Temporary test file

macro-test.scm

@@ -0,0 +1,77 @@
+;; A temporary testbed file
+(import (scheme base)
+        (scheme eval)
+        ;(scheme file)
+        ;(scheme read)
+        (scheme write)
+        (scheme cyclone common)
+        (scheme cyclone util)
+        ;(scheme cyclone cgen)
+        (scheme cyclone transforms)
+        (scheme cyclone macros)
+        ;(scheme cyclone libraries)
+        )
+
+(define input-program '(lambda (x) (begin (+ x x) 1 2 3)))
+
+      ;; Load macros for expansion phase
+      (let ((macros (filter 
+                      (lambda (v) 
+                        (macro? (Cyc-get-cvar (cdr v))))
+                      (Cyc-global-vars))))
+        (set! *defined-macros*
+              (append
+                macros
+                *defined-macros*)))
+      (macro:load-env! *defined-macros* (create-environment '() '()))
+
+      ;; Expand macros
+      (set! input-program (my-expand input-program (macro:get-env)))
+      (write "---------------- after macro expansion:")
+      (write input-program) ;pretty-print
+
+(define (my-expand exp env)
+  (cond
+    ((const? exp)      exp)
+    ((prim? exp)       exp)
+    ((ref? exp)        exp)
+    ((quote? exp)      exp)
+;; TODO: need a way of taking a begin here and splicing its contents
+;; into the body
+    ((lambda? exp)     `(lambda ,(lambda->formals exp)
+                          ,@(map 
+                            ;; TODO: use extend env here?
+                            (lambda (expr) (my-expand expr env))
+                            (lambda->exp exp))))
+    ((define? exp)     (if (define-lambda? exp)
+                           (my-expand (define->lambda exp) env)
+                          `(define ,(my-expand (define->var exp) env)
+                                ,@(my-expand (define->exp exp) env))))
+    ((set!? exp)       `(set! ,(my-expand (set!->var exp) env)
+                              ,(my-expand (set!->exp exp) env)))
+    ((if? exp)         `(if ,(my-expand (if->condition exp) env)
+                            ,(my-expand (if->then exp) env)
+                            ,(if (if-else? exp)
+                                 (my-expand (if->else exp) env)
+                                 ;; Insert default value for missing else clause
+                                 ;; FUTURE: append the empty (unprinted) value
+                                 ;; instead of #f
+                                 #f)))
+    ((app? exp)
+     (cond
+     ((symbol? (car exp))
+      (let ((val (env:lookup (car exp) env #f)))
+        (if (tagged-list? 'macro val)
+          (my-expand ; Could expand into another macro
+            (macro:expand exp val env)
+            env)
+          (map
+            (lambda (expr) (my-expand expr env))
+            exp))))
+
+     (else
+       (map 
+        (lambda (expr) (my-expand expr env))
+        exp))))
+    (else
+      (error "unknown exp: " exp))))