;;; ez.el --- Emacs Z-machine
-;; Copyright (C) 2021 Tim Vaughan
+;; Copyright (C) 2021,2022,2023 Tim Vaughan
;; Author: Tim Vaughan <timv@ughan.xyz>
;; Created: 13 Oct 2021
;;; Commentary:
+;; There are many Z-machine interpreters, but this one is mine.
+;; It only capable of interpreting the subset of Z-code necessary
+;; to run the first Zork game in z3 format.
+;;
+;; It is based entirely on the description of the Z-machine contained
+;; Marnix Klooster's wonderful document, "The Z-machine And How to Emulate It."
+
;;; Code:
;; Utility functions
(defun ez-decode-signed-word (w)
(ez-decode-signed-bits w 16))
+(defun ez-decode-signed-operand (operand operand-type)
+ (if (eq operand-type 'b)
+ (ez-decode-signed-byte operand)
+ (ez-decode-signed-word operand)))
+
(defun binformat (n &optional s)
(unless s
(setq s ""))
new-s
(binformat d new-s))))
+(defun ez-list-to-string-hex (l)
+ (concat "("
+ (when l
+ (concat
+ (format "%x" (car l))
+ (apply 'concat (mapcar (lambda (n) (format " %x" n)) (cdr l)))))
+ ")"))
+
;; Memory
(defvar ez-memory nil
(defvar ez-start-pc nil)
(defvar ez-himem-base nil)
-(defvar ez-dict-addr nil)
+(defvar ez-dict-base nil)
(defvar ez-objtab-addr nil)
(defvar ez-abbrevtab-addr nil)
(defvar ez-globalvartab-addr nil)
+(defvar ez-dict-entries nil
+ "Parsed dictionary")
+
+(defvar ez-dict-separators nil
+ "Parsed dictionary")
+
(defun ez-mem-ref-byte (addr)
(aref ez-memory addr))
"Load story file into memory."
(with-temp-buffer
(insert-file-contents-literally filename)
- (setq ez-memory (encode-coding-string (buffer-string) 'raw-text))))
+ (setq ez-memory (encode-coding-string (buffer-string) 'raw-text)))
+ 'done)
;; Global variables
(defun ez-get-global-var (gvar)
- (ez-mem-ref-word (+ (* 2 gvar) (ez-mem-ref-word ez-globalvartab-addr))))
+ (if (> gvar 239)
+ (error "Invalid global variable %d" gvar))
+ (let ((val
+ (ez-mem-ref-word (+ (* 2 gvar) ez-globalvartab-addr))))
+ (ez-debug-message "\tRetrieved %x from global variable %x" val gvar)
+ val))
(defun ez-set-global-var (gvar val)
- (ez-mem-set-word (+ (* 2 gvar) (ez-mem-ref-word ez-globalvartab-addr)) val))
+ (ez-mem-set-word (+ (* 2 gvar) ez-globalvartab-addr) val)
+ (ez-debug-message "\tSet global variabl %x to %x" gvar val))
;; Object tree
-(defun ez-make-obj (&optional name attribs props parent first-child next-sibling)
- (list name attribs props parent first-child next-sibling))
-
-(defun ez-obj-name (obj) (elt obj 0))
-(defun ez-obj-attribs (obj) (elt obj 1))
-(defun ez-obj-props (obj) (elt obj 2))
-(defun ez-obj-parent (obj) (elt obj 3))
-(defun ez-obj-first-child (obj) (elt obj 4))
-(defun ez-obj-next-sibling (obj) (elt obj 5))
-
(defvar ez-property-defaults nil)
(defun ez-load-property-defaults ()
(dotimes (i 31)
(aset ez-property-defaults i (aref ez-memory (+ ez-objtab-addr (* 2 i))))))
-(defun ez-get-obj (obj-id)
- (let ((addr (+ ez-objtab-addr
- (* 2 31)
- (* 9 (- obj-id 1)))))
- (list
- obj-id
- (ez-mem-ref-byte (+ addr 4))
- (ez-mem-ref-byte (+ addr 5))
- (ez-mem-ref-byte (+ addr 6))
- (ez-mem-ref-word (+ addr 7))
