (defun ez-get-zstring (base-addr)
301 (cdr (ez-get-zstring-and-length base-addr)))
306 (defvar ez-call-stack nil)
308 (defun ez-make-call-stack-frame (pc &optional call-method)
314 (defun ez-add-call-stack-frame (pc &optional call-method)
315 (push (ez-make-call-stack-frame pc call-method) ez-call-stack))
317 (defun ez-pop-call-stack-frame ()
320 (defun ez-routine-stack ()
321 (elt (car ez-call-stack) 1))
323 (defun ez-routine-stack-push (val)
324 (let ((frame (car ez-call-stack)))
325 (setf (elt frame 1) (cons val (elt frame 1)))))
327 (defun ez-routine-stack-pop ()
328 (let* ((frame (car ez-call-stack))
329 (rs-head (car (elt frame 1))))
330 (setf (elt frame 1) (cdr (elt frame 1)))
333 (defun ez-get-local-var (lvar)
334 (let ((frame (car ez-call-stack)))
335 (aref (elt frame 2) (- lvar 1))))
337 (defun ez-set-local-var (lvar val)
338 (let ((frame (car ez-call-stack)))
339 (aset (elt frame 2) (- lvar 1) val)))
342 (caar ez-call-stack))
344 (defun ez-set-pc (new-pc)
345 (setf (car (car ez-call-stack)) new-pc))
347 (defun ez-increment-pc (inc)
348 (ez-set-pc (+ (ez-get-pc) inc)))
350 (defun ez-read-pc-byte-and-inc ()
351 (let ((res (ez-mem-ref-byte (ez-get-pc))))
355 (defun ez-read-pc-word-and-inc ()
356 (let ((res (ez-mem-ref-word (ez-get-pc))))
360 ;; Instruction execution
362 (defun ez-get-var (var)
365 (ez-routine-stack-pop))
367 (ez-get-local-var var))
369 (ez-get-global-var (- var 16)))))
371 (defun ez-set-var (var val)
374 (ez-routine-stack-push val))
376 (ez-set-local-var var val))
378 (ez-set-global-var (- var 16) val))))
380 (defun ez-read-pc-var-and-inc ()
381 (ez-get-var (ez-read-pc-byte-and-inc)))
383 (defun ez-execute-instr ()
384 (let ((instr-pc (ez-get-pc))
385 (opbyte (ez-read-pc-byte-and-inc))
386 (optype) (opcode) (operands))
388 ((<= #x0 opbyte #x1f)
391 operands (list (ez-read-pc-byte-and-inc)
392 (ez-read-pc-byte-and-inc))
393 operand-types '(b b)))
394 ((<= #x20 opbyte #x3F)
396 opcode (- opbyte #x20)
397 operands (list (ez-read-pc-byte-and-inc)
398 (ez-read-pc-var-and-inc))
399 operand-types '(b w)))
400 ((<= #x40 opbyte #x5F)
402 opcode (- opbyte #x40)
403 operands (list (ez-read-pc-var-and-inc)
404 (ez-read-pc-byte-and-inc))
405 operand-types '(w b)))
406 ((<= #x60 opbyte #x7F)
408 opcode (- opbyte #x60)
409 operands (list (ez-read-pc-var-and-inc)
410 (ez-read-pc-var-and-inc))
411 operand-types '(w w)))
412 ((<= #x80 opbyte #x8F)
414 opcode (- opbyte #x80)
415 operands (list (ez-read-pc-word-and-inc))
417 ((<= #x90 opbyte #x9F)
419 opcode (- opbyte #x90)
420 operands (list (ez-read-pc-byte-and-inc))
422 ((<= #xA0 opbyte #xAF)
424 opcode (- opbyte #xa0)
425 operands (list (ez-read-pc-var-and-inc))
427 ((<= #xB0 opbyte #xBF)
429 opcode (- opbyte #xb0)
432 ((<= #xC0 opbyte #xDF)
434 opcode (- opbyte #xc0))
435 (let ((operands-and-types (ez-read-var-operands-and-inc)))
436 (setq operands (car operands-and-types)
437 operand-types (cdr operands-and-types))))
438 ((<= #xE0 opbyte #xFF)
440 opcode (- opbyte #xe0))
441 (let ((operands-and-types (ez-read-var-operands-and-inc)))
442 (setq operands (car operands-and-types)
443 operand-types (cdr operands-and-types)))))
444 (let ((table-row (assoc (list optype opcode) ez-op-table)))
446 (error "Unsupported op PC:%x Optype:%s Opcode:%x Operands:%s Operand-types:%s"
447 instr-pc optype opcode operands operand-types))
448 (let ((mnemonic (elt table-row 1)))
449 (message "PC:%x Optype:%s Opcode:%x Mnemonic:%s Operands:%s Operand-types:%s"
450 instr-pc optype opcode mnemonic operands operand-types))
