feat(3611): added message and doc int64 column creation in fread

Author: manmita

R/fread.R

@@ -7,7 +7,8 @@ showProgress=getOption("datatable.showProgress",interactive()), data.table=getOp
 nThread=getDTthreads(verbose), logical01=getOption("datatable.logical01",FALSE),
 logicalYN=getOption("datatable.logicalYN", FALSE),
 keepLeadingZeros=getOption("datatable.keepLeadingZeros",FALSE),
-yaml=FALSE, tmpdir=tempdir(), tz="UTC")
+yaml=FALSE, tmpdir=tempdir(), tz="UTC",
+no.integer64.message=getOption("datatable.integer64.message", FALSE))
 {
   if (missing(input)+is.null(file)+is.null(text)+is.null(cmd) < 3L) stopf("Used more than one of the arguments input=, file=, text= and cmd=.")
   input_has_vars = length(all.vars(substitute(input)))>0L  # see news for v1.11.6
@@ -261,13 +262,26 @@ yaml=FALSE, tmpdir=tempdir(), tz="UTC")
     if (identical(tt,"") || is_utc(tt)) # empty TZ env variable ("") means UTC in C library, unlike R; _unset_ TZ means local
       tz="UTC"
   }
+
   ans = .Call(CfreadR,input,identical(input,file),sep,dec,quote,header,nrows,skip,na.strings,strip.white,blank.lines.skip,comment.char,
               fill,showProgress,nThread,verbose,warnings2errors,logical01,logicalYN,select,drop,colClasses,integer64,encoding,keepLeadingZeros,tz=="UTC")
   if (!length(ans)) return(null.data.table())  # test 1743.308 drops all columns
   nr = length(ans[[1L]])
   require_bit64_if_needed(ans)
   setattr(ans,"row.names",.set_row_names(nr))
 
+  # integer64 message on create - instead of warning
+  if (!isTRUE(no.integer64.message) &&
+      identical(integer64, "integer64") &&
+      any(vapply(ans, function(x) inherits(x, "integer64"), logical(1L)))) {
+    message(
+      "fread: Creating one or more integer64 columns. 
+      See ?fread and ?bit64::integer64.
+      To suppress this message, use no.integer64.message=TRUE.
+      To avoid integer64 columns, use options(datatable.integer64='numeric')."
+    )
+  }
+
   if (isTRUE(data.table)) {
     setattr(ans, "class", c("data.table", "data.frame"))
     setalloccol(ans)

man/fread.Rd

@@ -25,7 +25,11 @@ nThread=getDTthreads(verbose),
 logical01=getOption("datatable.logical01", FALSE),
 logicalYN=getOption("datatable.logicalYN", FALSE),
 keepLeadingZeros = getOption("datatable.keepLeadingZeros", FALSE),
-yaml=FALSE, tmpdir=tempdir(), tz="UTC"
+yaml=FALSE, tmpdir=tempdir(), tz="UTC",
+no.integer64.message=getOption("datatable.integer64.message", FALSE)
+  \item{no.integer64.message}{ Logical. If FALSE (default), fread will print a message when creating one or more integer64 columns, warning that this type is not fully supported in base R (e.g., as.matrix() will not work as expected). To suppress the message, set this argument to TRUE or use \code{options(datatable.integer64.message=TRUE)}. To avoid integer64 columns entirely, use \code{options(datatable.integer64='numeric')}. }
+\bold{integer64 columns:}
+If fread creates integer64 columns, it prints a message by default to inform the user.
 )
 }
 \arguments{