- (let ((plist-addr (ez-mem-ref-word (+ addr 7))))
- (if (> (ez-mem-ref-byte plist-addr) 0)
- (ez-get-zstring (+ 1 plist-addr))
- "")))))
-
+(defun ez-get-obj-addr (obj)
+ (+ ez-objtab-addr (* 2 31) (* 9 (- obj 1))))
+
+(defun ez-get-obj-parent (obj)
+ (let ((addr (ez-get-obj-addr obj)))
+ (ez-mem-ref-byte (+ addr 4))))
+
+(defun ez-set-obj-parent (obj new-parent)
+ (let ((addr (ez-get-obj-addr obj)))
+ (ez-mem-set-byte (+ addr 4) new-parent)))
+
+(defun ez-get-obj-sibling (obj)
+ (let ((addr (ez-get-obj-addr obj)))
+ (ez-mem-ref-byte (+ addr 5))))
+
+(defun ez-set-obj-sibling (obj new-sibling)
+ (let ((addr (ez-get-obj-addr obj)))
+ (ez-mem-set-byte (+ addr 5) new-sibling)))
+
+(defun ez-get-obj-child (obj)
+ (let ((addr (ez-get-obj-addr obj)))
+ (ez-mem-ref-byte (+ addr 6))))
+
+(defun ez-set-obj-child (obj new-child)
+ (let ((addr (ez-get-obj-addr obj)))
+ (ez-mem-set-byte (+ addr 6) new-child)))
+
+(defun ez-get-obj-plist-addr (obj)
+ (let ((addr (ez-get-obj-addr obj)))
+ (ez-mem-ref-word (+ addr 7))))
+
+(defun ez-get-obj-name (obj)
+ (let ((plist-addr (ez-get-obj-plist-addr obj)))
+ (if (> (ez-mem-ref-byte plist-addr) 0)
+ (ez-get-zstring (+ 1 (ez-get-obj-plist-addr obj)))
+ nil)))
+
+(defun ez-get-prop-default (prop)
+ (ez-mem-ref-word (+ ez-objtab-addr (* 2 (+ 1 prop)))))
+
+(defun ez-get-prop-len (prop-size-byte)
+ (lsh prop-size-byte -5))
+
+(defun ez-get-prop-num (prop-size-byte)
+ (logand #b00011111 prop-size-byte))
+
+(defun ez-get-obj-prop-addr (obj prop)
+ (let* ((plist-addr (ez-get-obj-plist-addr obj))
+ (prop-addr (+ plist-addr 1 (* 2 (ez-mem-ref-byte plist-addr))))
+ (size-byte (ez-mem-ref-byte prop-addr)))
+ (while (not (or (= size-byte 0)
+ (= prop (ez-get-prop-num size-byte))))
+ (setq prop-addr (+ prop-addr (ez-get-prop-len size-byte) 2)
+ size-byte (ez-mem-ref-byte prop-addr)))
+ prop-addr))
+
+(defun ez-get-obj-prop (obj prop)
+ (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
+ (size-byte (ez-mem-ref-byte prop-addr)))
+ (if (= size-byte 0)
+ (ez-get-prop-default prop)
+ (let ((prop-len (ez-get-prop-len size-byte))
+ (data-addr (+ prop-addr 1)))
+ (cond
+ ((= prop-len 0)
+ (ez-mem-ref-byte data-addr))
+ ((>= prop-len 1)
+ (ez-mem-ref-word data-addr)))))))
+
+(defun ez-set-obj-prop (obj prop value)
+ (let* ((prop-addr (ez-get-obj-prop-addr obj prop))
+ (size-byte (ez-mem-ref-byte prop-addr)))
+ (cond
+ ((= size-byte 0)
+ (error "Tried to set non-existant property"))
+ ((= (ez-get-prop-len size-byte) 1)
+ (ez-mem-set-byte (+ prop-addr 1) value))
+ (t
+ (ez-mem-set-word (+ prop-addr 1) value)))))
+
+(defun ez-get-obj-attr (obj attr)
+ (let* ((byte-num (/ attr 8))
+ (bit-num (mod attr 8))
+ (bit-mask (lsh 1 (- 7 bit-num))))
+ (if (> (logand bit-mask (ez-mem-ref-byte (+ (ez-get-obj-addr obj) byte-num))) 0)
+ 1
+ 0)))
+
+(defun ez-set-obj-attr (obj attr val)
+ (let* ((byte-num (/ attr 8))
+ (bit-num (mod attr 8))
+ (bit-mask (lsh 1 (- 7 bit-num)))
+ (byte-addr (+ (ez-get-obj-addr obj) byte-num))
+ (byte (ez-mem-ref-byte byte-addr))
+ (current-set (> (logand bit-mask byte) 0)))
