locale: Add support for localized string list

locale/string.ha

@@ -1,26 +1,27 @@
 // A string localized into multiple locales.
 export type string = [](locale, str);
 
+// -------------------------------------------------------------------------- //
+// The matching is done as follows. If LC_MESSAGES is of the form
+// lang_COUNTRY.ENCODING@MODIFIER, then it will match a key of the form
+// lang_COUNTRY@MODIFIER. If such a key does not exist, it will attempt to match
+// lang_COUNTRY followed by lang@MODIFIER. Then, a match against lang by itself
+// will be attempted. Finally, if no matching key is found the required key
+// without a locale specified is used. The encoding from the LC_MESSAGES value
+// is ignored when matching.
+// 
+// If LC_MESSAGES does not have a MODIFIER field, then no key with a modifier
+// will be matched. Similarly, if LC_MESSAGES does not have a COUNTRY field,
+// then no key with a country specified will be matched. If LC_MESSAGES just has
+// a lang field, then it will do a straight match to a key with a similar value.
+// -------------------------------------------------------------------------- //
+
 // Selects the most appropriate localized version of a [[string]] given a
 // [[locale]]. The matching algorithm used is the one specified by the
 // XDG Desktop Entry Specification, §5. If no suitable version is found, an
 // exact match with the C locale will be attempted. If there are none, void will
 // be returned. Memory is borrowed from the input.
-export fn string_resolve(strin: string, local: locale) (str | void) = {
+export fn string_resolve(strin: string, local: locale) (str | void) = {	
-	// The matching is done as follows. If LC_MESSAGES is of the form
-	// lang_COUNTRY.ENCODING@MODIFIER, then it will match a key of the form
-	// lang_COUNTRY@MODIFIER. If such a key does not exist, it will attempt
-	// to match lang_COUNTRY followed by lang@MODIFIER. Then, a match
-	// against lang by itself will be attempted. Finally, if no matching key
-	// is found the required key without a locale specified is used. The
-	// encoding from the LC_MESSAGES value is ignored when matching.
-	// 
-	// If LC_MESSAGES does not have a MODIFIER field, then no key with a
-	// modifier will be matched. Similarly, if LC_MESSAGES does not have a
-	// COUNTRY field, then no key with a country specified will be matched.
-	// If LC_MESSAGES just has a lang field, then it will do a straight
-	// match to a key with a similar value.
-	
 	// lang_COUNTRY@MODIFIER
 	let lang_country_modifier = local;
 	lang_country_modifier.encoding = "";
@@ -65,3 +66,55 @@ export fn string_resolve(strin: string, local: locale) (str | void) = {
 fn string_resolve_exact(strin: string, local: locale) (str | void) = {
 	for (let pair .. strin) if(equal(pair.0, local)) return pair.1;
 };
+
+// A list of strings localized into multiple locales.
+export type strings = [](locale, []str);
+
+// Selects the most appropriate localized version of a [[string]] given a
+// [[locale]]. See the documentation for [[string_resolve]] for more
+// information.
+export fn strings_resolve(strins: strings, local: locale) ([]str | void) = {
+	// lang_COUNTRY@MODIFIER
+	let lang_country_modifier = local;
+	lang_country_modifier.encoding = "";
+	match (strings_resolve_exact(strins, lang_country_modifier)) {
+	case let result: []str => return result;
+	case                   => void;
+	};
+	
+	// lang_COUNTRY
+	let lang_country = local;
+	lang_country.modifier = "";
+	match (strings_resolve_exact(strins, lang_country)) {
+	case let result: []str => return result;
+	case                   => void;
+	};
+	
+	// lang@MODIFIER
+	let lang_modifier = lang_country_modifier;
+	lang_modifier.country = "";
+	match (strings_resolve_exact(strins, lang_modifier)) {
+	case let result: []str => return result;
+	case                   => void;
+	};
+
+	// lang
+	let lang = lang_modifier;
+	lang.modifier = "";
+	match (strings_resolve_exact(strins, lang)) {
+	case let result: []str => return result;
+	case                   => void;
+	};
+
+	// fallback to c locale
+	match (strings_resolve_exact(strins, c)) {
+	case let result: []str => return result;
+	case                   => void;
+	};
+	
+	return void;
+};
+
+fn strings_resolve_exact(strins: strings, local: locale) ([]str | void) = {
+	for (let pair .. strins) if(equal(pair.0, local)) return pair.1;
+};