X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=jars.git;a=blobdiff_plain;f=mars.scm;h=2f4db9de8672d3b44b66020ad03437e68253f1d5;hp=57e3e13e3f77809ca51d491c4682e1b5afcc0282;hb=d77eebde986b6bd5e5c25c40523920dfcac96f13;hpb=c30656b58f082be264e382d0da5866c4c04a10f7

diff --git a/mars.scm b/mars.scm
index 57e3e13..2f4db9d 100644
--- a/mars.scm
+++ b/mars.scm
@@ -2,6 +2,10 @@
 ;;; An implementation of the Memory Array Redcode Simulator (MARS)
 ;;;
 
+(import (chicken io)
+        (chicken string)
+        matchable)
+
 ;;; Constants
 ;;
 
@@ -18,7 +22,13 @@
 ;;; Instructions
 ;;
 
-(define (make-instr opcode modifier addrA modeA addrB modeB))
+(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
@@ -40,24 +50,51 @@
 ;;; Main loop
 ;;
 
-(define (list-rot l)
-  (if (> (length l) 1)
-      (append (cdr l) (list (car l)))
-      l))
-
-(define (run playerA playerB step)
+(define (run players step)
   (cond
-   ((> step max-steps) 'tie)
-   ((null? (player-ptrs playerA) playerB))
-   ((null? (player-ptrs playerB) playerA))
+   ((> step max-steps) players)      ;Tie between remaining players
+   ((<= (length players) 1) players) ;There's only one player left who thus wins
    (else
-    (let ((ptrs (player-ptrs playerA)))
-      (player-set-ptrs! (append (cdr ptrs)
-                                (execute-instr (car ptrs)))))
-    (run playerB player A (+ step 1)))))
+    (let ((player (car players))
+          (other-players (cdr players))
+          (ptrs (player-ptrs player)))
+      (let ((new-ptrs (execute-instr (car ptrs))))
+        (if (null? new-ptrs)
+            (run other-players (+ step 1))
+            (begin
+              (player-set-ptrs! (append (cdr ptrs) new-ptrs))
+              (run (append other-players (list player)) (+ step 1)))))))))
 
 (define (execute-instr ptr)
-  (let ((instr (vector-ref core ptr)))
-    (match instr
-      ())))
+  (let* ((instr (vector-ref core ptr))
+         (A-operand (eval-operand (instr-A-mode instr) (instr-A-num) ptr))
+         (B-operand (eval-operand (instr-B-mode instr) (instr-B-num) ptr)))
+    (case (instr-opcode instr)
+      ((DAT))
+      ((MOV))
+      ((ADD))
+      ((SUB))
+      ((MUL))
+      ((DIV))
+      ((MOD))
+      ((JMP))
+      ((JMN))
+      ((DJN))
+      ((SEQ CMP))
+      ((SNE))
+      ((SLT))
+      ((SPL))
+      ((NOP))
+      (else
+       (error "Unrecognised opcode" (instr-opcode instr))))))
                
+(define (eval-operand mode num ptr)
+  (case mode
+    ((immediate))
+    ((direct))
+    ((indirect-A))
+    ((indirect-B))
+    ((pre-indirect-A))
+    ((pre-indirect-B))
+    ((post-indirect-A))
+    ((post-indirect-B))))