WIP array methods for objects

lib/object.js

@@ -20,10 +20,19 @@ function cmp(a, b) {
   throw new Error('cannot effectively compare values');
 }
 
+function compact(o) {
+  return reduce(o, function(p, key) {
+    var val = o[key];
+    if (val !== null && val !== undefined) p[key] = val;
+    return p;
+  }, {});
+}
+
 function extend(a, b) {
   Object.getOwnPropertyNames(b).forEach(function(k) {
     a[k] = b[k];
   });
+  return a;
 }
 
 function extendPrototype(obj, ext) {
@@ -38,6 +47,49 @@ function extendPrototype(obj, ext) {
   });
 }
 
+function flatten(o) {
+  return reduce(o, function(p, key) {
+    var val = o[key];
+    if (val && !Array.isArray(val) && typeof val.flatten === 'function') {
+      extend(p, val.flatten());
+    }
+    else if (typeof val === 'object' && !Array.isArray(val)) {
+      extend(p, flatten(val));
+    }
+    else {
+      p[key] = val;
+    }
+    return p;
+  });
+}
+function grep(o, regex) {
+
+  return reduce(o, function(p, key) {
+    if (regex.test(key)) p[key] = o[key];
+    return p;
+  }, {});
+}
+
+function grepValues(o, regex) {
+  return reduce(o, function(p, key) {
+    var val = o[key];
+    if (regex.test(val)) p[key] = val;
+    return p;
+  });
+}
+
+function map(o, fn) {
+  return reduce(o, function(p, key) {
+    p[key] = fn(o[key], p, o);
+    return p;
+  });
+}
+
+function reduce(o, fn, initial) {
+  var keys = Object.getOwnPropertyNames(o || {});
+  return keys.reduce(fn, initial || {});
+}
+
 // Make a wrapper than passes `this` as the first argument, Python style. All
 // extension functions that can extend native types must follow this convention.
 function methodWrapper(fn) {