[i18n] Move to core:text/i18n.

core/text/i18n/i18n.odin

@@ -0,0 +1,170 @@
+package i18n
+/*
+	Internationalization helpers.
+
+	Copyright 2021-2022 Jeroen van Rijn <nom@duclavier.com>.
+	Made available under Odin's BSD-3 license.
+
+	List of contributors:
+		Jeroen van Rijn: Initial implementation.
+*/
+import "core:strings"
+
+/*
+	TODO:
+	- Support for more translation catalog file formats.
+*/
+
+/*
+	Currently active catalog.
+*/
+ACTIVE: ^Translation
+
+// Allow between 1 and 255 plural forms. Default: 10.
+MAX_PLURALS :: min(max(#config(ODIN_i18N_MAX_PLURAL_FORMS, 10), 1), 255)
+
+/*
+	The main data structure. This can be generated from various different file formats, as long as we have a parser for them.
+*/
+
+Section :: map[string][]string
+
+Translation :: struct {
+	k_v:    map[string]Section, // k_v[section][key][plural_form] = ...
+	intern: strings.Intern,
+
+	pluralize: proc(number: int) -> int,
+}
+
+Error :: enum {
+	/*
+		General return values.
+	*/
+	None = 0,
+	Empty_Translation_Catalog,
+	Duplicate_Key,
+
+	/*
+		Couldn't find, open or read file.
+	*/
+	File_Error,
+
+	/*
+		File too short.
+	*/
+	Premature_EOF,
+
+	/*
+		GNU Gettext *.MO file errors.
+	*/
+	MO_File_Invalid_Signature,
+	MO_File_Unsupported_Version,
+	MO_File_Invalid,
+	MO_File_Incorrect_Plural_Count,
+
+	/*
+		Qt Linguist *.TS file errors.
+	*/
+	TS_File_Parse_Error,
+	TS_File_Expected_Context,
+	TS_File_Expected_Context_Name,
+	TS_File_Expected_Source,
+	TS_File_Expected_Translation,
+	TS_File_Expected_NumerusForm,
+
+}
+
+/*
+	Several ways to use:
+	- get(key), which defaults to the singular form and i18n.ACTIVE catalog, or
+	- get(key, number), which returns the appropriate plural from the active catalog, or
+	- get(key, number, catalog) to grab text from a specific one.
+*/
+get_single_section :: proc(key: string, number := 0, catalog: ^Translation = ACTIVE) -> (value: string) {
+	/*
+		A lot of languages use singular for 1 item and plural for 0 or more than 1 items. This is our default pluralize rule.
+	*/
+	plural := 1 if number != 1 else 0
+
+	if catalog.pluralize != nil {
+		plural = catalog.pluralize(number)
+	}
+	return get_by_slot(key, plural, catalog)
+}
+
+/*
+	Several ways to use:
+	- get(section, key), which defaults to the singular form and i18n.ACTIVE catalog, or
+	- get(section, key, number), which returns the appropriate plural from the active catalog, or
+	- get(section, key, number, catalog) to grab text from a specific one.
+*/
+get_by_section :: proc(section, key: string, number := 0, catalog: ^Translation = ACTIVE) -> (value: string) {
+	/*
+		A lot of languages use singular for 1 item and plural for 0 or more than 1 items. This is our default pluralize rule.
+	*/
+	plural := 1 if number != 1 else 0
+
+	if catalog.pluralize != nil {
+		plural = catalog.pluralize(number)
+	}
+	return get_by_slot(section, key, plural, catalog)
+}
+get :: proc{get_single_section, get_by_section}
+
+/*
+	Several ways to use:
+	- get_by_slot(key), which defaults to the singular form and i18n.ACTIVE catalog, or
+	- get_by_slot(key, slot), which returns the requested plural from the active catalog, or
+	- get_by_slot(key, slot, catalog) to grab text from a specific one.
+
+	If a file format parser doesn't (yet) support plural slots, each of the slots will point at the same string.
+*/
+get_by_slot_single_section :: proc(key: string, slot := 0, catalog: ^Translation = ACTIVE) -> (value: string) {
+	return get_by_slot_by_section("", key, slot, catalog)
+}
+
+/*
+	Several ways to use:
+	- get_by_slot(key), which defaults to the singular form and i18n.ACTIVE catalog, or
+	- get_by_slot(key, slot), which returns the requested plural from the active catalog, or
+	- get_by_slot(key, slot, catalog) to grab text from a specific one.
+
+	If a file format parser doesn't (yet) support plural slots, each of the slots will point at the same string.
+*/
+get_by_slot_by_section :: proc(section, key: string, slot := 0, catalog: ^Translation = ACTIVE) -> (value: string) {
+	if catalog == nil || section not_in catalog.k_v {
+		/*
+			Return the key if the catalog catalog hasn't been initialized yet, or the section is not present.
+		*/
+		return key
+	}
+
+	/*
+		Return the translation from the requested slot if this key is known, else return the key.
+	*/
+	if translations, ok := catalog.k_v[section][key]; ok {
+		plural := min(max(0, slot), len(catalog.k_v[section][key]) - 1)
+		return translations[plural]
+	}
+	return key
+}
+get_by_slot :: proc{get_by_slot_single_section, get_by_slot_by_section}
+
+/*
+	Same for destroy:
+	- destroy(), to clean up the currently active catalog catalog i18n.ACTIVE
+	- destroy(catalog), to clean up a specific catalog.
+*/
+destroy :: proc(catalog: ^Translation = ACTIVE) {
+	if catalog != nil {
+		strings.intern_destroy(&catalog.intern)
+		for section in &catalog.k_v {
+			for key in &catalog.k_v[section] {
+				delete(catalog.k_v[section][key])
+			}
+			delete(catalog.k_v[section])
+		}
+		delete(catalog.k_v)
+		free(catalog)
+	}
+}