Introduce optional-args

src/swark/core.cljc

@@ -1,5 +1,6 @@
 (ns swark.core
-  (:require [clojure.string :as str]))
+  (:require [clojure.string :as str]
+            [clojure.set :as set]))
 
 ;; SWiss ARmy Knife - Your everyday clojure toolbelt!
 ;; Copyright 2024 - Stan Verberkt ([email protected])
@@ -71,6 +72,20 @@
          predicate (if ns #{ns} nil?)]
      (filter-keys map (comp predicate namespace)))))
 
+;; TODO: Add tests
+(defn optional-args
+  "Returns a function that selects and renames keys, and adds defaults for sequentialargs (as destructured by &). Supply a props map containing permitted input keys as keys, and a map with :default & :rename as val.
+`((optional-args {:name {:rename :person/name :default "Unnamed person"} :from {:rename :person/from :default "Nowhere"}}) {:name "Me"}) => #:person{:name "Me" :from "Nowhere"}`"
+  [props]
+  (let [renames (map-vals :rename props)
+        defaults (map-vals :default props)]
+    (fn optional-args* [args]
+      (let [m (apply hash-map args)]
+        (as-> m m'
+          (select-keys m' (keys props))
+          (merge defaults m')
+          (set/rename-keys m' renames))))))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Try and catch