Add Enumerable#index_by

opal · Mar 20, 2014 · 81b8325 · 81b8325
1 parent 1f24442
commit 81b8325
Showing 1 changed file with 32 additions and 0 deletions.
diff --git a/opal/active_support/core_ext/enumerable.rb b/opal/active_support/core_ext/enumerable.rb
@@ -0,0 +1,32 @@
+module Enumerable
+  def index_by(&block)
+    return enum_for :index_by unless block_given?
+
+    hash = Hash.new
+
+    %x{
+      var result;
+
+      self.$each._p = function() {
+        var param = #{Opal.destructure(`arguments`)},
+            value = $opal.$yield1(block, param);
+
+        if (value === $breaker) {
+          result = $breaker.$v;
+          return $breaker;
+        }
+
+        #{hash[`value`] = `param`};
+      }
+
+      self.$each();
+
+      if (result !== undefined) {
+        return result;
+      }
+    }
+
+    hash
+  end
+
+end