Add _.placeholder support so wrapped functions may support placeholders.

fp/_baseConvert.js

@@ -156,14 +156,15 @@ function baseConvert(util, name, func) {
     if (wrapper) {
       return wrapper(func);
     }
+    var wrapped = func;
     if (mutateMap.array[name]) {
-      func = immutWrap(func, cloneArray);
+      wrapped = immutWrap(func, cloneArray);
     }
     else if (mutateMap.object[name]) {
-      func = immutWrap(func, createCloner(func));
+      wrapped = immutWrap(func, createCloner(func));
     }
     else if (mutateMap.set[name]) {
-      func = immutWrap(func, cloneDeep);
+      wrapped = immutWrap(func, cloneDeep);
     }
     var result;
     each(mapping.caps, function(cap) {
@@ -174,8 +175,8 @@ function baseConvert(util, name, func) {
               spreadStart = mapping.methodSpread[name];
 
           result = spreadStart === undefined
-            ? ary(func, cap)
-            : spread(func, spreadStart);
+            ? ary(wrapped, cap)
+            : spread(wrapped, spreadStart);
 
           if (cap > 1 && !mapping.skipRearg[name]) {
             result = rearg(result, mapping.methodRearg[name] || mapping.aryRearg[cap]);
@@ -196,7 +197,7 @@ function baseConvert(util, name, func) {
 
     result || (result = func);
     if (mapping.placeholder[name]) {
-      result.placeholder = placeholder;
+      func.placeholder = result.placeholder = placeholder;
     }
     return result;
   };
@@ -204,8 +205,8 @@ function baseConvert(util, name, func) {
   if (!isLib) {
     return wrap(name, func);
   }
-  // Add placeholder alias.
-  _.__ = placeholder;
+  // Add placeholder.
+  _.placeholder = placeholder;
 
   // Iterate over methods for the current ary cap.
   var pairs = [];

fp/_mapping.js

@@ -1,5 +1,6 @@
 /** Used to map aliases to their real names. */
 exports.aliasToReal = {
+  '__': 'placeholder',
   'all': 'some',
   'allPass': 'overEvery',
   'apply': 'spread',

lodash.js

@@ -4122,7 +4122,7 @@
             index = length,
             args = Array(length),
             fn = (this && this !== root && this instanceof wrapper) ? Ctor : func,
-            placeholder = wrapper.placeholder;
+            placeholder = lodash.placeholder || wrapper.placeholder;
 
         while (index--) {
           args[index] = arguments[index];
@@ -4238,7 +4238,7 @@
           args = composeArgsRight(args, partialsRight, holdersRight);
         }
         if (isCurry || isCurryRight) {
-          var placeholder = wrapper.placeholder,
+          var placeholder = lodash.placeholder || wrapper.placeholder,
               argsHolders = replaceHolders(args, placeholder);
 
           length -= argsHolders.length;
@@ -8345,7 +8345,9 @@
     var bind = rest(function(func, thisArg, partials) {
       var bitmask = BIND_FLAG;
       if (partials.length) {
-        var holders = replaceHolders(partials, bind.placeholder);
+        var placeholder = lodash.placeholder || bind.placeholder,
+            holders = replaceHolders(partials, placeholder);
+
         bitmask |= PARTIAL_FLAG;
       }
       return createWrapper(func, bitmask, thisArg, partials, holders);
@@ -8398,7 +8400,9 @@
     var bindKey = rest(function(object, key, partials) {
       var bitmask = BIND_FLAG | BIND_KEY_FLAG;
       if (partials.length) {
-        var holders = replaceHolders(partials, bindKey.placeholder);
+        var placeholder = lodash.placeholder || bindKey.placeholder,
+            holders = replaceHolders(partials, placeholder);
+
         bitmask |= PARTIAL_FLAG;
       }
       return createWrapper(key, bitmask, object, partials, holders);
@@ -8447,7 +8451,7 @@
     function curry(func, arity, guard) {
       arity = guard ? undefined : arity;
       var result = createWrapper(func, CURRY_FLAG, undefined, undefined, undefined, undefined, undefined, arity);
-      result.placeholder = curry.placeholder;
+      result.placeholder = lodash.placeholder || curry.placeholder;
       return result;
     }
 
@@ -8491,7 +8495,7 @@
     function curryRight(func, arity, guard) {
       arity = guard ? undefined : arity;
       var result = createWrapper(func, CURRY_RIGHT_FLAG, undefined, undefined, undefined, undefined, undefined, arity);
-      result.placeholder = curryRight.placeholder;
+      result.placeholder = lodash.placeholder || curryRight.placeholder;
       return result;
     }
 
@@ -8913,7 +8917,9 @@
      * // => 'hi fred'
      */
     var partial = rest(function(func, partials) {
-      var holders = replaceHolders(partials, partial.placeholder);
+      var placeholder = lodash.placeholder || partial.placeholder,
+          holders = replaceHolders(partials, placeholder);
+
       return createWrapper(func, PARTIAL_FLAG, undefined, partials, holders);
     });
 
@@ -8949,7 +8955,9 @@
      * // => 'hello fred'
      */
     var partialRight = rest(function(func, partials) {
-      var holders = replaceHolders(partials, partialRight.placeholder);
+      var placeholder = lodash.placeholder || partialRight.placeholder,
+          holders = replaceHolders(partials, placeholder);
+
       return createWrapper(func, PARTIAL_RIGHT_FLAG, undefined, partials, holders);
     });