Rbind allow binding of different class attributes

NEWS.md

@@ -40,6 +40,10 @@
 
 14. `fread` loads `.bgz` files directly, [#5461](https://github.com/Rdatatable/data.table/issues/5461). Thanks to @TMRHarrison for the request with proposed fix, and Benjamin Schwendinger for the PR.
 
+15. `rbindlist(l, use.names=TRUE)` and `rbind` now works correctly on columns with different class attributes for certain classes such as `Date`, `IDate`, `ITime`, `POSIXct` and `AsIs` with other columns of similar classes, e.g., `IDate` and `Date`. The conversion is done automatically and the class attribute of the final column is determined by the first encountered class attribute in the binding list, [#5309](https://github.com/Rdatatable/data.table/issues/5309), [#4934](https://github.com/Rdatatable/data.table/issues/4934), [#5391](https://github.com/Rdatatable/data.table/issues/5391).
+
+`rbindlist(l, ignore.attr=TRUE)` and `rbind` also gains argument `ignore.attr` to manually deactivate the safety-net of binding columns with different column classes, [#3911](https://github.com/Rdatatable/data.table/issues/3911), [#5542](https://github.com/Rdatatable/data.table/issues/5542). Thanks to @dcaseykc, @fox34, @adrian-quintario, @berg-michael, @arunsrinivasan, @statquant, @pkress, @jrausch12, @therosko, @OfekShilon, @iMissile, @tdhock for the request and @ben-schwen for the PR.
+
 ## BUG FIXES
 
 1. `unique()` returns a copy the case when `nrows(x) <= 1` instead of a mutable alias, [#5932](https://github.com/Rdatatable/data.table/pull/5932). This is consistent with existing `unique()` behavior when the input has no duplicates but more than one row. Thanks to @brookslogan for the report and @dshemetov for the fix.

R/data.table.R

@@ -2737,14 +2737,14 @@ chgroup = function(x) {
 }
 
 # plain rbind and cbind methods are registered using S3method() in NAMESPACE only from R>=4.0.0; #3948
-rbind.data.table = function(..., use.names=TRUE, fill=FALSE, idcol=NULL) {
+rbind.data.table = function(..., use.names=TRUE, fill=FALSE, idcol=NULL, ignore.attr=FALSE) {
   l = lapply(list(...), function(x) if (is.list(x)) x else as.data.table(x))  #1626; e.g. psych binds a data.frame|table with a matrix
-  rbindlist(l, use.names, fill, idcol)
+  rbindlist(l, use.names, fill, idcol, ignore.attr)
 }
 cbind.data.table = data.table
 .rbind.data.table = rbind.data.table  # the workaround using this in FAQ 2.24 is still applied to support R < 4.0.0
 
-rbindlist = function(l, use.names="check", fill=FALSE, idcol=NULL) {
+rbindlist = function(l, use.names="check", fill=FALSE, idcol=NULL, ignore.attr=FALSE) {
   if (is.null(l)) return(null.data.table())
   if (!is.list(l) || is.data.frame(l)) stopf("Input is %s but should be a plain list of items to be stacked", class(l)[1L])
   if (isFALSE(idcol)) { idcol = NULL }
@@ -2760,7 +2760,7 @@ rbindlist = function(l, use.names="check", fill=FALSE, idcol=NULL) {
     if (!miss) stopf("use.names='check' cannot be used explicitly because the value 'check' is new in v1.12.2 and subject to change. It is just meant to convey default behavior. See ?rbindlist.")
     use.names = NA
   }
-  ans = .Call(Crbindlist, l, use.names, fill, idcol)
+  ans = .Call(Crbindlist, l, use.names, fill, idcol, ignore.attr)
   if (!length(ans)) return(null.data.table())
   setDT(ans)[]
 }

