started work on #35, extension packs

pkg/DESCRIPTION

@@ -1,7 +1,7 @@
 Package: plyrmr
 Type: Package
 Title: Data manipulation backed by rmr2 and Hadoop
-Version: 0.2.0
+Version: 0.3.0
 Date: 2014-03-31
 Author: Revolution Analytics
 Maintainer: Revolution Analytics <rhadoop@revolutionanalytics.com>
@@ -10,4 +10,4 @@ Depends: rmr2 (>= 3.1.0), reshape2, dplyr
 Imports: Rcpp (>= 0.10.4), plyr,  R.methodsS3, Hmisc, functional
 License: Apache License (== 2.0)
 LinkingTo: Rcpp
-Collate: RcppExports.R common.R  big.data.R pipe.R dataframe.R aggregate.R arrange-like.R base.R reshape2.R sqlish.R
+Collate: RcppExports.R common.R  big.data.R pipe.R dataframe.R aggregate.R arrange-like.R base.R reshape2.R sqlish.R extensions.R

pkg/NAMESPACE

@@ -105,6 +105,8 @@ S3method(dcast, pipe)
 S3method(dcast, default)
 S3method(melt, pipe)
 S3method(melt, data.frame)
+#other
+export(extend)
 #fast summaries
 #export(fast.summary)
 #S3method(fast.summary, pipe)

pkg/R/extensions.R

@@ -0,0 +1,26 @@
+# Copyright 2014 Revolution Analytics
+#    
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# 
+#      http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, 
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+extend = 
+	function(pack = c("base", "dplyr"), envir = parent.frame()) {
+		pack = match.arg(pack)
+		switch(
+			pack,
+			base = {
+				magic.wand(transform, TRUE, TRUE, envir = envir)
+				magic.wand(subset, TRUE, TRUE, envir = envir)},
+			dplyr = {
+				magic.wand(filter, TRUE, TRUE, envir = envir)
+				magic.wand(mutate, TRUE, TRUE, envir = envir)})}