Include abbreviation in DateTime.to_string/1

Author: José Valim

lib/elixir/lib/calendar.ex

@@ -1184,7 +1184,7 @@ defmodule DateTime do
       ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
       ...>                utc_offset: 3600, std_offset: 3600, time_zone: "Europe/Warsaw"}
       iex> DateTime.to_string(dt)
-      "2000-02-29 23:00:07+02:00 Europe/Warsaw"
+      "2000-02-29 23:00:07+02:00 CEST Europe/Warsaw"
 
       iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "UTC",
       ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
@@ -1196,7 +1196,7 @@ defmodule DateTime do
       ...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
       ...>                utc_offset: -12600, std_offset: 3600, time_zone: "Brazil/Manaus"}
       iex> DateTime.to_string(dt)
-      "2000-02-29 23:00:07-02:30 Brazil/Manaus"
+      "2000-02-29 23:00:07-02:30 BRM Brazil/Manaus"
   """
   @spec to_string(DateTime.t) :: String.t
   def to_string(%DateTime{calendar: calendar} = dt) do

lib/elixir/lib/calendar/iso.ex

@@ -75,13 +75,13 @@ defmodule Calendar.ISO do
     date_to_string(year, month, day) <> " " <> time_to_string(hour, minute, second, microsecond)
   end
 
-  def to_string(%DateTime{year: year, month: month, day: day,
+  def to_string(%DateTime{year: year, month: month, day: day, zone_abbr: zone_abbr,
                           hour: hour, minute: minute, second: second, microsecond: microsecond,
                           utc_offset: utc_offset, std_offset: std_offset, time_zone: time_zone}) do
     date_to_string(year, month, day) <> " " <>
       time_to_string(hour, minute, second, microsecond) <>
       offset_to_string(utc_offset, std_offset, time_zone) <>
-      zone_to_string(utc_offset, std_offset, time_zone)
+      zone_to_string(utc_offset, std_offset, zone_abbr, time_zone)
   end
 
   defp date_to_string(year, month, day) do
@@ -108,8 +108,8 @@ defmodule Calendar.ISO do
     sign(total) <> zero_pad(hour, 2) <> ":" <> zero_pad(minute, 2)
   end
 
-  defp zone_to_string(0, 0, "Etc/UTC"), do: ""
-  defp zone_to_string(_, _, zone), do: " " <> zone
+  defp zone_to_string(0, 0, _abbr, "Etc/UTC"), do: ""
+  defp zone_to_string(_, _, abbr, zone), do: " " <> abbr <> " " <> zone
 
   defp sign(total) when total < 0, do: "-"
   defp sign(_), do: "+"

lib/elixir/test/elixir/calendar_test.exs

@@ -64,6 +64,6 @@ defmodule DateTimeTest do
     dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "BRM",
                    hour: 23, minute: 0, second: 7, microsecond: {0, 0},
                    utc_offset: -12600, std_offset: 3600, time_zone: "Brazil/Manaus"}
-    assert to_string(dt) == "2000-02-29 23:00:07-02:30 Brazil/Manaus"
+    assert to_string(dt) == "2000-02-29 23:00:07-02:30 BRM Brazil/Manaus"
   end
 end