R/merge.R

@@ -96,21 +96,7 @@ merge.data.table = function(x, y, by = NULL, by.x = NULL, by.y = NULL, all = FAL
   if (all.y && nrow(y)) {  # If y does not have any rows, no need to proceed
     # Perhaps not very commonly used, so not a huge deal that the join is redone here.
     missingyidx = y[!x, which=TRUE, on=by, allow.cartesian=allow.cartesian]
-    # TO DO: replace by following once #5446 is merged
-    # if (length(missingyidx)) dt = rbind(dt, y[missingyidx], use.names=FALSE, fill=TRUE, ignore.attr=TRUE)
-    if (length(missingyidx)) {
-      yy = y[missingyidx]
-      othercolsx = setdiff(nm_x, by)
-      if (length(othercolsx)) {
-        # create NA rectangle with correct types and attributes of x to cbind to y
-        tmp = rep.int(NA_integer_, length(missingyidx))
-        # TO DO: use set() here instead..
-        yy = cbind(yy, x[tmp, othercolsx, with = FALSE])
-      }
-      # empty data.tables (nrow =0, ncol>0) doesn't skip names anymore in new rbindlist
-      # takes care of #24 without having to save names. This is how it should be, IMHO.
-      dt = rbind(dt, yy, use.names=FALSE)
-    }
+    if (length(missingyidx)) dt = rbind(dt, y[missingyidx], use.names=FALSE, fill=TRUE, ignore.attr=TRUE)
   }
   # X[Y] syntax puts JIS i columns at the end, merge likes them alongside i.
   newend = setdiff(nm_y, by.y)

inst/tests/other.Rraw

@@ -699,6 +699,14 @@ if (loaded[["nanotime"]]) {
   DT = data.table(time=nanotime(c(1,NA,3)))
   test(27, na.omit(DT), DT[c(1,3)])
 
+  # rbind with vectors with class attributes #5309
+  x = data.table(a=1L, b=as.nanotime(0))
+  y = data.table(a=2L, b=NA)
+  test(27.01, rbind(x,y), data.table(a = c(1L, 2L), b=as.nanotime(c(0, NA))))
+  test(27.02, rbind(y,x), data.table(a = c(2L, 1L), b=as.nanotime(c(NA, 0))))
+  y[, b := NULL]
+  test(27.03, rbind(x,y, fill = TRUE), data.table(a = c(1L, 2L), b=as.nanotime(c(0, NA))))
+  test(27.04, rbind(y,x, fill = TRUE), data.table(a = c(2L, 1L), b=as.nanotime(c(NA, 0))))
 }
 
 # that plot works; moved from tests.Rraw 167 to here to save ram of loading graphics package and possible screen device issues on overloaded servers, #5517

inst/tests/tests.Rraw

@@ -14435,6 +14435,8 @@ test(2003.81, rbind(x, y, fill=TRUE, use.names=TRUE), ans)
 test(2003.82, rbind(y, x, fill=TRUE, use.names=TRUE), ans[2:1,])
 test(2003.83, rbind(x, y, fill=TRUE, use.names=FALSE), ans)
 test(2003.84, rbind(y, x, fill=TRUE, use.names=FALSE), ans[2:1,])
+# rbindlist ignore attributes #3911
+test(2003.85, rbindlist(list(), ignore.attr=1), error="ignore.attr= should be TRUE or FALSE")
 
