michaelkuc6/blog_os
1
0
Fork 0
mirror of https://github.com/phil-opp/blog_os.git synced 2025-12-16 22:37:49 +00:00
Code Issues Projects Releases Wiki Activity

Remove mention of byte strings as they are not compatible to write_str

Browse Source
This commit is contained in:
Philipp Oppermann
2016-02-04 16:41:58 +01:00
parent b092e79495
commit d421bac590
1 changed files with 1 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
posts/2015-10-23-printing-to-screen.md
View File

@@ -223,11 +223,10 @@ pub fn write_str(&mut self, s: &str) {
``` ```
You can try it yourself in the `print_something` function. You can try it yourself in the `print_something` function.
When you print strings with some special characters like `ä` or `λ`, you'll notice that they cause weird symbols on screen. That's because they are represented by multiple bytes in [UTF-8]. By converting them to bytes, we of course get strange results. But since the VGA buffer doesn't support UTF-8, it's not possible to display these characters anyway. To ensure that a string contains only ASCII characters, you can prefix a `b` to create a [Byte String]. When you print strings with some special characters like `ä` or `λ`, you'll notice that they cause weird symbols on screen. That's because they are represented by multiple bytes in [UTF-8]. By converting them to bytes, we of course get strange results. But since the VGA buffer doesn't support UTF-8, it's not possible to display these characters anyway.
[core tracking issue]: https://github.com/rust-lang/rust/issues/27701 [core tracking issue]: https://github.com/rust-lang/rust/issues/27701
[UTF-8]: http://www.fileformat.info/info/unicode/utf8.htm [UTF-8]: http://www.fileformat.info/info/unicode/utf8.htm
[Byte String]: https://doc.rust-lang.org/reference.html#characters-and-strings
### Support Formatting Macros ### Support Formatting Macros
It would be nice to support Rust's formatting macros, too. That way, we can easily print different types like integers or floats. To support them, we need to implement the [core::fmt::Write] trait. The only required method of this trait is `write_str` that looks quite similar to our `write_str` method. To implement the trait, we just need to move it into an `impl ::core::fmt::Write for Writer` block and add a return type: It would be nice to support Rust's formatting macros, too. That way, we can easily print different types like integers or floats. To support them, we need to implement the [core::fmt::Write] trait. The only required method of this trait is `write_str` that looks quite similar to our `write_str` method. To implement the trait, we just need to move it into an `impl ::core::fmt::Write for Writer` block and add a return type: