langrustang

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Multilingual Support for Rust Program

Multilingual support is possible based on yaml.

(Not distributed on crates.io)

(Mostly for my own use) If you want to use this crate,

add the following to the dependencies in your Cargo.toml:

# Please change the tag version accordingly.
langrustang = { git = "https://github.com/aq2r/langrustang", tag = "v1.1.4" }

How to write yaml

The yaml file is written in the following format:

Any_key:
  all:
  any_lang_key_1: XXX
  any_lang_key_2: YYY
  any_lang_key_3: ZZZ

Any_key2:
  ...

Any_key can contain any characters.

The first character of any_lang_key must be a lowercase alphabet,

and the second and subsequent characters must be lowercase alphabets, numbers, or underscores.

And the last character of the language key cannot be an underscore.

Examples

lang.yaml:

lang_t_ex1:
  all: ALL_EXAMPLE

lang_t_ex2:
  ja: おはよう
  en: hello!
  zh: 你好
  anykey1: Any?
  some_key_2: Some!

lang_t_ex3:
  all: ALL

  ja: おはよう
  en: hello!
  zh: 你好

lang_t_ex4:
  ja: おはよう
  en: hello!
  zh: 你好

format_t_ex1:
  all: "Hi, {}! "

format_t_ex2:
  all: "{}, ALL!"
  ja: "{}, おはよう!"
  en: "{}, Hello!"
  zh: "{}, 你好!"

main.rs:

langrustang::i18n!("lang.yaml");  // Auto-generate `_langrustang_autogen::Lang`
use crate::_langrustang_autogen::Lang;

use langrustang::{lang_t, println_t};

fn main() {
    // The enum elements are automatically generated based on the yaml keys.
    let lang_en = Lang::En;
    let lang_ja = Lang::Ja;
    let lang_zh = Lang::Zh;
    let lang_anykey1 = Lang::Anykey1;
    let lang_somekey2 = Lang::SomeKey2;

    println!("{}", lang_t!("lang_t_ex1")); // ALL_EXAMPLE

    println!("{}", lang_t!("lang_t_ex2", lang_en)); // hello!
    println!("{}", lang_t!("lang_t_ex2", lang_ja)); // おはよう
    println!("{}", lang_t!("lang_t_ex2", lang_zh)); // 你好

    println!("{}", lang_t!("lang_t_ex3", lang_en)); // hello!
    println!("{}", lang_t!("lang_t_ex3", lang_anykey1)); // ALL

    // println!("{}", lang_t!("lang_t_ex4", lang_anykey1)); // Missing language key: ["any_key1", "some_key_2"]

    let name = "Ferris";
    println_t!("format_t_ex1", name);
    println_t!("format_t_ex2", lang_ja, name);
}

lang_t!

• Example 1

If the language key is just 'all', then it will be retrieved using only the key.

println!("{}", lang_t!("lang_t_ex1")); // ALL_EXAMPLE

• Example 2

If there are other keys present besides all,

we use the auto-generated Lang Enum to extract them.

println!("{}", lang_t!("lang_t_ex2", lang_en)); // hello!
println!("{}", lang_t!("lang_t_ex2", lang_ja)); // おはよう
println!("{}", lang_t!("lang_t_ex2", lang_zh)); // 你好

• Example 3

If a language key is missing, specifying key will result in a compilation error.

However, if the all key is specified, that value will be used instead.

println!("{}", lang_t!("lang_t_ex3", lang_en)); // hello!
println!("{}", lang_t!("lang_t_ex3", lang_anykey1)); // ALL

// println!("{}", lang_t!("lang_t_ex4", lang_en)); // Compile Error!

format_t!, print_t!, println_t!

If you only have the all key, pass the YAML key first and

the formatting arguments from the second onwards, just like a normal format.

If a language key is specified, pass the yaml key as the first argument,

the Lang Enum as the second argument, and then the thing you want to format.

let name = "Ferris";

println_t!("format_t_ex1", name); // Hi, Ferris!
println_t!("format_t_ex2", lang_ja, name); // Ferris, おはよう!