;; Utility functions
+(defun ez-decode-signed-bits (n nbits)
+ (if (= 0 (lsh n (- 1 nbits)))
+ n
+ (- n (lsh 1 nbits))))
+
(defun ez-decode-signed-byte (b)
- (lsh b ))
+ (ez-decode-signed-bits b 8))
+
+(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 ""))
+ (let ((d (/ n 2))
+ (new-s (concat (number-to-string (mod n 2)) s)))
+ (if (= d 0)
+ new-s
+ (binformat d new-s))))
;; Memory
(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)
"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))
+ (ez-mem-ref-word (+ (* 2 gvar) ez-globalvartab-addr)))
(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))
;; 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))
-
-(defun ez-get-zstring (base-addr)
- (let ((chars (ez-get-zstring-chars base-addr))
- (cur 0)
- (lock 0)
- (abbrev-char nil)
- (s ""))
+ (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)
+ (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 s (concat s (cdr (ez-get-zstring-and-length abbrev-addr)))))
(setq abbrev-char nil))
((memq char '(1 2 3)) ;Abbreviation
(setq abbrev-char char))
((= char 4)
- (setq cur (mod (+ cur 1) 2)))
+ (setq cur (mod (+ cur 1) 3)))
((= char 5)
- (setq cur (mod (+ 2 (- cur 1)) 2)))
+ (setq cur (mod (+ 3 (- cur 1)) 3)))
(t
(setq s (concat s (substring (elt ez-zstring-alphabets cur)
char (+ char 1))))
(setq cur lock))))
- s))
+ (cons word-count s)))
+
+(defun ez-get-zstring (base-addr)
+ (cdr (ez-get-zstring-and-length base-addr)))
;; Call stack
(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 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))
+ (message "PC:%x Optype:%s Opcode:%x Mnemonic:%s Operands:%s Operand-types:%s"
+ instr-pc optype opcode mnemonic 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
(let ((type4 (logand #b11)))
(if (= type4 #b11)
nil
- (list type4)))))))))))))
- (operands nil))
+ (list type4))))))))))))))
(cons
(mapcar
(lambda (type)
(if (= type 1)
'b
'w))
- types)))))
+ types))))
+
+;; Branches
+
+(defun ez-do-branch (branch)
+ (let* ((branch-byte (ez-read-pc-byte-and-inc))
+ (invert (= 0 (logand branch-byte #b10000000)))
+ (single-byte (> (logand branch-byte #b01000000) 0))
+ (offset
+ (if single-byte
+ (logand branch-byte #b00111111)
+ (let ((pos (= (logand branch-byte #b00100000) 0))
+ (val (+ (* 256 (logand branch-byte #b00011111))
+ (ez-read-pc-byte-and-inc))))
+ (if pos
+ val
+ (- val 8192))))))
+ (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
(defvar ez-op-table
- '(((2op #x14) add ez-op-add)
+ '(((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)
+ ((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 #x06) jin ez-op-jin)
+ ((2op #x08) or ez-op-or)
+ ((2op #x09) and ez-op-and)
+ ((2op #x14) add ez-op-add)
((2op #x15) sub ez-op-sub)
((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-callf)
+ ((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)))
+
+(defun ez-op-ret (operands &optional operand-types)
+ (let ((retval (car operands)))
+ (ez-pop-call-stack-frame)
+ (ez-set-var (ez-read-pc-byte-and-inc) retval))
+ t)
+
+(defun ez-op-rtrue (&optional operands operand-types)
+ (ez-op-ret (list 1))
+ t)
+
+(defun ez-op-rfalse (&optional operands operand-types)
+ (ez-op-ret (list 0))
+ t)
+
+(defun ez-op-jz (operands operand-types)
+ (ez-do-branch (= (car operands) 0))
+ t)
+
+(defun ez-op-je (operands operand-types)
+ (ez-do-branch (memq (car operands) (cdr operands)))
+ t)
+
+(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)))
+ t)
+
+(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)))
+ t)
+
+(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))))
+ t)
+
+(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))))
+ t)
+
+(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)))))
+ t)
+
+(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)
+
+(defun ez-op-inc (operands &optional operand-types)
+ (let ((var (car operands)))
+ (ez-set-var var (mod (+ 1 (ez-get-var var)) #x10000)))
+ t)
+
+(defun ez-op-dec (operands &optional operand-types)
+ (let ((var (car operands)))
+ (ez-set-var var (mod (+ (ez-get-var var) 1) #x10000)))
+ t)
+
+(defun ez-op-store (operands operand-types)
+ (let ((var (car operands))
+ (a (cadr operands)))
+ (ez-set-var var a))
+ t)
+
+(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)
+
+(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)
+
+(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)))))
+ t)
+
+(defun ez-op-storeb (operands operand-types)
+ (let ((baddr (car operands))
+ (n (cadr operands))
+ (a (caddr operands)))
+ (ez-mem-set-byte (+ baddr n) a))
+ t)
+
+(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))))
