Gettext for Elixir - getting serious at compile time

Transcript

1. gettext for elixir getting serious at compile time
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
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