From a59bfd4f9a8cae335025aa8acd509d41fe9a398b Mon Sep 17 00:00:00 2001
From: Arun Isaac
Date: Mon, 20 Apr 2026 00:23:21 +0100
Subject: Add add lens.

---
 kaagum/lens.scm | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kaagum/lens.scm b/kaagum/lens.scm
index 6739244..bbd11f5 100644
--- a/kaagum/lens.scm
+++ b/kaagum/lens.scm
@@ -24,6 +24,7 @@
   #:export (vector-nth
             in-json
             push
+            add
             prepend-over
             alist-delete-over))
 
@@ -51,6 +52,10 @@ possible to traverse JSON trees."
 on."
   (over lens (cut cons x <>) object))
 
+(define (add lens x object)
+  "Add @var{x} onto the part of @var{object} that @var{lens} focuses on."
+  (over lens (cut + x <>) object))
+
 (define (prepend-over lens lst object)
   "Prepend @var{lst} to the part of @var{object} that @var{lens} focuses
 on."
-- 
cgit 1.4.1