+ (if (or (and current-set (= val 0))
+ (and (not current-set) (> val 0)))
+ (ez-mem-set-byte byte-addr (logxor byte bit-mask)))))
+
+
+(defun ez-remove-obj (obj)
+ (let ((parent (ez-get-obj-parent obj))
+ (sibling (ez-get-obj-sibling obj)))
+ (unless (= parent 0)
+ (let ((child (ez-get-obj-child parent)))
+ (if (= child obj)
+ (ez-set-obj-child parent sibling)
+ (while (not (= obj (ez-get-obj-sibling child)))
+ (setq child (ez-get-obj-sibling child)))
+ (ez-set-obj-sibling child (ez-get-obj-sibling obj))))
+ (ez-set-obj-parent obj 0))
+ (ez-set-obj-sibling obj 0)))
+
+(defun ez-insert-obj (obj new-parent)
+ (ez-remove-obj obj)
+ (unless (= new-parent 0)
+ (ez-set-obj-sibling obj (ez-get-obj-child new-parent))
+ (ez-set-obj-child new-parent obj)))
;; Z-strings
(logand (lsh word -5) #b11111)
(logand word #b11111)))
-(defun ez-get-zstring-chars (base-addr)
+(defun ez-get-zstring-chars-and-length (base-addr)
(let ((addr base-addr)
(chars nil)
- (not-done t))
+ (not-done t)
+ (word-count 0))
(while not-done
(let ((components (ez-parse-zstring-word (ez-mem-ref-word addr))))
(setq chars (append chars (cdr components)))
(setq addr (+ addr 2))
+ (setq word-count (+ word-count 1))
(when (= (car components) 1)
(setq not-done nil))))
- chars))
+ (cons word-count chars)))
+
+(defun ez-get-zstring-and-length (base-addr)
+ (let* ((word-count-and-chars (ez-get-zstring-chars-and-length base-addr))
+ (word-count (car word-count-and-chars))
+ (chars (cdr word-count-and-chars))
+ (cur 0)
+ (lock 0)
+ (s ""))
+ (while (> (length chars) 0)
+ (let ((char (pop chars)))
+ (cond
+ ((memq char '(1 2 3)) ;Abbreviation
+ (let* ((abbrev-char char)
+ (abbrev-addr
+ (* 2 (ez-mem-ref-word (+ ez-abbrevtab-addr
+ (* 2 (+ (* (- abbrev-char 1) 32) (pop chars))))))))
+ (setq s (concat s (cdr (ez-get-zstring-and-length abbrev-addr))))))
+ ((= char 4)
+ (setq cur (mod (+ cur 1) 3)))
+ ((= char 5)
+ (setq cur (mod (+ 3 (- cur 1)) 3)))
+ ((and (= cur 2) (= char 6))
+ (setq s (concat s (char-to-string (+ (lsh (pop chars) 5) (pop chars)))))
+ (setq cur lock))
+ (t
+ (setq s (concat s (substring (elt ez-zstring-alphabets cur)
+ char (+ char 1))))
+ (setq cur lock)))))
+ (cons word-count s)))
(defun ez-get-zstring (base-addr)
- (let ((chars (ez-get-zstring-chars base-addr))
- (cur 0)
- (lock 0)
- (abbrev-char nil)
- (s ""))
- (dolist (char chars)
- (cond
- (abbrev-char
- (let ((abbrev-addr
- (* 2 (ez-mem-ref-word (+ ez-abbrevtab-addr
- (* 2 (+ (* (- abbrev-char 1) 32) char)))))))
- (setq s (concat s (ez-get-zstring abbrev-addr))))
- (setq abbrev-char nil))
- ((memq char '(1 2 3)) ;Abbreviation
- (setq abbrev-char char))
- ((= char 4)
- (setq cur (mod (+ cur 1) 2)))
- ((= char 5)
- (setq cur (mod (+ 2 (- cur 1)) 2)))
- (t
- (setq s (concat s (substring (elt ez-zstring-alphabets cur)
- char (+ char 1))))
- (setq cur lock))))
- s))
-
+ (cdr (ez-get-zstring-and-length base-addr)))
+
+(defun ez-encode (string)
+ "Encodes a string as a 2-word 5-padded Z-string.
+Used for matching input with dictionary entries when tokenizing."