451 (funcall (elt table-row 2) operands operand-types))))
453 (defun ez-read-var-operands-and-inc ()
454 (let* ((type-byte (ez-read-pc-byte-and-inc))
455 (types (let ((type1 (lsh type-byte -6)))
459 (let ((type2 (lsh (logand #b110000 type-byte) -4)))
463 (let ((type3 (lsh (logand #b1100 type-byte) -2)))
467 (let ((type4 (logand #b11)))
470 (list type4))))))))))))))
475 ((= type 0) (ez-read-pc-word-and-inc))
476 ((= type 1) (ez-read-pc-byte-and-inc))
477 ((= type 2) (ez-read-pc-var-and-inc))))
488 (defun ez-do-branch (branch)
489 (let* ((branch-byte (ez-read-pc-byte-and-inc))
490 (invert (= 0 (logand branch-byte #b10000000)))
491 (single-byte (> (logand branch-byte #b01000000) 0))
494 (logand branch-byte #b00111111)
495 (let ((pos (= (logand branch-byte #b00100000) 0))
496 (val (+ (* 256 (logand branch-byte #b00011111))
497 (ez-read-pc-byte-and-inc))))
501 (if (or (and branch (not invert))
502 (and (not branch) invert))
509 (ez-set-pc (+ (ez-get-pc) offset -2)))))))
514 '(((0op #x00) rtrue ez-op-rtrue)
515 ((0op #x01) rfalse ez-op-rfalse)
516 ((1op #x00) jz ez-op-jz)
517 ((1op #x05) inc ez-op-inc)
518 ((1op #x06) dec ez-op-dec)
519 ((1op #x0B) ret ez-op-ret)
520 ((1op #x0C) jump ez-op-jump)
521 ((2op #x05) inc_jg ez-op-inc-jg)
522 ((2op #x04) dec_jg ez-op-dec-jg)
523 ((2op #x0D) store ez-op-store)
524 ((1op #x0E) load ez-op-load)
525 ((var #x01) storew ez-op-storew)
526 ((2op #x0F) loadw ez-op-loadw)
527 ((var #x02) storeb ez-op-storeb)
528 ((2op #x10) loadb ez-op-loadb)
529 ((2op #x01) je ez-op-je)
530 ((2op #x02) jl ez-op-jl)
531 ((2op #x06) jin ez-op-jin)
532 ((2op #x08) or ez-op-or)
533 ((2op #x09) and ez-op-and)
534 ((2op #x14) add ez-op-add)
535 ((2op #x15) sub ez-op-sub)
536 ((2op #x16) mul ez-op-mul)
537 ((2op #x17) div ez-op-div)
538 ((2op #x18) mod ez-op-mod)
539 ((var #x00) call_fv ez-op-callf)
540 ((1op #x01) get_sibling ez-op-get-sibling)
541 ((1op #x02) get_child ez-op-get-child)
542 ((1op #x03) get_parent ez-op-get-parent)
543 ((2op #x0A) test_attr ez-op-test-attr)
544 ((2op #x0B) set_attr ez-op-set-attr)
545 ((2op #x0C) clear_attr ez-op-clear-attr)
546 ((1op #x09) remove_obj ez-op-remove-obj)
547 ((2op #x0E) insert_obj ez-op-insert-obj)
548 ((var #x03) put_prop ez-op-put-prop)
549 ((2op #x11) get_prop ez-op-get-prop)
550 ((0op #x02) print ez-op-print)
551 ((0op #x0B) new_line ez-op-new-line)
552 ((var #x06) print_num ez-op-print-num)
553 ((var #x05) print_char ez-op-print-char)
554 ((1op #x0A) print_obj ez-op-print-obj)))
556 (defun ez-op-ret (operands &optional operand-types)
557 (let ((retval (car operands)))
558 (ez-pop-call-stack-frame)
559 (ez-set-var (ez-read-pc-byte-and-inc) retval))
562 (defun ez-op-rtrue (&optional operands operand-types)
566 (defun ez-op-rfalse (&optional operands operand-types)
570 (defun ez-op-jz (operands operand-types)
571 (ez-do-branch (= (car operands) 0))
574 (defun ez-op-je (operands operand-types)
575 (ez-do-branch (memq (car operands) (cdr operands)))
578 (defun ez-op-jg (operands operand-types)
579 (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
580 (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
581 (ez-do-branch (> s1 s2)))
584 (defun ez-op-jl (operands operand-types)
585 (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
586 (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
587 (ez-do-branch (< s1 s2)))
590 (defun ez-op-inc-jg (operands operand-types)
591 (let ((var (car operands)))
592 (ez-op-inc (list var))
593 (ez-op-jg (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
596 (defun ez-op-dec-jl (operands operand-types)
