no tail

cjs/index.js

@@ -7,6 +7,7 @@ const {keys} = Object;
 const Primitive = String;   // it could be Number
 const primitive = 'string'; // it could be 'number'
 
+const ignore = {};
 const object = 'object';
 
 const noop = (_, value) => value;
@@ -20,19 +21,26 @@ const Primitives = (_, value) => (
 );
 
 const revive = (input, parsed, output, $) => {
+  const lazy = [];
   for (let ke = keys(output), {length} = ke, y = 0; y < length; y++) {
-    const key = ke[y];
-    const value = output[key];
+    const k = ke[y];
+    const value = output[k];
     if (value instanceof Primitive) {
       const tmp = input[value];
       if (typeof tmp === object && !parsed.has(tmp)) {
         parsed.add(tmp);
-        output[key] = $.call(output, key, revive(input, parsed, tmp, $));
-      } else {
-        output[key] = $.call(output, key, tmp);
+        output[k] = ignore;
+        lazy.push({k, a: [input, parsed, tmp, $]});
       }
-    } else
-      output[key] = $.call(output, key, value);
+      else
+        output[k] = $.call(output, k, tmp);
+    }
+    else if (output[k] !== ignore)
+      output[k] = $.call(output, k, value);
+  }
+  for (let {length} = lazy, i = 0; i < length; i++) {
+    const {k, a} = lazy[i];
+    output[k] = $.call(output, k, revive.apply(null, a));
   }
   return output;
 };

esm/index.js

@@ -6,6 +6,7 @@ const {keys} = Object;
 const Primitive = String;   // it could be Number
 const primitive = 'string'; // it could be 'number'
 
+const ignore = {};
 const object = 'object';
 
 const noop = (_, value) => value;
@@ -19,19 +20,26 @@ const Primitives = (_, value) => (
 );
 
 const revive = (input, parsed, output, $) => {
+  const lazy = [];
   for (let ke = keys(output), {length} = ke, y = 0; y < length; y++) {
-    const key = ke[y];
-    const value = output[key];
+    const k = ke[y];
+    const value = output[k];
     if (value instanceof Primitive) {
       const tmp = input[value];
       if (typeof tmp === object && !parsed.has(tmp)) {
         parsed.add(tmp);
-        output[key] = $.call(output, key, revive(input, parsed, tmp, $));
-      } else {
-        output[key] = $.call(output, key, tmp);
+        output[k] = ignore;
+        lazy.push({k, a: [input, parsed, tmp, $]});
       }
-    } else
-      output[key] = $.call(output, key, value);
+      else
+        output[k] = $.call(output, k, tmp);
+    }
+    else if (output[k] !== ignore)
+      output[k] = $.call(output, k, value);
+  }
+  for (let {length} = lazy, i = 0; i < length; i++) {
+    const {k, a} = lazy[i];
+    output[k] = $.call(output, k, revive.apply(null, a));
   }
   return output;
 };

index.js

@@ -11,6 +11,7 @@ self.Flatted = (function (exports) {
 
   var primitive = 'string'; // it could be 'number'
 
+  var ignore = {};
   var object = 'object';
 
   var noop = function noop(_, value) {
@@ -26,20 +27,31 @@ self.Flatted = (function (exports) {
   };
 
   var revive = function revive(input, parsed, output, $) {
+    var lazy = [];
+
     for (var ke = keys(output), length = ke.length, y = 0; y < length; y++) {
-      var key = ke[y];
-      var value = output[key];
+      var k = ke[y];
+      var value = output[k];
 
       if (value instanceof Primitive) {
         var tmp = input[value];
 
         if (typeof(tmp) === object && !parsed.has(tmp)) {
           parsed.add(tmp);
-          output[key] = $.call(output, key, revive(input, parsed, tmp, $));
-        } else {
-          output[key] = $.call(output, key, tmp);
-        }
-      } else output[key] = $.call(output, key, value);
+          output[k] = ignore;
+          lazy.push({
+            k: k,
+            a: [input, parsed, tmp, $]
+          });
+        } else output[k] = $.call(output, k, tmp);
+      } else if (output[k] !== ignore) output[k] = $.call(output, k, value);
+    }
+
+    for (var _length = lazy.length, i = 0; i < _length; i++) {
+      var _lazy$i = lazy[i],
+          _k = _lazy$i.k,
+          a = _lazy$i.a;
+      output[_k] = $.call(output, _k, revive.apply(null, a));
     }
 
     return output;