add support for nested lambdas

example/lambdas.sex

@@ -28,4 +28,11 @@
                                             (return (+ a b 100)))
                                           a b))
 
+  (var (fn int ((int))) l-1
+       (lambda int ((int a)) ()
+         (var (fn int ((int))) l-2
+              (lambda int ((int a)) ()
+                (return (+ 60 a))))
+         (return (+ 600 (l-2 a)))))
+  (printf "Calling nested lambdas: %d\n" (l-1 6))
   (return 0))

semen.scm

@@ -134,8 +134,8 @@
       (let ((lambda-name (semen-make-lambda-name (hash-table-ref env :fn-name)
                                                  (hash-table-ref env :lambda-counter))))
         (set! (hash-table-ref env :lambda-aux-code)
-          (cons (semen-make-aux-lambda-struct lambda-name form)
-                (hash-table-ref env :lambda-aux-code)))
+          (append (semen-make-aux-lambda-struct lambda-name form)
+                  (hash-table-ref env :lambda-aux-code)))
         (set! (hash-table-ref env :lambda-counter)
           (+ (hash-table-ref env :lambda-counter) 1))
         lambda-name)
@@ -150,7 +150,7 @@
     (('lambda ret-type arglist captures . body)
      ;; Captures are ignored for now, but
      ;; we'll need them for TODO: closures support
-     `(fn ,ret-type ,name ,arglist ,@body))
+     (process-fn `(fn ,ret-type ,name ,arglist ,@body) (list)))
     (else (assert #f (fmt #f "Malformed lambda " form)))))
 
 ;;; Struct