some cleanup, fix sequences

bytecode-compiler.scm

@@ -1,7 +1,6 @@
 (use-modules (ice-9 match)
              (ice-9 format)
              (srfi srfi-1)
-             (srfi srfi-2)
              (srfi srfi-9)
              (oop goops)
              ((rnrs base) #:version (6) #:select (assert)))
@@ -17,12 +16,6 @@
 
 (define atom? (negate pair?))
 
-(define finish-pc 0)
-
-(define (conjoin . preds)
-  (lambda (x)
-    (any (lambda (pred) (pred x)) preds)))
-
  ;; Activation frames
 (define-class <frame> ()
   (next #:init-value #f #:accessor frame-next)
@@ -32,7 +25,8 @@
   (format out "#<<frame> (next=~s) (args=~s)>" (frame-next f) (frame-values f)))
 
 (define (frame? x)
-  (is-a? x <frame>))
+  (or (eq? #f x)
+      (is-a? x <frame>)))
 
 (define (allocate-frame size+1)
   (make <frame> #:values (make-vector size+1)))
@@ -84,29 +78,24 @@
 
  ;; Virtual machine registers and functions
 (define-syntax define-registers
-  (syntax-rules (null false)
-    [(_ name null more ...)
-     (begin (define name (make-parameter '()))
-            (define-registers more ...))]
-    [(_ name false more ...)
-     (begin (define name (make-parameter #f))
+  (syntax-rules ()
+    [(_ name default more ...)
+     (begin (define name (make-parameter default))
             (define-registers more ...))]
     [(_) '()]))
 
 (define-registers
-  *globals*    null
-  *primitives* null
-  *stack*      null
-  *constants*  null
-  *code*       null
-  *env*        false
-  *val*        false
-  *pc*         false
-  *finish-pc*  false
-  *fun*        false
-  *arg1*       false
-  *arg2*       false
-  *exit*       false)
+  *globals*    '()
+  *primitives* '()
+  *stack*      '()
+  *constants*  '()
+  *code*       '()
+  *env*        #f
+  *val*        #f
+  *pc*         #f
+  *finish-pc*  #f
+  *fun*        #f
+  *exit*       #f)
 
 (define (stack-push v)
   (*stack* (cons v (*stack*))))
@@ -150,7 +139,7 @@
   (pair? pair? 1)
   (symbol? symbol? 1)
   (eq? eq? 2)
-  ;; These are not direct instructions, but we act like they are? I'm a little confused
+  ;; These are not direct instructions, they can be invoked by an argument
   (+ + 2)
   (- - 2)
   (* * 2)
@@ -176,7 +165,7 @@
   (if (null? (cdr e*))
       (meaning (car e*) r tail?)
       (+sequence+ (meaning (car e*) r #f)
-                  (meaning-sequence (car e*) r tail?))))
+                  (meaning-sequence (cdr e*) r tail?))))
 
 (define (meaning-alternative e1 e2 e3 r tail?)
   (+alternative+ (meaning e1 r #f)
@@ -505,12 +494,12 @@
   (stack-push (*val*)))
 
 (define-inst (preserve-env 37)
-  (assert ((conjoin frame? boolean?) (*env*)))
+  (assert (frame? (*env*)))
   (stack-push (*env*)))
 
 (define-inst (restore-env 38)
   (*env* (stack-pop))
-  (assert ((conjoin frame? boolean?) (*env*))))
+  (assert (frame? (*env*))))
 
 (define-inst (pop-function 39)
   (*fun* (stack-pop)))