Drafted programme installation procedures.

diff --git a/mars.scm b/mars.scm
index f2e3d99..d7a0de2 100644 (file)
--- a/mars.scm
+++ b/mars.scm
@@ -4,6 +4,7 @@
 
 (import (chicken io)
         (chicken string)
+        (chicken random)
         matchable)
 
 ;;; Constants
@@ -13,44 +14,115 @@
 (define max-steps 10000)
 
 
-;;; Memory setup
+;;; Instructions
+;;
+
+(define ((blah x y) . args)
+  (match args
+    (('x q) (+ x q) q)
+    (('y q) y)))
+
+(define ((make-instr opcode modifier A-mode A-num B-mode B-num name) . args)
+  (match args
+    (('copy n) (make-instr opcode modifier A-mode A-num B-mode B-num n))
+    (('opcode) opcode)
+    (('modifier) modifier)
+    (('A-mode) A-mode)
+    (('A-num) A-num)
+    (('B-mode) B-mode)
+    (('B-num) B-num)
+    (('name) name)
+    (('print) (print opcode
+                     (if (null? modifier) "" (concat "." modifier))
+                     " " (mode-string A-mode) A-num
+                     ", " (mode-string B-mode) B-num
+                     (if (null? name) "" (concat " ; " name))))
+    (('set-opcode! x n) (set! opcode x) (set! name n))
+    (('set-modifier! x n) (set! modifier x) (set! name n))
+    (('set-A-mode! x n) (set! A-mode x) (set! name n))
+    (('set-A-num! x n) (set! A-num x) (set! name n))
+    (('set-B-mode! x n) (set! B-mode x) (set! name n))
+    (('set-B-num! x n) (set! B-num x) (set! name n))))
+
+(define (mode-string mode)
+   (case mode
+     ((immediate) "#")
+     ((direct) "")
+     ((indirect-A "*"))
+     ((indirect-B "@"))
+     ((pre-indirect-A "{"))
+     ((pre-indirect-B "<"))
+     ((post-indirect-A "}"))
+     ((post-indirect-B ">"))))
+
+(define initial-instruction
+  (make-instr 'DAT '() 'immediate 0 'immediate 0 '()))
+
+;;; Memory setup and addressing
 ;;
 
 (define core (make-vector core-size '()))
+
+(define (initialize-core)
+  (let loop ((i 0))
+    (unless (< i core-size)
+      (vector-set! core i (initial-instruction 'copy '()))
+      (loop (+ i 1)))))
+
 (define (addr+ . args)
   (foldl (lambda (a b)
            (modulo (+ a b core-size) core-size))
          0 args))
 
-;;; Instructions
+;;; Programmes
 ;;
 
-(define (make-instr opcode modifier A-mode A-num B-mode B-num))
-(define (instr-opcode instr) (list-ref instr 0))
-(define (instr-modifier instr) (list-ref instr 1))
-(define (instr-A-mode instr) (list-ref instr 2))
-(define (instr-A-num instr) (list-ref instr 3))
-(define (instr-B-mode instr) (list-ref instr 4))
-(define (instr-B-num instr) (list-ref instr 5))
-
-
-;;; Players
-;;
-
-(define (make-player name . ptrs)
-  (cons name ptrs))
-
-(define (player-ptrs player)
-  (cdr player))
-
-(define (player-name player)
-  (car player))
+(define (make-prog name instrs offset)
+  (list name instructions offset))
+
+(define (prog-name prog) (list-ref prog 0))
+(define (prog-instrs prog) (list-ref prog 1))
+(define (prog-offset prog) (list-ref prog 2))
+
+(define (install-prog prog addr)
+  (let loop ((ptr addr)
+             (instrs (prog-instrs prog)))
+    (unless (null? instrs)
+      (vector-set! core ptr (instr-copy (car instrs)))
+      (loop (addr+ ptr 1) (cdr instrs))))
+  (make-player (prog-name prog)
+               (addr+ addr (prog-offset prog))))
+
+(define (can-install-prog? prog-len addr)
+  (let loop ((ptr addr)
+             (remaining prog-len))
+    (if (= remaining 0)
+        #t
+        (if ((vector-ref core ptr) 'name)
+            #f
+            (loop (addr+ ptr 1)
+                  (- remaining 1))))))
+
+(define (install-progs progs)
+  (let loop ((players '())
+             (progs-left progs))
+    (if (null? progs-left)
+        players
+        (let ((addr (pseudo-random-integer core-size))
+              (prog (car progs-left)))
+          (if (can-install-prog? (length (prog-instrs prog)) addr)
+              (loop (cons (install-prog prog addr) players)
+                    (cdr progs-left))
+              (loop players progs-left))))))
+
+(define (make-player name ptr)
+  (list name ptr))
 