+ (let ((chars
+ (mapcan
+ (lambda (c)
+ (cond
+ ((seq-contains-p (elt ez-zstring-alphabets 0) c)
+ (list (seq-position (elt ez-zstring-alphabets 0) c)))
+ ((seq-contains-p (elt ez-zstring-alphabets 1) c)
+ (list 4 (seq-position (elt ez-zstring-alphabets 1) c)))
+ ((seq-contains-p (elt ez-zstring-alphabets 2) c)
+ (list 5 (seq-position (elt ez-zstring-alphabets 2) c)))
+ (t
+ (list 5 6 (lsh c -5) (logand c #b11111)))))
+ string)))
+ (if (< (length chars) 6)
+ (append chars (make-list (- 6 (length chars)) 5))
+ (take 6 chars))))
+
+;; Dictionary
+
+(defun ez-parse-dictionary ()
+ (let* ((nseps (ez-mem-ref-byte ez-dict-base))
+ (separators
+ (mapcar (lambda (i) (ez-mem-ref-byte (+ ez-dict-base i)))
+ (number-sequence 1 nseps)))
+ (bytes-per-entry (ez-mem-ref-byte (+ ez-dict-base 1 nseps)))
+ (nentries (ez-mem-ref-word (+ ez-dict-base 2 nseps)))
+ (entries-base (+ ez-dict-base nseps 4))
+ (entries nil))
+ (dotimes (i nentries)
+ (let ((this-base (+ entries-base (* 7 i))))
+ (setq entries (cons (cons (ez-get-zstring this-base)
+ this-base)
+ entries))))
+ (setq ez-dict-entries (reverse entries))
+ (setq ez-dict-separators separators)))
;; Call stack
(defun ez-routine-stack-push (val)
(let ((frame (car ez-call-stack)))
+ (ez-debug-message "\tPushed %x to stack" val)
(setf (elt frame 1) (cons val (elt frame 1)))))
(defun ez-routine-stack-pop ()
(let* ((frame (car ez-call-stack))
(rs-head (car (elt frame 1))))
(setf (elt frame 1) (cdr (elt frame 1)))
+ (ez-debug-message "\tPopped %x from stack" rs-head)
rs-head))
(defun ez-get-local-var (lvar)
- (let ((frame (car ez-call-stack)))
- (aref (elt frame 2) (- lvar 1))))
+ (let* ((frame (car ez-call-stack))
+ (val (aref (elt frame 2) (- lvar 1))))
+ (ez-debug-message "\tRetrieved value %x from local variable %x" val lvar)
+ val))
(defun ez-set-local-var (lvar val)
(let ((frame (car ez-call-stack)))
+ (ez-debug-message "\tSet local variable %x to %x" lvar val)
(aset (elt frame 2) (- lvar 1) val)))
(defun ez-get-pc ()
(defun ez-execute-instr ()
(let ((instr-pc (ez-get-pc))
(opbyte (ez-read-pc-byte-and-inc))
- (optype)
- (opcode nil)
- (operands))
+ (optype) (opcode) (operands))
(cond
((<= #x0 opbyte #x1f)
(setq optype '2op
operand-types '(w)))
((<= #xB0 opbyte #xBF)
(setq optype '0op
- opcode (- opbyte #xb0)))
+ opcode (- opbyte #xb0)
+ operands '()
+ operand-types '()))
((<= #xC0 opbyte #xDF)
- (error "Unsupported op" opbyte))
+ (setq optype '2op
+ opcode (- opbyte #xc0))
+ (let ((operands-and-types (ez-read-var-operands-and-inc)))
+ (setq operands (car operands-and-types)
+ operand-types (cdr operands-and-types))))
((<= #xE0 opbyte #xFF)
(setq optype 'var
opcode (- opbyte #xe0))
operand-types (cdr operands-and-types)))))
(let ((table-row (assoc (list optype opcode) ez-op-table)))
(unless table-row
- (error "Unsupported op" optype opcode))
+ (error "Unsupported op PC:%x Optype:%s Opcode:%x Operands:%s Operand-types:%s"
+ instr-pc optype opcode (ez-list-to-string-hex operands) operand-types))
(let ((mnemonic (elt table-row 1)))
- (message "PC:%x Optype:%s Opcode:%x Mnemonic:%s Operands:%s"
- instr-pc optype opcode mnemonic operands))
+ (ez-debug-message "PC:%x Optype:%s Opcode:%x Mnemonic:%s Operands:%s Operand-types:%s"
+ instr-pc optype opcode mnemonic
+ (ez-list-to-string-hex operands) operand-types))
(funcall (elt table-row 2) operands operand-types))))
(defun ez-read-var-operands-and-inc ()
(let* ((type-byte (ez-read-pc-byte-and-inc))
- (bleh (message (binformat type-byte)))
(types (let ((type1 (lsh type-byte -6)))
(if (= type1 #b11)
nil
(cons type1
- (let ((type2 (lsh (logand #b110000 type-byte) -4)))
+ (let ((type2 (mod (lsh type-byte -4) 4)))
(if (= type2 #b11)
nil
(cons type2
- (let ((type3 (lsh (logand #b1100 type-byte) -2)))
+ (let ((type3 (mod (lsh type-byte -2) 4)))
(if (= type3 #b11)
nil
(cons type3