 # chmatch coverage for two different non-ascii encodings matching; issues mentioned in comments in chmatch.c #69 #2538 #111
 x1 = "fa\xE7ile"
@@ -18732,3 +18734,48 @@ x = list(
 N = 5e4
 y = x[rep(1:5, N)]
 test(2268, rbindlist(y, fill=TRUE), rbindlist(x, fill=TRUE)[rep(1:5, N)])
+
+# rbind with vectors with class attributes #5309
+x = data.table(a = 1L, b = as.Date("2020-01-01"))
+y = data.table(a = 2L, b = as.IDate("2021-01-01"))
+z = data.table(a = 3L, b = NA)
+test(2269.01, rbind(x, y), data.table(a=c(1L, 2L), b= as.Date(c("2020-01-01", "2021-01-01"))))
+test(2269.02, rbind(y, x), data.table(a=c(2L, 1L), b=as.IDate(c("2021-01-01", "2020-01-01"))))
+test(2269.03, rbind(x, z), data.table(a=c(1L, 3L), b= as.Date(c("2020-01-01", NA))))
+test(2269.04, rbind(z, x), data.table(a=c(3L, 1L), b= as.Date(c(NA,           "2020-01-01"))))
+test(2269.05, rbind(y, z), data.table(a=c(2L, 3L), b=as.IDate(c("2021-01-01", NA))))
+test(2269.06, rbind(z, y), data.table(a=c(3L, 2L), b=as.IDate(c(NA,           "2021-01-01"))))
+z[, b := NULL]
+test(2269.07, rbind(x, z, fill=TRUE), data.table(a=c(1L, 3L), b= as.Date(c("2020-01-01", NA))))
+test(2269.08, rbind(z, x, fill=TRUE), data.table(a=c(3L, 1L), b= as.Date(c(NA, "2020-01-01"))))
+test(2269.09, rbind(y, z, fill=TRUE), data.table(a=c(2L, 3L), b=as.IDate(c("2021-01-01", NA))))
+test(2269.10, rbind(z, y, fill=TRUE), data.table(a=c(3L, 2L), b=as.IDate(c(NA, "2021-01-01"))))
+x = data.table(a=1L, b=as.POSIXct("2021-10-06 13:58:00 UTC"))
+test(2269.11, rbind(x, z, fill=TRUE), data.table(a=c(1L, 3L), b=as.POSIXct(c("2021-10-06 13:58:00 UTC", NA))))
+test(2269.12, rbind(z, x, fill=TRUE), data.table(a=c(3L, 1L), b=as.POSIXct(c(NA, "2021-10-06 13:58:00 UTC"))))
+x = data.table(c=1L, d=as.POSIXct("2021-10-06 13:58:00 UTC"))
+test(2269.13, rbind(x, z, fill=TRUE, use.names=FALSE), data.table(c = c(1L, 3L), d=as.POSIXct(c("2021-10-06 13:58:00 UTC", NA))))
+test(2269.14, rbind(z, x, fill=TRUE, use.names=FALSE), data.table(a=c(3L, 1L), d=as.POSIXct(c(NA, "2021-10-06 13:58:00 UTC"))))
+x = data.table(a=1L, b=as.ITime(0))
+y = data.table(a=2L, b=NA)
+test(2269.15, rbind(x,y), data.table(a = c(1L, 2L), b=as.ITime(c(0, NA))))
+test(2269.16, rbind(y,x), data.table(a = c(2L, 1L), b=as.ITime(c(NA, 0))))
+y[, b := NULL]
+test(2269.17, rbind(x,y, fill = TRUE), data.table(a = c(1L, 2L), b=as.ITime(c(0, NA))))
+test(2269.18, rbind(y,x, fill = TRUE), data.table(a = c(2L, 1L), b=as.ITime(c(NA, 0))))
+# follow up to #5263 to simplify merge logic
+x = data.table(a = 1L, b = as.Date("2020-01-01"))
+y = data.table(a = 2L, b = NA)
+test(2269.19, merge(x, y, by="a", all=TRUE), data.table(a=1:2, b.x=as.Date(c("2020-01-01", NA)), b.y=NA, key="a"))
+test(2269.20, merge(y, x, by="a", all=TRUE), data.table(a=1:2, b.x=NA, key="a", b.y=as.Date(c("2020-01-01", NA))))
+# rbindlist with AsIs
+x = data.table(a = 1L, b=I(3L))
+y = data.table(a = 2L, b=4)
+test(2269.21, rbindlist(list(x,y)), data.table(a = c(1L, 2L), b=I(c(3L, 4))))
+test(2269.22, rbindlist(list(y,x)), data.table(a = c(2L, 1L), b=c(4, 3)))
+# rbind ignore attributes #3911
+x = data.table(a = structure(1:2, class=c("a", "integer")), key="a")
+y = data.table(a = 2:3, key="a")
+test(2269.31, merge(x,y, all.y=TRUE), data.table(a=structure(2:3, class=c("a", "integer")), key="a"))
+test(2269.32, rbind(x,y), error="Class attribute .* does not match with .*")
+test(2269.33, rbind(x,y, ignore.attr=TRUE), data.table(a=structure(c(1L, 2L, 2L, 3L), class=c("a", "integer"))))

