use frev and setrev internally

Author: ben-schwen

R/as.data.table.R

@@ -36,11 +36,11 @@ as.data.table.table = function(x, keep.rownames=FALSE, key=NULL, ...) {
   # prevent #4179 & just cut out here
   if (any(dim(x) == 0L)) return(null.data.table())
   # Fix for bug #43 - order of columns are different when doing as.data.table(with(DT, table(x, y)))
-  val = rev(dimnames(provideDimnames(x)))
+  val = frev(dimnames(provideDimnames(x)))
   if (is.null(names(val)) || !any(nzchar(names(val))))
-    setattr(val, 'names', paste0("V", rev(seq_along(val))))
+    setattr(val, 'names', paste0("V", frev(seq_along(val))))
   ans = data.table(do.call(CJ, c(val, sorted=FALSE)), N = as.vector(x), key=key)
-  setcolorder(ans, c(rev(head(names(ans), -1L)), "N"))
+  setcolorder(ans, c(frev(head(names(ans), -1L)), "N"))
   ans
 }
 
@@ -101,18 +101,18 @@ as.data.table.array = function(x, keep.rownames=FALSE, key=NULL, sorted=TRUE, va
     dnx[nulldnx] = lapply(dx[nulldnx], seq_len) #3636
     dnx
   } else dnx
-  val = rev(val)
+  setrev(val)
   if (is.null(names(val)) || !any(nzchar(names(val))))
-    setattr(val, 'names', paste0("V", rev(seq_along(val))))
+    setattr(val, 'names', paste0("V", frev(seq_along(val))))
   if (value.name %chin% names(val))
-    stopf("Argument 'value.name' should not overlap with column names in result: %s", brackify(rev(names(val))))
+    stopf("Argument 'value.name' should not overlap with column names in result: %s", brackify(frev(names(val))))
   N = NULL
   ans = do.call(CJ, c(val, sorted=FALSE))
   set(ans, j="N", value=as.vector(x))
   if (isTRUE(na.rm))
     ans = ans[!is.na(N)]
   setnames(ans, "N", value.name)
-  dims = rev(head(names(ans), -1L))
+  dims = frev(head(names(ans), -1L))
   setcolorder(ans, c(dims, value.name))
   if (isTRUE(sorted) && is.null(key)) key = dims
   setkeyv(ans, key)

R/bmerge.R

@@ -110,7 +110,7 @@ bmerge = function(i, x, icols, xcols, roll, rollends, nomatch, mult, ops, verbos
     }
     if (x_merge_type=="integer64" || i_merge_type=="integer64") {
       nm = c(iname, xname)
-      if (x_merge_type=="integer64") { w=i; wc=icol; wclass=i_merge_type; } else { w=x; wc=xcol; wclass=x_merge_type; nm=rev(nm) }  # w is which to coerce
+      if (x_merge_type=="integer64") { w=i; wc=icol; wclass=i_merge_type; } else { w=x; wc=xcol; wclass=x_merge_type; setrev(nm) }  # w is which to coerce
       if (wclass=="integer" || (wclass=="double" && fitsInInt64(w[[wc]]))) {
         from_detail = if (wclass == "double") gettext(" (which has integer64 representation, e.g. no fractions)") else ""
         coerce_col(w, wc, wclass, "integer64", nm[1L], nm[2L], from_detail, verbose=verbose)

R/utils.R

@@ -86,7 +86,7 @@ which.last = function(x)
   if (!is.logical(x)) {
     stopf("x not boolean")
   }
-  length(x) - match(TRUE, rev(x)) + 1L
+  length(x) - match(TRUE, frev(x)) + 1L
 }
 
 require_bit64_if_needed = function(DT) {
@@ -226,7 +226,7 @@ fctr = function(x, levels=unique(x), ..., sort=FALSE, rev=FALSE) {
   if (!isTRUEorFALSE(rev))
     stopf("argument 'rev' must be TRUE or FALSE")
   if (sort) levels = sort(levels)
-  if (rev) levels = rev(levels)
+  if (rev) setrev(levels)
   factor(x, levels=levels, ...)
 }