597 (let ((var (car operands)))
598 (ez-op-dec (list var))
599 (ez-op-jl (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
602 (defun ez-op-jin (operands operand-types)
603 (let ((obj (car operands))
605 (ez-do-branch (or (= n 0)
606 (= n (ez-get-obj-parent obj)))))
609 (defun ez-op-jump (operands operand-types)
610 (let ((offset (if (eq (car operand-types) 'b)
611 (ez-decode-signed-byte (car operands))
612 (ez-decode-signed-word (car operands)))))
613 (ez-set-pc (+ (ez-get-pc) offset -2)))
616 (defun ez-op-inc (operands &optional operand-types)
617 (let ((var (car operands)))
618 (ez-set-var var (mod (+ 1 (ez-get-var var)) #x10000)))
621 (defun ez-op-dec (operands &optional operand-types)
622 (let ((var (car operands)))
623 (ez-set-var var (mod (+ (ez-get-var var) 1) #x10000)))
626 (defun ez-op-store (operands operand-types)
627 (let ((var (car operands))
632 (defun ez-op-load (operands operand-types)
633 (let ((var (car operands)))
634 (ez-set-var (ez-read-pc-byte-and-inc) (ez-get-var var)))
637 (defun ez-op-storew (operands operand-types)
638 (let ((baddr (car operands))
640 (a (caddr operands)))
641 (ez-mem-set-word (+ baddr (* 2 n)) a))
644 (defun ez-op-loadw (operands operand-types)
645 (let ((baddr (car operands))
647 (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-word (+ baddr (* 2 n)))))
650 (defun ez-op-storeb (operands operand-types)
651 (let ((baddr (car operands))
653 (a (caddr operands)))
654 (ez-mem-set-byte (+ baddr n) a))
657 (defun ez-op-loadb (operands operand-types)
658 (let ((baddr (car operands))
660 (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-byte (+ baddr n))))
663 (defun ez-op-and (operands operand-types)
664 (let ((a (car operands))
666 (ez-set-var (ez-read-pc-byte-and-inc) (logand a b)))
669 (defun ez-op-or (operands operand-types)
670 (let ((a (car operands))
672 (ez-set-var (ez-read-pc-byte-and-inc) (logior a b)))
675 (defun ez-op-add (operands operand-types)
676 (let ((a (car operands))
678 (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ a b) #x10000)))
681 (defun ez-op-sub (operands operand-types)
682 (let ((a (car operands))
684 (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ (- a b) #x10000) #x10000)))
687 (defun ez-op-mul (a b)
688 (let ((a (car operands))
690 (ez-set-var (ez-read-pc-byte-and-inc) (mod (* a b) #x10000)))
693 (defun ez-op-div (a b)
694 (error "Not implemented"))
696 (defun ez-op-mod (a b)
697 (error "Not implemented"))
699 (defun ez-op-callf (operands operand-types)
700 (let* ((raddr (car operands))
701 (call-operands (cdr operands))
703 (L (ez-mem-ref-byte r))
704 (n (length call-operands))
705 (new-pc (+ r 1 (* L 2))))
706 (ez-add-call-stack-frame new-pc)
709 (ez-set-local-var (+ i 1) (elt call-operands i))
710 (ez-set-local-var (+ i 1) (ez-mem-ref-word (+ r 1 (* 2 i)))))))
713 (defun ez-op-test-attr (operands operand-types)
714 (let ((obj (car operands))
715 (attr (cadr operands)))
716 (ez-do-branch (= 1 (ez-get-obj-attr obj attr)))
719 (defun ez-op-set-attr (operands operand-types)
720 (let ((obj (car operands))
721 (attr (cadr operands)))
722 (ez-set-obj-attr obj attr 1))
725 (defun ez-op-clear-attr (operands operand-types)
726 (let ((obj (car operands))
727 (attr (cadr operands)))
728 (ez-set-obj-attr obj attr 0))
731 (defun ez-op-get-sibling (operands operand-types)
732 (let ((sib (ez-get-obj-sibling (car operands))))
733 (ez-set-var (ez-read-pc-byte-and-inc) sib)
734 (ez-do-branch (> sib 0)))
737 (defun ez-op-get-child (operands operand-types)
