From 306727cd2370ef73a629bd3c74e6d702886cf0f4 Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Tue, 20 Aug 2024 15:49:34 -0500
Subject: [PATCH] Tweak example

---
 R/superseded-map-df.R | 35 ++++++++++++++---------------------
 man/map_dfr.Rd        | 35 ++++++++++++++---------------------
 2 files changed, 28 insertions(+), 42 deletions(-)

diff --git a/R/superseded-map-df.R b/R/superseded-map-df.R
index a0df6a72..7d527a5e 100644
--- a/R/superseded-map-df.R
+++ b/R/superseded-map-df.R
@@ -41,31 +41,24 @@
 #'   map(\(mod) as.data.frame(t(as.matrix(coef(mod))))) |>
 #'   list_rbind()
 #'
-#' # map: combining vectors ---------------------------
-#' DF <- structure(
-#' list(
-#'   `Column A` = c(" 13", "  15 "),
-#'   `Column B` = c("  34",  " 67 ")
-#' ),
-#' class = c("data.frame"),
-#' row.names = c(NA, -2L)
+#' # for certain pathological inputs `map_dfr()` and `map_dfc()` actually
+#' # both combine the list by column
+#' df <- data.frame(
+#'   x = c(" 13", "  15 "),
+#'   y = c("  34",  " 67 ")
 #' )
 #'
 #' # Was:
-#' # map_dfr() and map_dfc() actually both combine the list by column
-#' map_dfr(DF, trimws)
-#' map_dfc(DF, trimws)
+#' map_dfr(df, trimws)
+#' map_dfc(df, trimws)
 #'
-#' # Now:
-#' # to combine a list of vectors use as_tibble()
-#' map(DF, trimws) |> tibble::as_tibble()
-#'
-#' # list_rbind()/list_cbind() require list of data.frames or NULL to work and
-#' # will throw an error
-#' \dontrun{
-#'   map(DF, trimws) |> list_rbind()
-#'   map(DF, trimws) |> list_cbind()
-#' }
+#' # If you want to apply a function to each column of a data frame
+#' # you might instead want to use modify:
+#' modify(df, trimws)
+#'
+#' # list_rbind()/list_cbind() don't work here because they require
+#' # data frame inputs
+#' try(map(df, trimws) |> list_rbind())
 #'
 #' # map2 ---------------------------------------------
 #'
diff --git a/man/map_dfr.Rd b/man/map_dfr.Rd
index d4f17e3d..d92314de 100644
--- a/man/map_dfr.Rd
+++ b/man/map_dfr.Rd
@@ -71,31 +71,24 @@ mtcars |>
   map(\(mod) as.data.frame(t(as.matrix(coef(mod))))) |>
   list_rbind()
 
-# map: combining vectors ---------------------------
-DF <- structure(
-list(
-  `Column A` = c(" 13", "  15 "),
-  `Column B` = c("  34",  " 67 ")
-),
-class = c("data.frame"),
-row.names = c(NA, -2L)
+# for certain pathological inputs `map_dfr()` and `map_dfc()` actually
+# both combine the list by column
+df <- data.frame(
+  x = c(" 13", "  15 "),
+  y = c("  34",  " 67 ")
 )
 
 # Was:
-# map_dfr() and map_dfc() actually both combine the list by column
-map_dfr(DF, trimws)
-map_dfc(DF, trimws)
+map_dfr(df, trimws)
+map_dfc(df, trimws)
 
-# Now:
-# to combine a list of vectors use as_tibble()
-map(DF, trimws) |> tibble::as_tibble()
-
-# list_rbind()/list_cbind() require list of data.frames or NULL to work and
-# will throw an error
-\dontrun{
-  map(DF, trimws) |> list_rbind()
-  map(DF, trimws) |> list_cbind()
-}
+# If you want to apply a function to each column of a data frame
+# you might instead want to use modify:
+modify(df, trimws)
+
+# list_rbind()/list_cbind() don't work here because they require
+# data frame inputs
+try(map(df, trimws) |> list_rbind())
 
 # map2 ---------------------------------------------