make rbind_all stricter (only accepting lists of data frames). closes #…

…288

NEWS.md

@@ -7,6 +7,8 @@
 * `glimpse()` makes it possible to see all the columns in a tbl,
   displaying as much data for each variable as can be fit on a single line.
 
+* `rbind_all()` is stricter and only accepts list of data frames (#288)  
+
 ## Bug fixes
 
 * Code adapted to Rcpp > 0.11.1

inst/include/tools/FilteredListOf.h

@@ -0,0 +1,31 @@
+#ifndef dplyr_tools_FilteredListOf_H
+#define dplyr_tools_FilteredListOf_H
+
+namespace Rcpp {
+
+    template <typename T>
+    class FilteredListOf {
+    public: 
+
+        FilteredListOf(SEXP data_) : data(data_){
+          int n = data.size() ;
+          for( int i=0; i<n; i++){
+            indices.push_back(i) ;  
+          }
+        }
+
+        T operator[](int i) const { 
+            return as<T>( data[indices[i]]) ;
+        }
+
+        int size() const { 
+            return indices.size() ; 
+        }
+
+    private:
+        List data ;
+        std::vector<int> indices ;
+    } ;
+}
+
+#endif

inst/include/tools/StrictListOf.h

@@ -0,0 +1,37 @@
+#ifndef dplyr_tools_FilteredListOf_H
+#define dplyr_tools_FilteredListOf_H
+
+namespace Rcpp {
+
+    template <typename T>
+    class StrictListOf {
+    public: 
+
+        StrictListOf(SEXP data_) : data(data_){
+          int n = data.size() ;
+          for( int i=0; i<n; i++){
+            if( !is<T>(data[i]) ){
+              std::stringstream s ;
+              s << "object at index " 
+                << i 
+                << " not compatible with class "
+                << DEMANGLE(T) ;
+              stop( s.str() ) ;
+            }
+          }
+        }
+
+        T operator[](int i) const { 
+            return as<T>( data[i] ) ;
+        }
+
+        int size() const { 
+            return data.size() ; 
+        }
+
+    private:
+        List data ;
+    } ;
+}
+
+#endif

inst/include/tools/tools.h

@@ -6,6 +6,8 @@
 #include <tools/hash.h>
 #include <tools/delete_all.h>
 #include <tools/ListOf.h>
+#include <tools/StrictListOf.h>
+#include <tools/FilteredListOf.h>
 #include <tools/collapse.h>
 #include <tools/get_single_class.h>
 #include <tools/SlicingIndex.h>

inst/tests/test-rbind.r

@@ -90,3 +90,9 @@ test_that( "rbind handles NA in factors #279", {
   expect_equal(res$c, c("d","b"))
 
 })
+
+test_that( "rbind_all only accepts data frames #288",{
+  ll <- list(c(1,2,3,4, 5), c(6, 7, 8, 9, 10))
+  expect_error(rbind_all(ll))
+})
+

src/RcppExports.cpp

@@ -448,13 +448,13 @@ BEGIN_RCPP
 END_RCPP
 }
 // rbind_all
-List rbind_all(ListOf<DataFrame> dots);
+List rbind_all(StrictListOf<DataFrame> dots);
 RcppExport SEXP dplyr_rbind_all(SEXP dotsSEXP) {
 BEGIN_RCPP
     SEXP __sexp_result;
     {
         Rcpp::RNGScope __rngScope;
-        Rcpp::traits::input_parameter< ListOf<DataFrame> >::type dots(dotsSEXP );
+        Rcpp::traits::input_parameter< StrictListOf<DataFrame> >::type dots(dotsSEXP );
         List __result = rbind_all(dots);
         PROTECT(__sexp_result = Rcpp::wrap(__result));
     }

src/dplyr.cpp

@@ -1549,7 +1549,7 @@ List rbind__impl( Dots dots ){
 //' @export
 //' @rdname rbind
 // [[Rcpp::export]]
-List rbind_all( ListOf<DataFrame> dots ){
+List rbind_all( StrictListOf<DataFrame> dots ){
     return rbind__impl(dots) ;
 }