man/rbindlist.Rd

@@ -7,14 +7,15 @@
   Same as \code{do.call(rbind, l)} on \code{data.frame}s, but much faster.
 }
 \usage{
-rbindlist(l, use.names="check", fill=FALSE, idcol=NULL)
+rbindlist(l, use.names="check", fill=FALSE, idcol=NULL, ignore.attr=FALSE)
 # rbind(..., use.names=TRUE, fill=FALSE, idcol=NULL)
 }
 \arguments{
   \item{l}{ A list containing \code{data.table}, \code{data.frame} or \code{list} objects. \code{\dots} is the same but you pass the objects by name separately. }
   \item{use.names}{\code{TRUE} binds by matching column name, \code{FALSE} by position. `check` (default) warns if all items don't have the same names in the same order and then currently proceeds as if `use.names=FALSE` for backwards compatibility (\code{TRUE} in future); see news for v1.12.2.}
   \item{fill}{\code{TRUE} fills missing columns with NAs, or NULL for missing list columns. By default \code{FALSE}.}
   \item{idcol}{Creates a column in the result showing which list item those rows came from. \code{TRUE} names this column \code{".id"}. \code{idcol="file"} names this column \code{"file"}. If the input list has names, those names are the values placed in this id column, otherwise the values are an integer vector \code{1:length(l)}. See \code{examples}.}
+  \item{ignore.attr}{Logical, default \code{FALSE}. When \code{TRUE}, allows binding columns with different attributes (e.g. class).}
 }
 \details{
 Each item of \code{l} can be a \code{data.table}, \code{data.frame} or \code{list}, including \code{NULL} (skipped) or an empty object (0 rows). \code{rbindlist} is most useful when there are an unknown number of (potentially many) objects to stack, such as returned by \code{lapply(fileNames, fread)}. \code{rbind} is most useful to stack two or three objects which you know in advance. \code{\dots} should contain at least one \code{data.table} for \code{rbind(\dots)} to call the fast method and return a \code{data.table}, whereas \code{rbindlist(l)} always returns a \code{data.table} even when stacking a plain \code{list} with a \code{data.frame}, for example.
@@ -54,6 +55,11 @@ rbindlist(l, use.names=TRUE, fill=TRUE, idcol=TRUE)
 setattr(l, 'names', c("a", "b"))
 rbindlist(l, use.names=TRUE, fill=TRUE, idcol="ID")
 
+# bind different classes
+DT1 = data.table(A=1:3,B=letters[1:3])
+DT2 = data.table(A=4:5,B=letters[4:5])
+setattr(DT1[["A"]], "class", c("a", "integer"))
+rbind(DT1, DT2, ignore.attr=TRUE)
 }
 \keyword{ data }
 

src/data.table.h

@@ -93,6 +93,7 @@ extern SEXP char_datatable;
 extern SEXP char_dataframe;
 extern SEXP char_NULL;
 extern SEXP char_maxString;
+extern SEXP char_AsIs;
 extern SEXP sym_sorted;
 extern SEXP sym_index;
 extern SEXP sym_BY;
@@ -286,7 +287,7 @@ SEXP chmatchdup_R(SEXP, SEXP, SEXP);
 SEXP chin_R(SEXP, SEXP);
 SEXP freadR(SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP);
 SEXP fwriteR(SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP, SEXP);
-SEXP rbindlist(SEXP, SEXP, SEXP, SEXP);
+SEXP rbindlist(SEXP, SEXP, SEXP, SEXP, SEXP);
 SEXP setlistelt(SEXP, SEXP, SEXP);
 SEXP address(SEXP);
 SEXP expandAltRep(SEXP);

src/init.c

@@ -23,6 +23,7 @@ SEXP char_datatable;
 SEXP char_dataframe;
 SEXP char_NULL;
 SEXP char_maxString;
+SEXP char_AsIs;
 SEXP sym_sorted;
 SEXP sym_index;
 SEXP sym_BY;
@@ -260,6 +261,7 @@ void attribute_visible R_init_data_table(DllInfo *info)
   char_dataframe = PRINTNAME(install("data.frame"));
   char_NULL =      PRINTNAME(install("NULL"));
   char_maxString = PRINTNAME(install("\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"));
+  char_AsIs =      PRINTNAME(install("AsIs"));
 
   if (TYPEOF(char_integer64) != CHARSXP) {
     // checking one is enough in case of any R-devel changes