- (let ((type4 (logand #b11)))
+ (let ((type4 (mod type-byte 4)))
(if (= type4 #b11)
nil
- (list type4)))))))))))))
- (operands nil))
+ (list type4))))))))))))))
(cons
(mapcar
(lambda (type)
(defun ez-do-branch (branch)
(let* ((branch-byte (ez-read-pc-byte-and-inc))
(invert (= 0 (logand branch-byte #b10000000)))
- (single-byte (= 1 (logand branch-byte #b01000000)))
+ (single-byte (> (logand branch-byte #b01000000) 0))
(offset
(if single-byte
(logand branch-byte #b00111111)
(if pos
val
(- val 8192))))))
- (cond
- ((= offset 0)
- (ez-op-rfalse))
- ((= offset 1)
- (ez-op-rtrue))
- (t
- (ez-set-pc (+ (ez-get-pc) offset -2))))))
+ (if (or (and branch (not invert))
+ (and (not branch) invert))
+ (cond
+ ((= offset 0)
+ (ez-op-rfalse))
+ ((= offset 1)
+ (ez-op-rtrue))
+ (t
+ (ez-set-pc (+ (ez-get-pc) offset -2)))))))
;; Operations
'(((0op #x00) rtrue ez-op-rtrue)
((0op #x01) rfalse ez-op-rfalse)
((1op #x00) jz ez-op-jz)
+ ((1op #x05) inc ez-op-inc)
+ ((1op #x06) dec ez-op-dec)
((1op #x0B) ret ez-op-ret)
+ ((0op #x08) ret_pulled ez-op-ret-pulled)
((1op #x0C) jump ez-op-jump)
+ ((2op #x05) inc_jg ez-op-inc-jg)
+ ((2op #x04) dec_jg ez-op-dec-jg)
((2op #x0D) store ez-op-store)
((1op #x0E) load ez-op-load)
((var #x01) storew ez-op-storew)
+ ((2op #x0F) loadw ez-op-loadw)
+ ((var #x02) storeb ez-op-storeb)
+ ((2op #x10) loadb ez-op-loadb)
((2op #x01) je ez-op-je)
+ ((2op #x02) jl ez-op-jl)
+ ((2op #x03) jg ez-op-jg)
+ ((2op #x06) jin ez-op-jin)
+ ((2op #x07) test ez-op-test)
((2op #x08) or ez-op-or)
((2op #x09) and ez-op-and)
((2op #x14) add ez-op-add)
((2op #x16) mul ez-op-mul)
((2op #x17) div ez-op-div)
((2op #x18) mod ez-op-mod)
- ((var #x00) call_fv ez-op-callf)))
+ ((var #x00) call_fv ez-op-callfv)
+ ((1op #x01) get_sibling ez-op-get-sibling)
+ ((1op #x02) get_child ez-op-get-child)
+ ((1op #x03) get_parent ez-op-get-parent)
+ ((2op #x0A) test_attr ez-op-test-attr)
+ ((2op #x0B) set_attr ez-op-set-attr)
+ ((2op #x0C) clear_attr ez-op-clear-attr)
+ ((1op #x09) remove_obj ez-op-remove-obj)
+ ((2op #x0E) insert_obj ez-op-insert-obj)
+ ((var #x03) put_prop ez-op-put-prop)
+ ((2op #x11) get_prop ez-op-get-prop)
+ ((0op #x02) print ez-op-print)
+ ((0op #x0B) new_line ez-op-new-line)
+ ((var #x06) print_num ez-op-print-num)
+ ((var #x05) print_char ez-op-print-char)
+ ((1op #x0A) print_obj ez-op-print-obj)
+ ((var #x04) read ez-op-read)))
(defun ez-op-ret (operands &optional operand-types)
(let ((retval (car operands)))
+ (ez-debug-message "\tReturning value %x" retval)
(ez-pop-call-stack-frame)
(ez-set-var (ez-read-pc-byte-and-inc) retval))
- t)
+ 'run)
+
+(defun ez-op-ret-pulled (operands operand-types)
+ (let ((retval (ez-routine-stack-pop)))
+ (ez-debug-message "\tReturning value %x" retval)
+ (ez-op-ret (list retval)))
+ 'run)
(defun ez-op-rtrue (&optional operands operand-types)
- (ez-op-ret (list 1)))
+ (ez-op-ret (list 1))
+ 'run)
(defun ez-op-rfalse (&optional operands operand-types)
- (ez-op-ret (list 0)))
+ (ez-op-ret (list 0))
+ 'run)
(defun ez-op-jz (operands operand-types)
(ez-do-branch (= (car operands) 0))
- t)
+ 'run)
(defun ez-op-je (operands operand-types)
(ez-do-branch (memq (car operands) (cdr operands)))
- t)
+ 'run)
+
+(defun ez-op-jg (operands operand-types)
+ (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
+ (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
+ (ez-do-branch (> s1 s2)))
+ 'run)
+
+(defun ez-op-jl (operands operand-types)
+ (let ((s1 (ez-decode-signed-operand (car operands) (car operand-types)))
+ (s2 (ez-decode-signed-operand (cadr operands) (cadr operand-types))))
+ (ez-do-branch (< s1 s2)))
+ 'run)
+
+(defun ez-op-inc-jg (operands operand-types)
+ (let ((var (car operands)))
+ (ez-op-inc (list var))
+ (ez-op-jg (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
+ 'run)
+
+(defun ez-op-dec-jl (operands operand-types)
+ (let ((var (car operands)))
