make it explicit that POSIXlt results are forbidden in mutate. closes #…

…670
tidyverse · Oct 13, 2014 · da44c79 · da44c79
1 parent 179032c
commit da44c79
Show file tree

Hide file tree

Showing 4 changed files with 24 additions and 0 deletions.
diff --git a/NEWS.md b/NEWS.md
@@ -26,6 +26,8 @@
 * Added class `JoinFactorFactorVisitor_SameLevels` for the special case when 
   two factors with the same levels (in the same order) are joined (#675). 
 
+* `mutate` forbids `POSIXlt` results (#670)  
+
 # dplyr 0.3.0.1
 
 * Fixed problem with test script on Windows.

diff --git a/inst/include/dplyr/Gatherer.h b/inst/include/dplyr/Gatherer.h
@@ -179,6 +179,9 @@ namespace dplyr {
 
     template <typename Data, typename Subsets>
     inline Gatherer* constant_gatherer(SEXP x, int n){
+        if( Rf_inherits(x, "POSIXlt" ) ){
+            stop("`mutate` does not support `POSIXlt` results");    
+        }
         switch( TYPEOF(x) ){
             case INTSXP: {
                     if( Rf_inherits(x, "Date" )) return new ConstantTypedGatherer<INTSXP,Data,Subsets>(x,n, get_date_classes() ) ;
@@ -204,6 +207,9 @@ namespace dplyr {
         typename Data::group_iterator git = gdf.group_begin() ;
         SlicingIndex indices = *git ;
         Shield<SEXP> first( proxy.get(indices) ) ;
+        if( Rf_inherits(first, "POSIXlt" ) ){
+            stop("`mutate` does not support `POSIXlt` results");    
+        }
         switch( TYPEOF(first) ){
             case INTSXP:  
                 {

diff --git a/src/dplyr.cpp b/src/dplyr.cpp
@@ -1889,6 +1889,9 @@ SEXP mutate_not_grouped(DataFrame df, const LazyDots& dots){
 
         check_supported_type(result, name) ;
 
+        if( Rf_inherits(result, "POSIXlt") ){
+            stop("`mutate` does not support `POSIXlt` results");    
+        }
         if( Rf_length(result) == df.nrows() ){
             // ok
         } else if( Rf_length(result) == 1 ){

diff --git a/tests/testthat/test-mutate.r b/tests/testthat/test-mutate.r
@@ -320,3 +320,16 @@ test_that("mutate handles using and gathering complex data (#436)", {
   expect_true( all(res$constant == 2+2i) )
 })
 
+test_that("mutate forbids POSIXlt results (#670)", {
+  expect_error( 
+    data.frame(time='2014/01/01 10:10:10') %>% mutate(time=as.POSIXlt(time)), 
+    "does not support" 
+  )
+
+  expect_error( 
+    data.frame(time='2014/01/01 10:10:10', a=2) %>% group_by(a) %>% mutate(time=as.POSIXlt(time)),
+    "does not support" 
+  )
+
+})
+