Setup SILE interface to be localized

.commitlintrc.yml

@@ -38,6 +38,7 @@ rules:
     - inputs
     - installation
     - languages
+    - l10n
     - manpage
     - manual
     - math

core/languages.lua

@@ -3,7 +3,7 @@ local loadkit = require("loadkit")
 loadkit.register("ftl", function (file)
   local contents = assert(file:read("*a"))
   file:close()
-  return assert(SILE.fluent:add_messages(contents))
+  return contents
 end)
 
 SILE.languageSupport = {
@@ -13,25 +13,43 @@ SILE.languageSupport = {
     language = SILE.cldr.locales[language] and language or "und"
     if SILE.languageSupport.languages[language] then return end
     if SILE.hyphenator.languages[language] then return end
-    local lang, fail = pcall(function () SILE.require("languages/" .. language) end)
-    if fail then
-      if fail:match("not found") then fail = "no support for this language" end
-      SU.warn("Error loading language " .. language .. ": " .. fail)
+    local ret1, lang = pcall(SILE.require, "languages/" .. language)
+    if not ret1 then
+      if lang:match("not found") then lang = "no support for this language" end
+      SU.warn("Error loading language " .. language .. ": " .. lang)
       SILE.languageSupport.languages[language] = {} -- Don't try again
     end
     local ftlresource = string.format("i18n.%s", language)
     SU.debug("fluent", "Loading FTL resource", ftlresource, "into locale", language)
     SILE.fluent:set_locale(language)
-    local _, ftlfail = pcall(function () return require(ftlresource) end)
-    if not ftlfail then
-      SU.warn("Error loading localizations " .. language .. ": " .. ftlfail)
+    local ret2, ftl = pcall(require, ftlresource)
+    if ret2 then
+      SILE.fluent:add_messages(ftl)
+    else
+      SU.warn("No document localizations found for " .. language .. ": " .. ftl)
     end
     if type(lang) == "table" and lang.init then
       lang.init()
     end
   end
 }
 
+-- Function to load UI localizations for SILE itself. Also sets the default
+-- document language, but this is primarily about the UI not the document.
+SILE.set_locale = function (locale)
+  locale = SILE.cldr.locales[locale] and locale or "en"
+  SILE.languageSupport.loadLanguage(locale)
+  SILE.settings.set("document.language", locale, true)
+  SILE.l10n:set_locale(locale)
+  local ftlresource = string.format("l10n.%s", locale)
+  local ret, ftl = pcall(require, ftlresource)
+  if ret then
+    SILE.l10n:add_messages(ftl)
+  else
+    SU.warn("Error loading UI localizations " .. locale .. ": " .. ftl)
+  end
+end
+
 SILE.registerCommand("language", function (options, content)
   local main = SU.required(options, "main", "language setting")
   SILE.languageSupport.loadLanguage(main)

core/measurement.lua

@@ -84,6 +84,7 @@ local measurement = pl.class({
     end,
 
     __tostring = function (self)
+      SU.debug("l10n", "measurement to string")
       return self.amount .. self.unit
     end,
 

core/sile.lua

@@ -38,7 +38,8 @@ SILE.preamble = {}
 
 -- Internal functions / classes / factories
 SILE.cldr = require("cldr")
-SILE.fluent = require("fluent")()
+SILE.fluent = require("fluent")() -- for document localizations
+SILE.l10n = require("fluent")() -- for UI localizations
 SILE.utilities = require("core/utilities")
 SU = SILE.utilities -- alias
 SILE.traceStack = require("core/tracestack")()
@@ -127,6 +128,7 @@ SILE.parseArguments = function ()
   cli:splat("INPUT", "input file, SIL or XML format")
   cli:option("-b, --backend=VALUE", "choose an alternative output backend")
   cli:option("-d, --debug=VALUE", "show debug information for tagged aspects of SILE’s operation", {})
+  cli:option("-l, --locale=VALUE", "locale for SILE interface and default document language", {})
   cli:option("-e, --evaluate=VALUE", "evaluate some Lua code before processing file", {})
   cli:option("-f, --fontmanager=VALUE", "choose an alternative font manager")
   cli:option("-m, --makedeps=FILE", "generate a list of dependencies in Makefile format")
@@ -153,6 +155,11 @@ SILE.parseArguments = function ()
     SILE.masterFilename = string.match(SILE.inputFile, "(.+)%..-$") or SILE.inputFile
     SILE.masterDir = SILE.masterFilename:match("(.-)[^%/]+$")
   end
+  if opts.locale then
+    for _, locale in ipairs(opts.locale) do
+      SILE.set_locale(locale)
+    end
+  end
   if opts.backend then
     SILE.backend = opts.backend
   end

core/utilities.lua

@@ -43,6 +43,25 @@ utilities.warn = function(message, bug)
   io.stderr:write("\n")
 end
 
+utilities.info = function(message, ...)
+  SU.msg(message, ...)
+end
+
+utilities.msg = function(message, ...)
+  local inputs = pl.utils.pack(...)
+  for i, v in ipairs(inputs) do
+    inputs[i] = nil
+    inputs[string.char(96+i)] = tostring(v)
+  end
+  local msg = SILE.l10n[message](inputs)
+  SU.debug("l10n", msg)
+  -- SU.dump{ message, callback }
+  -- local arg = { ... } -- Avoid things that Lua stuffs in arg like args to self()
+  -- pl.pretty.dump(#arg == 1 and arg[1] or arg, "/dev/stderr")
+    -- local inputs = table.pack(...)
+    -- for i, input in ipairs(inputs) do
+end
+
 utilities.debugging = function (category)
   return SILE.debugFlags.all or SILE.debugFlags[category]
 end

l10n/en.ftl

@@ -0,0 +1,3 @@
+full-version = SILE { $a }
+
+loading = Loading { $a }

sile.1.in

@@ -22,6 +22,10 @@ Print help message and exit.
 .BR \-v ", " \-\-version
 Print version information and exit.
 .TP
+.BR \-l ", " \-\-locale= \fIvalue\fR
+Interface locale for localized messages.
+Also sets the default document language.
+.TP
 .BR \-b ", " \-\-backend= \fIvalue\fR
 Choose an alternative output backend.
 The default backend for producing PDF files is \fIlibtexpdf\fR.

sile.in

@@ -36,6 +36,12 @@ extendPath(".")
 SILE = require("core/sile")
 SILE.version = "v@VERSION@"
 io.stdout:setvbuf 'no'
+
+-- Load at least a default locale, may be overridden shortly when we parse arguments
+-- but we will always want to be able to fall back to these localizations for any
+-- messages that are not localized anyway so this is not a waste.
+SILE.set_locale("en")
+
 SILE.parseArguments()
 if not os.getenv 'LUA_REPL_RLWRAP' then
   io.stderr:write(SILE.full_version .. '\n')