 (define (player-set-ptrs! player ptrs)
-  (set-cdr! player ptrs))
+  (set-cdr! prog-queue ptrs))
 
 
-;;; Main loop
+;;; Executive function
 ;;
 
 (define (run players step)
@@ -91,30 +163,31 @@
       ((NOP))
       (else
        (error "Unrecognised opcode" (instr-opcode instr))))))
-               
+
 (define (eval-operand mode num ptr)
-  (case mode
-    ((immediate) 0)
-    ((direct) num)
-    ((indirect-A) (addr+ num (instr-A-num (vector-ref core (addr+ ptr num)))))
-    ((indirect-B) (addr+ num (instr-B-num (vector-ref core (addr+ ptr num)))))
-    ((pre-indirect-A)
-     (let ((aux-instr (vector-ref core (addr+ ptr num))))
-       (instr-set-A-num! aux-instr (addr+ -1 (instr-A-num aux-instr)))
-       (addr+ num (instr-A-num aux-instr))))
-    ((pre-indirect-B)
-     (let ((aux-instr (vector-ref core (addr+ ptr num))))
-       (instr-set-B-num! aux-instr (addr+ -1 (instr-B-num aux-instr)))
-       (addr+ num (instr-B-num aux-instr))))
-    ((post-indirect-A)
-     (let* ((aux-instr (vector-ref core (addr+ ptr num)))
-            (old-A-num (instr-A-num aux-instr)))
-       (instr-set-A-num! aux-instr (addr+ 1 (instr-A-num aux-instr)))
-       (addr+ num old-A-num)))
-    ((post-indirect-B)
-     (let* ((aux-instr (vector-ref core (addr+ ptr num)))
-            (old-B-num (instr-B-num aux-instr)))
-       (instr-set-B-num! aux-instr (addr+ 1 (instr-B-num aux-instr)))
-       (addr+ num old-B-num)))
-    (else
-     (error "Unrecognized mode" mode))))
+  (addr+ ptr
+         (case mode
+           ((immediate) 0)
+           ((direct) num)
+           ((indirect-A) (addr+ num (instr-A-num (vector-ref core (addr+ ptr num)))))
+           ((indirect-B) (addr+ num (instr-B-num (vector-ref core (addr+ ptr num)))))
+           ((pre-indirect-A)
+            (let ((aux-instr (vector-ref core (addr+ ptr num))))
+              (instr-set-A-num! aux-instr (addr+ -1 (instr-A-num aux-instr)))
+              (addr+ num (instr-A-num aux-instr))))
+           ((pre-indirect-B)
+            (let ((aux-instr (vector-ref core (addr+ ptr num))))
+              (instr-set-B-num! aux-instr (addr+ -1 (instr-B-num aux-instr)))
+              (addr+ num (instr-B-num aux-instr))))
+           ((post-indirect-A)
+            (let* ((aux-instr (vector-ref core (addr+ ptr num)))
+                   (old-A-num (instr-A-num aux-instr)))
+              (instr-set-A-num! aux-instr (addr+ 1 (instr-A-num aux-instr)))
+              (addr+ num old-A-num)))
+           ((post-indirect-B)
+            (let* ((aux-instr (vector-ref core (addr+ ptr num)))
+                   (old-B-num (instr-B-num aux-instr)))
+              (instr-set-B-num! aux-instr (addr+ 1 (instr-B-num aux-instr)))
+              (addr+ num old-B-num)))
+           (else
+            (error "Unrecognized mode" mode)))))