fork vars

Author: borkdude

src/sci/core.cljc

@@ -269,8 +269,23 @@
   "Forks a context (as produced with `init`) into a new context. Any new
   vars created in the new context won't be visible in the original
   context."
-  [ctx]
-  (update ctx :env (fn [env] (atom @env))))
+  ([ctx]
+   (update ctx :env (fn [env] (atom @env))))
+  ([ctx {:keys [clone-vars]}]
+   (update ctx :env (fn [env]
+                      (let [env @env
+                            env (if clone-vars
+                                  (update env :namespaces
+                                          (fn [namespaces]
+                                            (update-vals namespaces (fn [namespace]
+                                                                      (update-vals namespace
+                                                                                   (fn [var]
+                                                                                     (if (utils/var? var)
+                                                                                       (.clone ^sci.lang.Var var)
+                                                                                       var)))))))
+
+                                  env)]
+                        (atom env))))))
 
 (defn eval-string*
   "Evaluates string `s` in the context of `ctx` (as produced with

src/sci/lang.cljc

@@ -249,7 +249,10 @@
     (apply @this a b c d e f g h i j k l m n o p q r s t rest))
   #?(:clj
      (applyTo [this args]
-              (apply @this args))))
+              (apply @this args)))
+  #?@(:clj [Cloneable
+            (clone [_this]
+                   (new Var root sym meta thread-bound needs-ctx watches))]))
 
 #?(:clj
    ;; Use public interface for print-method so it can be overriden in bb itself