+ t)
+
+(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)
+
+(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)
(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))))
+ (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ a b) #x10000)))
+ t)
(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))))
+ (ez-set-var (ez-read-pc-byte-and-inc) (mod (+ (- a b) #x10000) #x10000)))
+ t)
(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))))
+ (ez-set-var (ez-read-pc-byte-and-inc) (mod (* a b) #x10000)))
+ t)
-(defun ez-op-div (a b))
+(defun ez-op-div (a b)
+ (error "Not implemented"))
-(defun ez-op-mod (a b))
+(defun ez-op-mod (a b)
+ (error "Not implemented"))
(defun ez-op-callf (operands operand-types)
(let* ((raddr (car operands))
(ez-set-local-var (+ i 1) (ez-mem-ref-word (+ r 1 (* 2 i)))))))
t)
-;; Main
+(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)))
+ t))
-(defun ez-run (filename)
- (ez-load-file filename)
- (ez-parse-header)
- (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
+(defun ez-op-set-attr (operands operand-types)
+ (let ((obj (car operands))
+ (attr (cadr operands)))
+ (ez-set-obj-attr obj attr 1))
+ t)
- (while (ez-execute-inst)))
+(defun ez-op-clear-attr (operands operand-types)
+ (let ((obj (car operands))
+ (attr (cadr operands)))
+ (ez-set-obj-attr obj attr 0))
+ t)
-;; Scratch
+(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)))
+ t)
-(ez-load-file "zork1.z3")
-(ez-parse-header)
-(setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
-(ez-execute-instr)
-ez-call-stack
+(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)))
+ t)
-(defun binformat (n &optional s)
- (unless s
- (setq s ""))
- (let ((d (/ n 2))
- (new-s (concat (number-to-string (mod n 2)) s)))
- (if (= d 0)
- new-s
- (binformat d new-s))))
+(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))
+ t)
+
+(defun ez-op-remove-obj (operands operand-types)
+ (let ((obj (car operands)))
+ (ez-remove-obj obj))
+ t)
+
+(defun ez-op-insert-obj (operands operand-types)
+ (let ((obj1 (car operands))
+ (obj2 (cadr operands)))
+ (ez-insert-obj obj1 obj2))
+ t)
+
+(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))
+ t)
+
+(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)))
+ t)
+
+(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)))
+ t)
+
+(defun ez-op-new-line (operands operand-types)
+ (ez-print "\n")
+ t)
+
+(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)))
+ t)
+
+(defun ez-op-print-char (operands operand-types)
+ (let ((c (car operands)))
+ (ez-print (string c)))
+ t)
+(defun ez-op-print-obj (operands operand-types)
+ (let ((obj (car operands)))
+ (ez-print (ez-get-obj-name obj)))
+ t)
+
+;; Execution loop
+
+(defun ez-run (filename)
+ (ez-load-file filename)
+ (ez-parse-header)
+ (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
+ (while (ez-execute-instr)))
+
+
+;;; Buffer and I/O
+;;
+
+(defun ez-render-prompt ()
+ (with-current-buffer "*ez*"
+ (let ((update-point (= ez-input-marker (point)))
+ (update-window-points (mapcar (lambda (w)
+ (list (= (window-point w) ez-input-marker)
+ w))
+ (get-buffer-window-list nil nil t))))
+ (save-excursion
+ (set-marker-insertion-type ez-prompt-marker nil)
+ (set-marker-insertion-type ez-input-marker t)
+ (let ((inhibit-read-only t))
+ (delete-region ez-prompt-marker ez-input-marker)
+ (goto-char ez-prompt-marker)
+ (insert
+ ">"
+ (propertize " " ; Need this to be separate to mark it as rear-nonsticky
+ 'read-only t
+ 'rear-nonsticky t)))
+ (set-marker-insertion-type ez-input-marker nil))
+ (goto-char ez-input-marker))))
+
+(defvar ez-prompt-marker nil
+ "Marker for prompt position in buffer.")
+
+(defvar ez-input-marker nil
+ "Marker for prompt position in buffer.")
+
+(defun ez-setup-buffer ()
+ (with-current-buffer (get-buffer-create "*ez*")
+ (let ((inhibit-read-only t))
+ (delete-region (point-min) (point-max)))
+ (setq-local scroll-conservatively 1)
+ (if (markerp ez-prompt-marker)
+ (set-marker ez-prompt-marker (point-max))
+ (setq ez-prompt-marker (point-max-marker)))
+ (if (markerp ez-input-marker)
+ (set-marker ez-input-marker (point-max))
+ (setq ez-input-marker (point-max-marker)))
+ (goto-char (point-max))
+ (ez-render-prompt)))
+
+
+(defun ez-print (string)
+ (with-current-buffer "*ez*"
+ (save-excursion
+ (goto-char ez-prompt-marker)
+ (insert-before-markers string))))
+
+;; 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-mode)
+ (ez-setup-buffer)
+ (ez-run zfile))
+ "Started EZ.")
+
+(defun ez-debug ()
+ (interactive)
+ (switch-to-buffer "*ez*")
+ (ez-mode)
+ (ez-setup-buffer)
+ (ez-run "zork1.z3"))
;;; ez.el ends here