X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=ez.git;a=blobdiff_plain;f=ez.el;h=67e9caf2ad4c1ff7340c4d0e90c92ebcae5b0ac6;hp=b766b70fa89031488c3177f77cc257b13daff697;hb=285e58cc15f4ad51c54bdf482867af2f8c0b5ead;hpb=b524e883ec1b6df18f37738f9f63504e70fa0554

diff --git a/ez.el b/ez.el
index b766b70..67e9caf 100644
--- a/ez.el
+++ b/ez.el
@@ -28,7 +28,27 @@
 
 ;;; Code:
 
-;; Character set tables
+;; 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)
+  (ez-decode-signed-bits b 8))
+
+(defun ez-decode-signed-word (w)
+  (ez-decode-signed-bits w 16))
+
+(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
 
@@ -73,7 +93,8 @@
   "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
 
@@ -85,16 +106,6 @@
 
 ;; 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 ()
@@ -102,6 +113,31 @@
   (dotimes (i 31)
     (aset ez-property-defaults i (aref ez-memory (+ ez-objtab-addr (* 2 i))))))
 
+(defun ez-get-obj-addr (obj-id)
+  (+ ez-objtab-addr (* 2 31) (* 9 (- obj-id 1))))
+
+(defun ez-get-obj-parent (obj-id)
+  (let ((addr (ez-get-obj-addr obj-id)))
+    (ez-mem-ref-byte (+ addr 4))))
+
+(defun ez-get-obj-sibling (obj-id)
+  (let ((addr (ez-get-obj-addr obj-id)))
+    (ez-mem-ref-byte (+ addr 5))))
+
+(defun ez-get-obj-child (obj-id)
+  (let ((addr (ez-get-obj-addr obj-id)))
+    (ez-mem-ref-byte (+ addr 6))))
+
+(defun ez-get-obj-plist-addr (obj-id)
+  (let ((addr (ez-get-obj-addr obj-id)))
+    (ez-mem-ref-word (+ addr 7))))
+
+(defun ez-get-obj-name (obj-id)
+  (let ((plist-addr (ez-get-obj-plist-addr obj-id)))
+    (if (> (ez-mem-ref-byte plist-addr) 0)
+        (ez-get-zstring (+ 1 (ez-get-obj-plist-addr obj-id)))
+      nil)))
+
 (defun ez-get-obj (obj-id)
   (let ((addr (+ ez-objtab-addr
                  (* 2 31)
@@ -115,8 +151,50 @@
      (let ((plist-addr (ez-mem-ref-word (+ addr 7))))
        (if (> (ez-mem-ref-byte plist-addr) 0)
            (ez-get-zstring (+ 1 plist-addr))
-         "")))))
-
+         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 (= prop-addr 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)))))
 
 ;; Z-strings
 
@@ -163,9 +241,9 @@
        ((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))))
@@ -253,7 +331,8 @@
   (ez-get-var (ez-read-pc-byte-and-inc)))
 