+ (ez-op-dec (list var))
+ (ez-op-jl (cons (ez-get-var var) (cdr operands)) (cons 'w (cdr operand-types))))
+ 'run)
+
+(defun ez-op-jin (operands operand-types)
+ (let ((obj (car operands))
+ (n (cadr operands)))
+ (ez-do-branch (or (= n 0)
+ (= n (ez-get-obj-parent obj)))))
+ 'run)
+
+(defun ez-op-test (operands operand-types)
+ (let ((a (car operands))
+ (b (cadr operands)))
+ (ez-do-branch (= (logand a b) b)))
+ 'run)
(defun ez-op-jump (operands operand-types)
(let ((offset (if (eq (car operand-types) 'b)
(ez-decode-signed-byte (car operands))
(ez-decode-signed-word (car operands)))))
(ez-set-pc (+ (ez-get-pc) offset -2)))
- t)
+ 'run)
+
+(defun ez-op-inc (operands &optional operand-types)
+ (let ((var (car operands)))
+ (ez-set-var var (mod (+ 1 (ez-get-var var)) #x10000)))
+ 'run)
+
+(defun ez-op-dec (operands &optional operand-types)
+ (let ((var (car operands)))
+ (ez-set-var var (mod (+ (ez-get-var var) 1) #x10000)))
+ 'run)
(defun ez-op-store (operands operand-types)
(let ((var (car operands))
(a (cadr operands)))
(ez-set-var var a))
- t)
+ 'run)
(defun ez-op-load (operands operand-types)
(let ((var (car operands)))
(ez-set-var (ez-read-pc-byte-and-inc) (ez-get-var var)))
- t)
+ 'run)
(defun ez-op-storew (operands operand-types)
(let ((baddr (car operands))
(n (cadr operands))
(a (caddr operands)))
(ez-mem-set-word (+ baddr (* 2 n)) a))
- t)
+ 'run)
+
+(defun ez-op-loadw (operands operand-types)
+ (let ((baddr (car operands))
+ (n (cadr operands)))
+ (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-word (+ baddr (* 2 n)))))
+ 'run)
+
+(defun ez-op-storeb (operands operand-types)
+ (let ((baddr (car operands))
+ (n (cadr operands))
+ (a (caddr operands)))
+ (ez-mem-set-byte (+ baddr n) a))
+ 'run)
+
+(defun ez-op-loadb (operands operand-types)
+ (let ((baddr (car operands))
+ (n (cadr operands)))
+ (ez-set-var (ez-read-pc-byte-and-inc) (ez-mem-ref-byte (+ baddr n))))
+ 'run)
(defun ez-op-and (operands operand-types)
(let ((a (car operands))
(b (cadr operands)))
(ez-set-var (ez-read-pc-byte-and-inc) (logand a b)))
- t)
+ 'run)
(defun ez-op-or (operands operand-types)
(let ((a (car operands))
(b (cadr operands)))
(ez-set-var (ez-read-pc-byte-and-inc) (logior a b)))
- t)
+ 'run)
(defun ez-op-add (operands operand-types)
(let ((a (car operands))
(b (cadr operands)))
(ez-set-var (ez-read-pc-byte-and-inc) (mod (+ a b) #x10000)))
- t)
+ 'run)
(defun ez-op-sub (operands operand-types)
(let ((a (car operands))
(b (cadr operands)))
(ez-set-var (ez-read-pc-byte-and-inc) (mod (+ (- a b) #x10000) #x10000)))
- t)
+ 'run)
(defun ez-op-mul (a b)
(let ((a (car operands))
(b (cadr operands)))
(ez-set-var (ez-read-pc-byte-and-inc) (mod (* a b) #x10000)))
- t)
+ 'run)
(defun ez-op-div (a b)
(error "Not implemented"))
(defun ez-op-mod (a b)
(error "Not implemented"))
-(defun ez-op-callf (operands operand-types)
+(defun ez-op-callfv (operands operand-types)
(let* ((raddr (car operands))
(call-operands (cdr operands))
(r (* 2 raddr))
(L (ez-mem-ref-byte r))
(n (length call-operands))
(new-pc (+ r 1 (* L 2))))
- (ez-add-call-stack-frame new-pc)
- (dotimes (i L)
- (if (< i n)
- (ez-set-local-var (+ i 1) (elt call-operands i))
- (ez-set-local-var (+ i 1) (ez-mem-ref-word (+ r 1 (* 2 i)))))))
- t)
+ (if (= raddr 0)
+ (ez-set-var (ez-read-pc-byte-and-inc) 0) ; Simply return 0
+ (ez-add-call-stack-frame new-pc)
+ (dotimes (i L)
+ (if (< i n)
+ (ez-set-local-var (+ i 1) (elt call-operands i))
+ (ez-set-local-var (+ i 1) (ez-mem-ref-word (+ r 1 (* 2 i))))))))
+ 'run)
+
+(defun ez-op-test-attr (operands operand-types)
+ (let ((obj (car operands))
+ (attr (cadr operands)))
+ (ez-do-branch (= 1 (ez-get-obj-attr obj attr)))
+ 'run))
+
+(defun ez-op-set-attr (operands operand-types)
+ (let ((obj (car operands))
+ (attr (cadr operands)))
+ (ez-set-obj-attr obj attr 1))
