From 0640c6d963fbf368ed6309a8585802b45ecee146 Mon Sep 17 00:00:00 2001
From: Oliver Kriska <oliver@ideax.sk>
Date: Tue, 16 Jun 2026 10:25:41 +0200
Subject: [PATCH] Compute plural info once per PO file at compile time

`compile_po_file/5` derived the plural data twice: once in `nplurals/3` and
once in `compile_plural_forms/4`, each calling `Plural.plural_info/3`. That
function runs `Code.ensure_compiled!/1` and parses the `Plural-Forms` header,
so it is needless work repeated for every PO file across all locales and
domains.

Compute `plural_info` once in `compile_po_file/5` and pass it to both helpers.
The generated code is identical (the same value is escaped into the plural
dispatcher and fed to `nplurals/1`); only the duplicate computation is removed.
---
 CHANGELOG.md            |  1 +
 lib/gettext/compiler.ex | 16 +++++++---------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a82f28d..d6f5c94 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+  * Call `c:Gettext.Plural.init/1` once per PO file at compile time instead of twice.
   * Reduce the compile time of backends that use the default interpolation module by storing translations without interpolation in a literal map instead of generating one function clause each.
   * Add experimental `mix gettext.generate` task: messages are persisted as module attributes during normal compilation (for backends with `automatic_extraction: true` in the application environment, for example `config :gettext, MyApp.Gettext, automatic_extraction: true` in `config/dev.exs`) and read back from the compiled BEAM files, so extraction no longer needs to force-recompile the project.
 
diff --git a/lib/gettext/compiler.ex b/lib/gettext/compiler.ex
index 5a0575b..00db60d 100644
--- a/lib/gettext/compiler.ex
+++ b/lib/gettext/compiler.ex
@@ -498,8 +498,9 @@ defmodule Gettext.Compiler do
 
     plural_forms_fun = :"#{locale}_#{domain}_plural"
 
-    plural_forms = compile_plural_forms(locale, messages_struct, plural_mod, plural_forms_fun)
-    nplurals = nplurals(locale, messages_struct, plural_mod)
+    plural_info = Plural.plural_info(locale, messages_struct, plural_mod)
+    plural_forms = compile_plural_forms(plural_info, plural_mod, plural_forms_fun)
+    nplurals = nplurals(plural_info, plural_mod)
 
     singular_fun = :"#{locale}_#{domain}_lgettext"
     plural_fun = :"#{locale}_#{domain}_lngettext"
@@ -608,17 +609,14 @@ defmodule Gettext.Compiler do
     end
   end
 
-  defp nplurals(locale, messages_struct, plural_mod) do
-    plural_mod.nplurals(Plural.plural_info(locale, messages_struct, plural_mod))
+  defp nplurals(plural_info, plural_mod) do
+    plural_mod.nplurals(plural_info)
   end
 
-  defp compile_plural_forms(locale, messages_struct, plural_mod, plural_fun) do
+  defp compile_plural_forms(plural_info, plural_mod, plural_fun) do
     quote do
       defp unquote(plural_fun)(n) do
-        unquote(plural_mod).plural(
-          unquote(Macro.escape(Plural.plural_info(locale, messages_struct, plural_mod))),
-          n
-        )
+        unquote(plural_mod).plural(unquote(Macro.escape(plural_info)), n)
       end
     end
   end