 (defun ez-execute-instr ()
-  (let ((opbyte (ez-read-pc-byte-and-inc))
+  (let ((instr-pc (ez-get-pc))
+        (opbyte (ez-read-pc-byte-and-inc))
         (optype)
         (opcode nil)
         (operands))
@@ -262,34 +341,41 @@
       (setq optype '2op
             opcode opbyte
             operands (list (ez-read-pc-byte-and-inc)
-                            (ez-read-pc-byte-and-inc))))
+                           (ez-read-pc-byte-and-inc))
+            operand-types '(b b)))
      ((<= #x20 opbyte #x3F)
       (setq optype '2op
             opcode (- opbyte #x20)
             operands (list (ez-read-pc-byte-and-inc)
-                           (ez-read-pc-var-and-inc))))
+                           (ez-read-pc-var-and-inc))
+            operand-types '(b w)))
      ((<= #x40 opbyte #x5F)
       (setq optype '2op
             opcode (- opbyte #x40)
             operands (list (ez-read-pc-var-and-inc)
-                           (ez-read-pc-byte-and-inc))))
+                           (ez-read-pc-byte-and-inc))
+            operand-types '(w b)))
      ((<= #x60 opbyte #x7F)
       (setq optype '2op
             opcode (- opbyte #x60)
             operands (list (ez-read-pc-var-and-inc)
-                           (ez-read-pc-var-and-inc))))
+                           (ez-read-pc-var-and-inc))
+            operand-types '(w w)))
      ((<= #x80 opbyte #x8F)
       (setq optype '1op
             opcode (- opbyte #x80)
-            operands (list (ez-read-pc-word-and-inc))))
+            operands (list (ez-read-pc-word-and-inc))
+            operand-types '(w)))
      ((<= #x90 opbyte #x9F)
       (setq optype '1op
             opcode (- opbyte #x90)
-            operands (list (ez-read-pc-byte-and-inc))))
+            operands (list (ez-read-pc-byte-and-inc))
+            operand-types '(b)))
      ((<= #xA0 opbyte #xAF)
       (setq optype '1op
             opcode (- opbyte #xa0)
-            operands (list (ez-read-pc-var-and-inc))))
+            operands (list (ez-read-pc-var-and-inc))
+            operand-types '(w)))
      ((<= #xB0 opbyte #xBF)
       (setq optype '0op
             opcode (- opbyte #xb0)))
@@ -297,19 +383,20 @@
       (error "Unsupported op" opbyte))
      ((<= #xE0 opbyte #xFF)
       (setq optype 'var
-            opcode (- opbyte #xe0)
-            operands (ez-read-var-operands-and-inc))))
+            opcode (- opbyte #xe0))
+      (let ((operands-and-types (ez-read-var-operands-and-inc)))
+        (setq operands (car operands-and-types)
+              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" instr-pc optype opcode operands operand-types))
       (let ((mnemonic (elt table-row 1)))
-        (message "Optype:%s Opcode:%x Mnemonic:%s Operands:%s"
-                 optype opcode mnemonic operands))
-      (apply (elt table-row 2) operands))))
+        (message "PC:%x Optype:%s Opcode:%x Mnemonic:%s Operands:%s"
+                 instr-pc optype opcode mnemonic operands))
+      (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
@@ -327,29 +414,185 @@
                                                     nil
                                                   (list type4)))))))))))))
          (operands nil))
-    (mapcar
-     (lambda (type)
-       (cond
-        ((= type 0) (ez-read-pc-word-and-inc))
-        ((= type 1) (ez-read-pc-byte-and-inc))
-        ((= type 2) (ez-read-pc-var-and-inc))))
-     types)))
+    (cons
+     (mapcar
+      (lambda (type)
+        (cond
+         ((= type 0) (ez-read-pc-word-and-inc))
+         ((= type 1) (ez-read-pc-byte-and-inc))
+         ((= type 2) (ez-read-pc-var-and-inc))))
+      types)
+     (mapcar
+      (lambda (type)
+        (if (= type 1)
+            'b
+          'w))
+      types))))
+
+;; Branches
+
+(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)))
+         (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))))))
+    (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
-  '(((var #x0) call_fv ez-op-callf)))
+  '(((0op #x00) rtrue ez-op-rtrue)
+    ((0op #x01) rfalse ez-op-rfalse)
+    ((1op #x00) jz ez-op-jz)
+    ((1op #x0B) ret ez-op-ret)
+    ((1op #x0C) jump ez-op-jump)
+    ((2op #x0D) store ez-op-store)
+    ((1op #x0E) load ez-op-load)
+    ((var #x01) storew ez-op-storew)
+    ((2op #x01) je ez-op-je)
+    ((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)
+    ((1op #x01) get_sibling ez-op-get-sibling)
+    ((1op #x02) get_child ez-op-get-child)
+    ((1op #x03) get_parent ez-op-get-parent)
+    ((var #x03) put_prop ez-op-put-prop)))
+
+(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)))
+
+(defun ez-op-rfalse (&optional operands operand-types)
+  (ez-op-ret (list 0)))
+
+(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-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-callf (raddr &rest operands)
-  (let* ((r (* 2 raddr))
+(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-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)))
+  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)))
+  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)))
+  t)
+
+(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)
+  (let* ((raddr (car operands))
+         (call-operands (cdr operands))
+         (r (* 2 raddr))
          (L (ez-mem-ref-byte r))
-         (n (length operands))
+         (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 operands i))
+          (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)
 
+(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))))
+
+(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))))
+
+(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)
+    (ez-do-branch (> parent 0))))
+
+(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)))
+
 ;; Main
 
 (defun ez-run (filename)
@@ -357,25 +600,15 @@
   (ez-parse-header)
   (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
 
-  (while (ez-execute-inst)))
+  (while (ez-execute-instr)))
 
 ;; 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)
-ez-call-stack
-
-(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))))
-
+;; (ez-load-file "zork1.z3")
+;; (ez-parse-header)
+;; (setq ez-call-stack (list (ez-make-call-stack-frame ez-start-pc)))
+;; (while (ez-execute-instr))
 
+(ez-run "zork1.z3")
 
 ;;; ez.el ends here