feat: curried equality

data-lens.asd

@@ -1,5 +1,8 @@
 (asdf:defsystem #:data-lens
-  :description "Utilities for building data transormations from composable functions, modeled on lenses and transducers"
+  :description #.(format nil "~a ~a ~a"
+                         "Utilities for building data transormations from"
+                         "composable functions, modeled on lenses and"
+                         "transducers")
   :author "Edward Langley <el-cl@elangley.org>"
   :license "MIT"
   :depends-on (:cl-ppcre

lens.lisp

@@ -234,8 +234,9 @@ contain the new value at the location focused by the lens."
            #:compress-runs #:combine-matching-lists #:sorted #:applicable-when
            #:of-length #:of-min-length #:of-max-length #:transform-head
            #:maximizing #:zipping #:applying #:splice-elt #:transform-elt #:denest
-           #:op #:defalias #:<> #:<>1
-           #:•))
+           #:op #:defalias #:<> #:<>1 #:== #:•
+           ))
+             
 (in-package :data-lens)
 
 
@@ -275,6 +276,10 @@ contain the new value at the location focused by the lens."
                when (equal key a-key) do
                  (return (car value)))))))
 
+(defun-ct == (target &key (test 'eql))
+  (lambda (v)
+    (funcall test target v)))
+
 (defun-ct deduplicate (&optional (test 'eql))
   (lambda (it)
     (remove-duplicates it :test test)))