add ghostty_translate C API

src/build/GhosttyI18n.zig

@@ -3,13 +3,10 @@ const GhosttyI18n = @This();
 const std = @import("std");
 const Config = @import("Config.zig");
 const gresource = @import("../apprt/gtk/gresource.zig");
+const internal_os = @import("../os/main.zig");
 
 const domain = "com.mitchellh.ghostty";
 
-const locales = [_][]const u8{
-    "zh_CN.UTF-8",
-};
-
 owner: *std.Build,
 steps: []*std.Build.Step,
 
@@ -23,7 +20,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyI18n {
     var steps = std.ArrayList(*std.Build.Step).init(b.allocator);
     defer steps.deinit();
 
-    inline for (locales) |locale| {
+    inline for (internal_os.i18n.locales) |locale| {
         const msgfmt = b.addSystemCommand(&.{ "msgfmt", "-o", "-" });
         msgfmt.addFileArg(b.path("po/" ++ locale ++ ".po"));
 
@@ -106,7 +103,7 @@ fn createUpdateStep(b: *std.Build) !*std.Build.Step {
         "po/" ++ domain ++ ".pot",
     );
 
-    inline for (locales) |locale| {
+    inline for (internal_os.i18n.locales) |locale| {
         const msgmerge = b.addSystemCommand(&.{ "msgmerge", "-q" });
         msgmerge.addFileArg(b.path("po/" ++ locale ++ ".po"));
         msgmerge.addFileArg(xgettext.captureStdOut());

src/main_c.zig

@@ -15,6 +15,7 @@ const build_config = @import("build_config.zig");
 const main = @import("main_ghostty.zig");
 const state = &@import("global.zig").state;
 const apprt = @import("apprt.zig");
+const internal_os = @import("os/main.zig");
 
 // Some comptime assertions that our C API depends on.
 comptime {
@@ -88,3 +89,13 @@ export fn ghostty_info() Info {
         .version_len = build_config.version_string.len,
     };
 }
+
+/// Translate a string maintained by libghostty into the current
+/// application language. This will return the same string (same pointer)
+/// if no translation is found, so the pointer must be stable through
+/// the function call.
+///
+/// This should only be used for singular strings maintained by Ghostty.
+export fn ghostty_translate(msgid: [*:0]const u8) [*:0]const u8 {
+    return internal_os.i18n._(msgid);
+}

src/os/i18n.zig

@@ -3,6 +3,13 @@ const build_config = @import("../build_config.zig");
 
 const log = std.log.scoped(.i18n);
 
+/// Supported locales for the application. This must be kept up to date
+/// with the translations available in the `po/` directory; this is used
+/// by our build process as well runtime libghostty APIs.
+pub const locales = [_][]const u8{
+    "zh_CN.UTF-8",
+};
+
 pub const InitError = error{
     InvalidResourcesDir,
     OutOfMemory,