Add a first implementation of a macro expander.

This half-finished macro expander is the most satisfying piece of code I
have ever written.

1 files changed, 25 insertions, 0 deletions

diff --git a/gensym.csc b/gensym.csc
new file mode 100644
index 0000000..a7c30c5
--- /dev/null
+++ b/gensym.csc
@@ -0,0 +1,25 @@
+(define-library (csc gensym)
+  (export
+    gensym
+    gensym=?)
+  (import (scheme base))
+  (begin
+
+
+    (define-record-type <gensym>
+      (make-gensym id)
+      gensym?
+      (id gensym-id))
+
+
+    (define (gensym=? s1 s2)
+      (= (gensym-id s1) (gensym-id s2)))
+
+
+    (define *next-id* 0)
+
+
+    (define (gensym)
+      (let ((sym (make-gensym *next-id*)))
+        (set! *next-id* (+ 1 *next-id*))
+        sym))))