+ 'run)
+
+(defun ez-op-clear-attr (operands operand-types)
+ (let ((obj (car operands))
+ (attr (cadr operands)))
+ (ez-set-obj-attr obj attr 0))
+ 'run)
+
+(defun ez-op-get-sibling (operands operand-types)
+ (let ((sib (ez-get-obj-sibling (car operands))))
+ (ez-set-var (ez-read-pc-byte-and-inc) sib)
+ (ez-do-branch (> sib 0)))
+ 'run)
+
+(defun ez-op-get-child (operands operand-types)
+ (let ((child (ez-get-obj-child (car operands))))
+ (ez-set-var (ez-read-pc-byte-and-inc) child)
+ (ez-do-branch (> child 0)))
+ 'run)
+
+(defun ez-op-get-parent (operands operand-types)
+ (let ((parent (ez-get-obj-parent (car operands))))
+ (ez-set-var (ez-read-pc-byte-and-inc) parent))
+ 'run)
+
+(defun ez-op-remove-obj (operands operand-types)
+ (let ((obj (car operands)))
+ (ez-remove-obj obj))
+ 'run)
+
+(defun ez-op-insert-obj (operands operand-types)
+ (let ((obj1 (car operands))
+ (obj2 (cadr operands)))
+ (ez-insert-obj obj1 obj2))
+ 'run)
+
+(defun ez-op-put-prop (operands operand-types)
+ (let* ((obj (car operands))
+ (prop (cadr operands))
+ (a (caddr operands)))
+ (ez-set-obj-prop obj prop a))
+ 'run)
+
+(defun ez-op-get-prop (operands operand-types)
+ (let* ((obj (car operands))
+ (prop (cadr operands)))
+ (ez-set-var (ez-read-pc-byte-and-inc)
+ (ez-get-obj-prop obj prop)))
+ 'run)
+
+(defun ez-op-print (operands operand-types)
+ (let* ((word-count-and-string (ez-get-zstring-and-length (ez-get-pc)))
+ (word-count (car word-count-and-string))
+ (string (cdr word-count-and-string)))
+ (ez-print string)
+ (ez-increment-pc (* 2 word-count)))
+ 'run)
+
+(defun ez-op-new-line (operands operand-types)
+ (ez-print "\n")
+ 'run)
+
+(defun ez-op-print-num (operands operand-types)
+ (let ((s (ez-decode-signed-operand (car operands) (car operand-types))))
+ (ez-print (number-to-string s)))
+ 'run)
+
+(defun ez-op-print-char (operands operand-types)
+ (let ((c (car operands)))
+ (ez-print (string c)))
+ 'run)
+
+(defun ez-op-print-obj (operands operand-types)
+ (let ((obj (car operands)))
+ (ez-print (ez-get-obj-name obj)))
+ 'run)
+
+(defvar ez--next-read-args nil)
+(defun ez-op-read (operands operand-types)
+ (let ((baddr1 (car operands))
+ (baddr2 (cadr operands)))
+ (setq ez--next-read-args (list baddr1 baddr2)))
+ 'wait-for-input)
+
+(defun ez-op-read2 (input-string)
+ (let* ((baddr1 (car ez--next-read-args))
+ (baddr2 (cadr ez--next-read-args))
+ (dict (ez-get-dictionary))
+ (separators (car dict))
+ (wordlist (cdr dict))
+ (token-start 0))
+
+ (dotimes (i (length input-string))
+ (let ((char (elt input-string i)))
+ (ez-mem-set-byte (+ baddr1 1 i) char)
+ (ez-mem-set-byte (+ baddr1 1 (length input-string)) 0)
+
+ (ez--tokenize baddr1 baddr2)))))
+
+(defun ez--tokenize (taddr baddr)
+
+ (let ((unfinished t)
+ (token-start 0)
+ (token-end 0)
+ (token-string ""))
+ (while unfinished
+ (let ((char (ez-mem-ref-byte (+ taddr 1 token-end))))
+ (cond
+ ((eq char ?\s))
+ ((memq char ez-dict-separators))
+ )
+ ))))
-;; Main
+;; Execution loop
-(defun ez-run (filename)
+(defun ez-load-and-run (filename)
(ez-load-file filename)
(ez-parse-header)
+ (ez-parse-dictionary)
(setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
- (while (ez-execute-inst)))
-
-;; Scratch
-
-(ez-load-file "zork1.z3")
-(ez-parse-header)
-(setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
-(ez-execute-instr)
-
-(binformat #x97)
-"10010111"
-
-
-ez-call-stack
-((28281 nil [33807 0 180 47872 0 0 0 0 0 0 0 0 ...] nil) (22022 nil [33807 65535 0 0 0 0 0 0 0 0 0 0 ...] nil) (20715 nil [0 0 0 0 0 0 0 0 0 0 0 0 ...] nil))
-
-((22049 nil [33807 0 180 47872 0 0 0 0 0 0 0 0 ...] nil) (22022 nil [33807 65535 0 0 0 0 0 0 0 0 0 0 ...] nil) (20715 nil [0 0 0 0 0 0 0 0 0 0 0 0 ...] nil))
-
-
-
-
-
-
-
-
-
-
-
+ (ez-run))
+
+(defvar ez-machine-state nil
+ "Identifies the current executation state of the Z-machine.")
