New function f_pull.

NAMESPACE

@@ -57,6 +57,7 @@ export(f_group_by)
 export(f_inner_join)
 export(f_left_join)
 export(f_nest_by)
+export(f_pull)
 export(f_rename)
 export(f_right_join)
 export(f_rowwise)

NEWS.md

@@ -18,6 +18,9 @@ in the list over environment objects.
 evaluates its argument dynamically unless the data is grouped and the 
 expressions supplied aren't simply column selections.
 
+- New function `f_pull` as a fast convenience function for extracting 
+vectors from columns.
+
 - `f_arrange` gains the `.descending` argument to efficiently 
 return data frames in descending order.
 

R/abc.R

@@ -20,6 +20,7 @@ which_in <- get_from_package("which_in", "cheapr")
 cpp_int64_to_numeric <- get_from_package("cpp_int64_to_numeric", "cheapr")
 cpp_loc_set_replace <- get_from_package("cpp_loc_set_replace", "cheapr")
 named_list <- get_from_package("named_list", "cheapr")
+`%in_%` <- cheapr::`%in_%`
 
 check_length <- function(x, size){
   if (length(x) != size){
@@ -60,8 +61,10 @@ col_select_pos <- function(data, .cols = character()){
   if (is.null(out_nms)){
     names(out) <- .subset(data_nms, out)
   } else {
-    es <- !nzchar(out_nms)
-    out_nms[es] <- .subset(data_nms, .subset(out, es))
+    es <- empty_str_locs(out_nms)
+    if (length(es)){
+      out_nms[es] <- .subset(data_nms, .subset(out, es))
+    }
     names(out) <- out_nms
   }
   out

R/f_select.R

@@ -1,4 +1,4 @@
-#' Fast `dplyr::select()`/`dplyr::rename()`
+#' Fast 'dplyr' `select()`/`rename()`/`pull()`
 #'
 #' @description
 #' `f_select()` operates the exact same way as `dplyr::select()` and
@@ -116,4 +116,13 @@ f_rename.data.table <- function(data, ..., .cols = NULL){
 }
 #' @rdname f_select
 #' @export
+f_pull <- function(data, ..., .cols = NULL){
+  col <- tidy_select_pos(data, ..., .cols = .cols)
+  if (length(col) != 1){
+    stop("You must select exactly one column in `f_pull()`")
+  }
+  .subset2(data, col)
+}
+#' @rdname f_select
+#' @export
 nothing <- function() character()

R/tidy_utils.R

@@ -132,13 +132,10 @@ tidy_select_pos <- function(data, ..., .cols = NULL){
   if (!is.null(.cols)){
     out <- col_select_pos(data, .cols)
   } else {
-    dots <- rlang::enquos(...)
-    labels <- quo_labels(dots)
-    if (all(labels %in% names(data))){
-      out <- add_names(match(labels, names(data)), names(labels))
-      # if (is.null(names(out))){
-      #   names(out) <- labels
-      # }
+    dots <- rlang::quos(...)
+    labels <- quo_labels(dots, named = TRUE)
+    if (all(labels %in_% data_nms)){
+      out <- add_names(match(labels, data_nms), names(labels))
       is_dup <- collapse::fduplicated(list(names(out), unname(out)))
       out <- out[!is_dup]
       if (anyDuplicated(names(out))){