Gettext for Elixir - getting serious at compile time

Transcript

1. gettext for elixir getting serious at compile time

2. None

3. processes otp supervision trees

4. vs compile time runtime

5. gettext is deadly simple at runtime

6. free } agent supervisor let it crash

7. andrea @whatyouhide leopardi

8. None

9. gettext

10. i18n b4g l10n internationalization localization boring

11. <%= translate "greetings.informal" %> # en_US.yml greetings: informal: "hello" context

    # en_TX.yml greetings: informal: "howdy" translation

12. # in en_TX/LC_MESSAGES/default.po #: lib/greetings.ex:24 msgid "hello" msgstr "howdy" <%=

    gettext "hello" %>

13. # in en_TX/LC_MESSAGES/default.po #: lib/greetings.ex:24 msgid "hello" msgstr "howdy" <%=

    gettext "hello" %>

14. # in en_TX/LC_MESSAGES/default.po #: lib/greetings.ex:24 msgid "hello" msgstr "howdy" <%=

    gettext "hello" %>

15. # in en_TX/LC_MESSAGES/default.po #: lib/greetings.ex:24 msgid "hello" msgstr "howdy" <%=

    gettext "hello" %>

16. # in en_TX/LC_MESSAGES/default.po #: lib/greetings.ex:24 msgid "hello" msgstr "howdy" <%=

    gettext "hello" %>

17. developers see plain strings

18. translators see plain strings

19. PO files

20. translator-friendly syntax # Enough with the greetings examples! #: lib/greeter.ex:24

    msgid "hello" msgstr "hola"

21. tools

22. gettext elixir-lang /

23. read translations from po files extract translations from source interpolate

    translations pluralization

24. read translations from PO files

25. defmodule Gettext do @translations Gettext.Compiler.po_files() for {msgid, msgstr} <- @translations

    do def gettext_fn(unquote(msgid)) do unquote(msgstr) end end end

26. defmodule Gettext do @translations Gettext.Compiler.po_files() for {msgid, msgstr} <- @translations

    do def gettext_fn(unquote(msgid)) do unquote(msgstr) end end end

27. defmodule Gettext do @translations Gettext.Compiler.po_files() for {msgid, msgstr} <- @translations

    do def gettext_fn(unquote(msgid)) do unquote(msgstr) end end end

28. defmodule Gettext do @translations Gettext.Compiler.po_files() for {msgid, msgstr} <- @translations

    do def gettext_fn(unquote(msgid)) do unquote(msgstr) end end end

29. defmodule Gettext do @translations Gettext.Compiler.po_files() for {msgid, msgstr} <- @translations

    do def gettext_fn(unquote(msgid)) do unquote(msgstr) end end end

30. defmodule Unicode do @pairs Unicode.read("data.txt") for {lower, upper} <- @pairs

    do def lower(unquote(upper)) do unquote(lower) end end end

31. very fast at runtime

32. move logic away from runtime

33. compiler friend is your the

34. extract translations from source

35. how they do it

36. printf(_("Hello"))

37. printf(_("Hello"))

38. how we do it

39. MACROS :D

40. functions that do stuff at compile time

41. mix gettext.extract calls mix compile --force

42. defmacro gettext(msgid) do extract(__CALLER__, msgid) quote do ... end end

43. defmacro gettext(msgid) do extract(__CALLER__, msgid) quote do ... end end

44. defmacro gettext(msgid) do extract(__CALLER__, msgid) quote do ... end end

    has to be a string

45. defmacro gettext(msgid) do extract(__CALLER__, msgid) quote do ... end end

    pushes to an agent

46. defmacro gettext(msgid) do extract(__CALLER__, msgid) quote do ... end end

    has context

47. actual implementation

48. zero runtime cost

49. compiler friend is your the

50. interpolate translations

51. gettext "Hello %{name}!", %{name: "Frodo"} case %{name: "Frodo"} do %{name:

    name} -> {:ok, "Hello " <> name} _ -> {:error, :bad_interp} end

52. gettext "Hello %{name}!", %{name: "Frodo"} case %{name: "Frodo"} do %{name:

    name} -> {:ok, "Hello " <> name} _ -> {:error, :bad_interp} end

53. easy pluralization support

54. import MyApp.Gettext ngettext "One attendant", "%{count} attendants", 254 msgid "One

    attendant" msgid_plural "%{count} attendants" msgstr[0] "Uno spettatore" msgstr[1] "%{count} spettatori"

55. # Arabic def plural("ar", 0), do: 0 def plural("ar", 1),

    do: 1 def plural("ar", 2), do: 2 def plural("ar", n) when rem(n, 100) >= 3 and ... def plural("ar", n) when rem(n, 100) >= 11, ... def plural("ar", _n), do: 5

56. workflow

57. define a gettext module defmodule MyApp.Gettext do use Gettext, otp_app:

    :my_app end

58. write source code import MyApp.Gettext gettext "Hello, world"

59. extract translations mix gettext.extract

60. extract translations POT files #: lib/greetings.ex:24 msgid "Hello, world!" msgstr

    ""

61. merge POT with locales mix gettext.merge priv/gettext --locale en_TX

62. merge POT with locales #: lib/old_greetings.ex:23 msgid "Hello, world!" msgstr

    "Ciao, mondo!"

63. merge POT with locales #: lib/greetings.ex:24 msgid "Hello, world!" msgstr

    "Ciao, mondo!"

64. merge POT with locales #: lib/greetings.ex:24 #, fuzzy msgid "Hello,

    world!" msgstr "Ciao, mondo"

65. Again

66. so.

67. github.com/elixir-lang/gettext

68. @WHATYOUHIDE