feat: add pigibrack macro expansion tool

playground/macros.scm

@@ -0,0 +1,16 @@
+(define-module (playground macros)
+  #:export (inc unless* demo))
+
+(define-syntax-rule (inc x)
+  (+ x 1))
+
+(define-syntax unless*
+  (syntax-rules ()
+    ((_ test body ...)
+     (if (not test)
+         (begin body ...)))))
+
+(define (demo x)
+  (unless* (> x 0)
+    (display "non-positive"))
+  (inc x))