All is one-op instructions (save push). Code in memory (this will allow compilation)

scmvm/assembler.scm

@@ -13,21 +13,22 @@
       inst-obj
       (error (format #f "could not find instruction ~a" inst))))
 
-(define (instruction-size inst)
-  (case (instruction-type (lookup-instruction inst))
-    [(i j) 5]
-    [(o)   1]))
-
-(define instruction? pair?)
-(define label? (compose not instruction?))
+(define label? (compose not pair?))
+(define (variable? x)
+  (and (pair? x) (eq? (car x) 'variable)))
+(define (instruction? x)
+  (and (not (label? x))
+       (not (variable? x))))
 
 (define (find-labels inst-seq n)
   (cond
    [(null? inst-seq) '()]
    [(label? (car inst-seq))
     (acons (car inst-seq) n (find-labels (cdr inst-seq) n))]
+   [(variable? (car inst-seq))
+    (acons (cadar inst-seq) n (find-labels (cdr inst-seq) (+ n 4)))]
    [else
-    (find-labels (cdr inst-seq) (+ n (instruction-size (caar inst-seq))))]))
+    (find-labels (cdr inst-seq) (if (eq? (caar inst-seq) 'push) (+ n 5) (+ n 1)))]))
 
 (define (write-word word)
   (define bv (make-bytevector 4))
@@ -37,16 +38,20 @@
 (define (assemble inst-seq port)
   (with-output-to-port port
     (lambda ()
-      (define labels (find-labels inst-seq 0))
+      (define labels (find-labels inst-seq 1))
       (let loop ([seq inst-seq])
         (cond
          [(null? seq) '()]
          [(label? (car seq)) (loop (cdr seq))]
+         [(variable? (car seq))
+          (write-word (caddar seq))
+          (loop (cdr seq))]
          [else
           (let* [(inst (car seq))
                  (inst-obj (lookup-instruction (car inst)))]
             (write-u8 (instruction-code inst-obj))
-            (case (instruction-type inst-obj)
-              [(i) (write-word (cadr inst))]
-              [(j) (write-word (assq-ref labels (cadr inst)))])
+            (when (eq? (car inst) 'push)
+              (if (number? (cadr inst))
+                  (write-word (cadr inst))
+                  (write-word (assq-ref labels (cadr inst)))))
             (loop (cdr seq)))])))))