Implement querying of localized values of desktop files

format/desktop_entry/desktop_entry.ha

@@ -1,58 +1,61 @@
+use locale;
+use strings;
+
 // Represents a file of the generic key/value format used by desktop entries.
 // Specification: §3
-type file = struct {
+export type file = struct {
-	preceeding_lines: []line;
+	preceeding_lines: []line,
-	groups:           []group;
+	groups:           []group,
 };
 
 // A named group of key/value entries.
 // Specification: §3.2
-type group = struct {
+export type group = struct {
-	name:  str;
+	name:  str,
-	lines: []line;
+	lines: []line,
-}
+};
 
 // A line in the file, which can be a comment (or a blank line), an entry, or
 // a localized entry.
-type line = (comment | entry | localized_entry);
+export type line = (comment | entry | localized_entry);
 
 // A comment.
 // Specification: §3.1
-type comment = str;
+export type comment = str;
 
 // A key/value pair.
 // Specification: §3.3
-type entry = struct {
+export type entry = struct {
-	key:   str;
+	key:   str,
-	value: value;
+	value: value,
 };
 
 // A localized entry.
 // Specification: §5
-type localized_entry struct {
+export type localized_entry = struct {
-	key:    str;
+	key:    str,
-	value:  value;
+	value:  value,
-	locale: locale::locale;
+	locale: locale::locale,
 };
 
 // An entry value. Values that reference memory (such as [[str]]) are borrowed
 // from the [[file]]. These may be free'd or overwritten when other functions in
 // this module are called, so [[value_dup]] is required to extend its lifetime.
-export type value = (str, bool, f32);
+export type value = (str | bool | f32);
 
 // Gets a non-localized value from a file. If the group does not exist, or the
 // group exists but the key isn't in it, it returns void.
-export fn file_get(fil: *file, group_name: str, key: str) (value | void) {
+export fn file_get(fil: *file, group_name: str, key: str) (value | void) = {
 	let grou = match (file_find_group(fil, group_name)) {
-	case index: size => yield &file.groups[index];
+	case let index: size => yield &fil.groups[index];
 	case void            => return void;
 	};
 	let lin = match (group_find_entry(grou, key)) {
-	case index: size => yield &grou.lines[index];
+	case let index: size => yield grou.lines[index];
 	case void            => return void;
 	};
 	match (lin) {
-	case entr: entry => return entr.value;
+	case let entr: entry => return entr.value;
 	case                 => abort();
 	};
 };
@@ -65,67 +68,131 @@ export fn file_get_localized(
 	fil:        *file,
 	group_name: str,
 	key:        str,
-	local:      locale,
+	local:      locale::locale,
-) (value | void) {
+) (value | void) = {
 	let grou = match (file_find_group(fil, group_name)) {
-	case index: size => yield &file.groups[index];
+	case let index: size => yield &fil.groups[index];
 	case void            => return void;
 	};
 	let lin = match (group_find_localized_entry(grou, key, local)) {
-	case index: size => yield &grou.lines[index];
+	case let index: size => yield grou.lines[index];
+	case void =>
+		yield match(group_find_entry(grou, key)) {
+		case let index: size => yield index;
 		case void            => return void;
 		};
+	};
 	match (lin) {
-	case entr: localized_entry => return entr.value;
+	case let entr: localized_entry => return entr.value;
-	case entr: entry           => return entr.value;
+	case let entr: entry           => return entr.value;
 	case                           => abort();
 	};
 };
 
-export fn file_add
+//export fn file_add
 
-export fn file_add_localized
+//export fn file_add_localized
 
-export fn file_remove
+//export fn file_remove
 
-export fn file_remove_localized
+//export fn file_remove_localized
 
-export fn file_encode
+//export fn file_encode
 
-export fn file_finish
+//export fn file_finish
 
-fn file_find_group (fil *file, group_name str): (size | void) = {
+fn file_find_group(fil: *file, group_name: str) (size | void) = {
-	let index = 0;
+	let index = 0z;
-	for (let grou .. file.groups) {
+	for (let grou .. fil.groups) {
-		if (strings::compare(group.name, group_name) == 0) {
+		if (grou.name == group_name) {
 			return index;
-		}
+		};
-		index ++;
+		index += 1;
-	}
+	};
-}
+};
 
-fn group_find_entry (grou *group, key str): (size | void) {
+fn group_find_entry(grou: *group, key: str) (size | void) = {
-	let index = 0;
+	let index = 0z;
 	for (let lin .. grou.lines) {
 		match (lin) {
-		case entr: entry =>
+		case let entr: entry =>
-			if (strings::compare(entry.key, entr) == 0) {
+			if (entr.key == key) {
 				return index;
-			}
+			};
-		case => void ;
+		case => void;
-		}
+		};
-		index ++;
+		index += 1;
-	}
+	};
-}
+};
+
+fn group_find_localized_entry(grou: *group, key: str, local: locale::locale) (size | 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.
+
+	let lang_country_modifier = local;
+	lang_country_modifier.encoding = "";
+	match(group_find_localized_entry_exact(grou, key, lang_country_modifier)) {
+	case let index: size => return index;
+	case                 =>	void;
+	};
+	
+	let lang_country = lang_country_modifier;
+	lang_country.modifier = "";
+	match(group_find_localized_entry_exact(grou, key, lang_country)) {
+	case let index: size => return index;
+	case                 =>	void;
+	};
+	
+	let lang_modifier = lang_country_modifier;
+	lang_modifier.country = "";
+	match(group_find_localized_entry_exact(grou, key, lang_modifier)) {
+	case let index: size => return index;
+	case                 =>	void;
+	};
+
+	let lang = lang_modifier;
+	lang.modifier = "";
+	match(group_find_localized_entry_exact(grou, key, lang)) {
+	case let index: size => return index;
+	case                 =>	void;
+	};
+	
+	return void;
+};
+
+fn group_find_localized_entry_exact(grou: *group, key: str, local: locale::locale) (size | void) = {
+	let index = 0z;
+	for (let lin .. grou.lines) {
+		match (lin) {
+		case let entr: localized_entry =>
+			if (entr.key == key && locale::equal(entr.locale, local)) {
+				return index;
+			};
+		case => void;
+		};
+		index += 1;
+	};
+};
 
 // Duplicates a [[value]]. Use [[value_finish]] to get rid of it.
-export fn value_dup(valu: value): value = match (valu) {
+export fn value_dup(valu: value) value = match (valu) {
-case let valu: str => yield strings.dup(valu);
+case let valu: str => yield strings::dup(valu);
 case               => yield valu;
 };
 
 // Frees an [[entry]] previously duplicated with [[entry_dup]].
-export fn value_finish(valu: value): void = match (valu) {
+export fn value_finish(valu: value) void = match (valu) {
 case let valu: str => free(valu);
 case               => void;
 };