+
+(defun ez-run ()
+ (setq ez-machine-state 'run)
+ (while (eq ez-machine-state 'run)
+ (setq ez-machine-state (ez-execute-instr))))
+
+;;; Buffer and I/O
+;;
+
+(defvar ez-input-marker nil
+ "Marker for input position in buffer.")
+
+(defun ez-setup-buffer ()
+ (with-current-buffer (get-buffer-create "*ez*")
+ (ez-mode)
+ (let ((inhibit-read-only t))
+ (erase-buffer))
+ (setq-local scroll-conservatively 1)
+ (if (markerp ez-input-marker)
+ (set-marker ez-input-marker (point-max))
+ (setq ez-input-marker (point-max-marker)))
+ (goto-char (point-max))))
+
+
+(defun ez-print (string)
+ (with-current-buffer "*ez*"
+ (save-excursion
+ (goto-char ez-input-marker)
+ (insert-before-markers string))))
+
+(defun ez-enter ()
+ (interactive)
+ (if (not (eq ez-machine-state 'wait-for-input))
+ (error "Z-machine not ready for input."))
+ (let ((input-string
+ (downcase
+ (with-current-buffer "*ez*"
+ (buffer-substring ez-input-marker (point-max))))))
+ (delete-region ez-input-marker (point-max))
+ (ez-print (concat input-string "\n"))
+ (ez-debug-message "\tReceived string \"%s\"" input-string)
+ (ez-op-read2 input-string)
+ (ez-run)))
+
+;; Debugging info
+
+(defun ez-setup-debug-buffer ()
+ (with-current-buffer (get-buffer-create "*ez-debug-trace*")
+ (setq-local buffer-read-only t)
+ (let ((inhibit-read-only t))
+ (erase-buffer)
+ (insert "--- Trace Start ---\n\n"))))
+
+(defun ez-debug-message (&rest strings)
+ (with-current-buffer (get-buffer-create "*ez-debug-trace*")
+ (save-excursion
+ (goto-char (point-max))
+ (let ((inhibit-read-only t))
+ (insert (apply #'format-message strings) "\n")))))
+
+(defun ez-debug-memory ()
+ (interactive)
+ (with-current-buffer (get-buffer-create "*ez-debug-memory*")
+ (setq-local buffer-read-only t)
+ (let ((inhibit-read-only t)
+ (old-point (point)))
+ (if (eq major-mode 'hexl-mode)
+ (hexl-mode-exit))
+ (erase-buffer)
+ (insert ez-memory)
+ (setq-local buffer-undo-list nil)
+ (hexl-mode)
+ (goto-char old-point))))
+
+;; Mode
+
+(defvar ez-mode-map
+ (let ((map (make-sparse-keymap)))
+ (define-key map (kbd "RET") 'ez-enter)
+ map))
+
+(define-derived-mode ez-mode text-mode "ez"
+ "Major mode for EZ.")
+
+(when (fboundp 'evil-set-initial-state)
+ (evil-set-initial-state 'ez-mode 'insert))
+
+(defun ez (zfile)
+ (interactive "fEnter name of z3 story file: ")
+ (if (get-buffer "*ez*")
+ (switch-to-buffer "*ez*")
+ (switch-to-buffer "*ez*")
+ (ez-setup-buffer)
+ (ez-load-and-run zfile))
+ "Started EZ.")
+
+(defun ez-debug ()
+ (interactive)
+ (ez-setup-buffer)
+ (ez-setup-debug-buffer)
+ (ez-load-and-run "zork1.z3"))
;;; ez.el ends here