src/rbindlist.c

@@ -2,16 +2,19 @@
 #include <Rdefines.h>
 #include <ctype.h>   // for isdigit
 
-SEXP rbindlist(SEXP l, SEXP usenamesArg, SEXP fillArg, SEXP idcolArg)
+SEXP rbindlist(SEXP l, SEXP usenamesArg, SEXP fillArg, SEXP idcolArg, SEXP ignoreattrArg)
 {
   if (!isLogical(fillArg) || LENGTH(fillArg) != 1 || LOGICAL(fillArg)[0] == NA_LOGICAL)
     error(_("%s should be TRUE or FALSE"), "fill");
   if (!isLogical(usenamesArg) || LENGTH(usenamesArg)!=1)
     error(_("use.names= should be TRUE, FALSE, or not used (\"check\" by default)"));  // R levels converts "check" to NA
+  if (!isLogical(ignoreattrArg) || LENGTH(ignoreattrArg)!=1 || LOGICAL(ignoreattrArg)[0] == NA_LOGICAL)
+    error(_("ignore.attr= should be TRUE or FALSE"));
   if (!length(l)) return(l);
   if (TYPEOF(l) != VECSXP) error(_("Input to rbindlist must be a list. This list can contain data.tables, data.frames or plain lists."));
   Rboolean usenames = LOGICAL(usenamesArg)[0];
   const bool fill = LOGICAL(fillArg)[0];
+  const bool ignoreattr = LOGICAL(ignoreattrArg)[0];
   if (fill && usenames==NA_LOGICAL) {
     usenames=TRUE;
   }
@@ -274,7 +277,7 @@ SEXP rbindlist(SEXP l, SEXP usenamesArg, SEXP fillArg, SEXP idcolArg)
     bool factor=false, orderedFactor=false;     // ordered factor is class c("ordered","factor"). isFactor() is true when isOrdered() is true.
     int longestLen=-1, longestW=-1, longestI=-1; // just for ordered factor; longestLen must be initialized as -1 so that rbind zero-length ordered factor could work #4795
     SEXP longestLevels=R_NilValue;              // just for ordered factor
-    bool int64=false;
+    bool int64=false, date=false, posixct=false, itime=false, asis=false;
     const char *foundName=NULL;
     bool anyNotStringOrFactor=false;
     SEXP firstCol=R_NilValue;
@@ -305,14 +308,25 @@ SEXP rbindlist(SEXP l, SEXP usenamesArg, SEXP fillArg, SEXP idcolArg)
       if (INHERITS(thisCol, char_integer64)) {
         if (firsti>=0 && !length(getAttrib(firstCol, R_ClassSymbol))) { firsti=i; firstw=w; firstCol=thisCol; } // so the integer64 attribute gets copied to target below
         int64=true;
+      } else if (INHERITS(thisCol, char_Date))  {
+        if (firsti>=0 && !length(getAttrib(firstCol, R_ClassSymbol))) { firsti=i; firstw=w; firstCol=thisCol; }
+        date=true;
+      } else if (INHERITS(thisCol, char_POSIXct))  {
+        if (firsti>=0 && !length(getAttrib(firstCol, R_ClassSymbol))) { firsti=i; firstw=w; firstCol=thisCol; }
+        posixct=true;
+      } else if (INHERITS(thisCol, char_ITime)) {
+        if (firsti>=0 && !length(getAttrib(firstCol, R_ClassSymbol))) { firsti=i; firstw=w; firstCol=thisCol; }
+        itime=true;
+      } else if (!asis && INHERITS(thisCol, char_AsIs)) {
+        asis=true;
       }
       if (firsti==-1) { firsti=i; firstw=w; firstCol=thisCol; }
       else {
-        if (!factor && !int64) {
+        if (!factor && !int64 && ((!date && !posixct) || (date && posixct)) && !itime &!asis) { // prohibit binding of date and posixct
           if (!R_compute_identical(PROTECT(getAttrib(thisCol, R_ClassSymbol)),
                                    PROTECT(getAttrib(firstCol, R_ClassSymbol)),
-                                   0)) {
-            error(_("Class attribute on column %d of item %d does not match with column %d of item %d."), w+1, i+1, firstw+1, firsti+1);
+                                   0) && !ignoreattr) {
+            error(_("Class attribute on column %d of item %d does not match with column %d of item %d. You can deactivate this safety-check by using ignore.attr=TRUE"), w+1, i+1, firstw+1, firsti+1);
           }
           UNPROTECT(2);
         }
@@ -323,6 +337,7 @@ SEXP rbindlist(SEXP l, SEXP usenamesArg, SEXP fillArg, SEXP idcolArg)
     if (factor) maxType=INTSXP;  // if any items are factors then a factor is created (could be an option)
     if (int64 && maxType!=REALSXP)
       error(_("Internal error: column %d of result is determined to be integer64 but maxType=='%s' != REALSXP"), j+1, type2char(maxType)); // # nocov
+    if (date && INHERITS(firstCol, char_IDate)) maxType=INTSXP; // first encountered Date determines class and type #5309
     SEXP target;
     SET_VECTOR_ELT(ans, idcol+j, target=allocVector(maxType, nrow));  // does not initialize logical & numerics, but does initialize character and list
     if (!factor) copyMostAttrib(firstCol, target); // all but names,dim and dimnames; mainly for class. And if so, we want a copy here, not keepattr's SET_ATTRIB.