From ea7e56385cc13c7a6f672875d8c693ee09ca1dc7 Mon Sep 17 00:00:00 2001
From: Edward Langley <el-github@elangley.org>
Date: Sat, 15 Jul 2023 10:11:11 -0700
Subject: [PATCH] feat: add of-type to generate semipredicates

---
 lens.lisp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lens.lisp b/lens.lisp
index d9263ae..21fca6e 100644
--- a/lens.lisp
+++ b/lens.lisp
@@ -193,6 +193,11 @@
         (alexandria:ends-with-subseq suffix
                                      it))))
 
+(defun of-type (type)
+  (lambda (it)
+    (when (typep it type)
+      it)))
+
 (defun transform-head (fun)
   (lambda (it)
     (typecase it