738 (let ((child (ez-get-obj-child (car operands))))
739 (ez-set-var (ez-read-pc-byte-and-inc) child)
740 (ez-do-branch (> child 0)))
743 (defun ez-op-get-parent (operands operand-types)
744 (let ((parent (ez-get-obj-parent (car operands))))
745 (ez-set-var (ez-read-pc-byte-and-inc) parent))
748 (defun ez-op-remove-obj (operands operand-types)
749 (let ((obj (car operands)))
753 (defun ez-op-insert-obj (operands operand-types)
754 (let ((obj1 (car operands))
755 (obj2 (cadr operands)))
756 (ez-insert-obj obj1 obj2))
759 (defun ez-op-put-prop (operands operand-types)
760 (let* ((obj (car operands))
761 (prop (cadr operands))
762 (a (caddr operands)))
763 (ez-set-obj-prop obj prop a))
766 (defun ez-op-get-prop (operands operand-types)
767 (let* ((obj (car operands))
768 (prop (cadr operands)))
769 (ez-set-var (ez-read-pc-byte-and-inc)
770 (ez-get-obj-prop obj prop)))
773 (defun ez-op-print (operands operand-types)
774 (let* ((word-count-and-string (ez-get-zstring-and-length (ez-get-pc)))
775 (word-count (car word-count-and-string))
776 (string (cdr word-count-and-string)))
778 (ez-increment-pc (* 2 word-count)))
781 (defun ez-op-new-line (operands operand-types)
785 (defun ez-op-print-num (operands operand-types)
786 (let ((s (ez-decode-signed-operand (car operands) (car operand-types))))
787 (ez-print (number-to-string s)))
790 (defun ez-op-print-char (operands operand-types)
791 (let ((c (car operands)))
792 (ez-print (string c)))
795 (defun ez-op-print-obj (operands operand-types)
796 (let ((obj (car operands)))
797 (ez-print (ez-get-obj-name obj)))
802 (defun ez-run (filename)
803 (ez-load-file filename)
805 (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
807 (while (ez-execute-instr)))
813 (defun ez-render-prompt ()
814 (with-current-buffer "*ez*"
815 (let ((update-point (= ez-input-marker (point)))
816 (update-window-points (mapcar (lambda (w)
817 (list (= (window-point w) ez-input-marker)
819 (get-buffer-window-list nil nil t))))
821 (set-marker-insertion-type ez-prompt-marker nil)
822 (set-marker-insertion-type ez-input-marker t)
823 (let ((inhibit-read-only t))
824 (delete-region ez-prompt-marker ez-input-marker)
825 (goto-char ez-prompt-marker)
828 (propertize " " ; Need this to be separate to mark it as rear-nonsticky
831 (set-marker-insertion-type ez-input-marker nil))
832 (goto-char ez-input-marker))))
834 (defvar ez-prompt-marker nil
835 "Marker for prompt position in buffer.")
837 (defvar ez-input-marker nil
838 "Marker for prompt position in buffer.")
840 (defun ez-setup-buffer ()
841 (with-current-buffer (get-buffer-create "*ez*")
842 (let ((inhibit-read-only t))
843 (delete-region (point-min) (point-max)))
844 (setq-local scroll-conservatively 1)
845 (if (markerp ez-prompt-marker)
846 (set-marker ez-prompt-marker (point-max))
847 (setq ez-prompt-marker (point-max-marker)))
848 (if (markerp ez-input-marker)
849 (set-marker ez-input-marker (point-max))
850 (setq ez-input-marker (point-max-marker)))
851 (goto-char (point-max))
855 (defun ez-print (string)
856 (with-current-buffer "*ez*"
858 (goto-char ez-prompt-marker)
859 (insert-before-markers string))))
864 (let ((map (make-sparse-keymap)))
865 (define-key map (kbd "RET") 'ez-enter)
868 (define-derived-mode ez-mode text-mode "ez"
869 "Major mode for EZ.")
871 (when (fboundp 'evil-set-initial-state)
872 (evil-set-initial-state 'ez-mode 'insert))
875 (interactive "fEnter name of z3 story file: ")
876 (if (get-buffer "*ez*")
877 (switch-to-buffer "*ez*")
878 (switch-to-buffer "*ez*")
886 (switch-to-buffer "*ez*")