Yore

A Rust library for decoding and encoding character sets based on OEM code pages.

Features

• Fast performance*
• Minimal memory usage with Cow and shrink_to_fit
• Easy-to-use API
• Broad range of supported code pages
• Handles code pages with redefined ASCII characters (<0x80), such as '٪' in CP864
• no_std support, with or without an allocator — down to allocation-free encode_char / decode_byte primitives for embedded use

Usage

Add yore to your Cargo.toml file.

[dependencies]
yore = "2.1.1"

Examples

Using a specific code page

use yore::code_pages::{CP857,CP850};use yore::{DecodeError,EncodeError};// Vec contains ASCII "text"let bytes = vec![116,101,120,116];// Vec contains ASCII "text " and codepoint 231let bytes_undefined = vec![116,101,120,116,32,231];// Notice that decoding CP850 can't fail because it is completely definedassert_eq!(CP850.decode(&bytes),"text");// However, CP857 can failassert_eq!(CP857.decode(&bytes).unwrap(),"text");// "text " + codepoint 231 assert!(matches!(CP857.decode(&bytes_undefined),DecodeError));// Lossy decoding won't fail due to fallbackassert_eq!(CP857.decode_lossy(&bytes_undefined),"text �");// Encodingassert_eq!(CP850.encode("text").unwrap(), bytes);assert!(matches!(CP850.encode("text 🦀"),EncodeError));assert_eq!(CP850.encode_lossy("text 🦀",231), bytes_undefined);

Using a trait object

use yore::CodePage;fndo_something(code_page:&dynCodePage,bytes:&[u8]){println!("{}", code_page.decode(bytes).unwrap());}

Supported code pages

Identifier	Name	Description
437	ibm437	OEM United States
737	ibm737	OEM Greek (formerly 437G); Greek (DOS)
775	ibm775	OEM Baltic; Baltic (DOS)
850	ibm850	OEM Multilingual Latin 1; Western European (DOS)
852	ibm852	OEM Latin 2; Central European (DOS)
855	ibm855	OEM Cyrillic (primarily Russian)
857	ibm857	OEM Turkish; Turkish (DOS)
860	ibm860	OEM Portuguese; Portuguese (DOS)
861	ibm861	OEM Icelandic; Icelandic (DOS)
862	dos-862	OEM Hebrew; Hebrew (DOS)
863	ibm863	OEM French Canadian; French Canadian (DOS)
864	ibm864	OEM Arabic; Arabic (864)
865	ibm865	OEM Nordic; Nordic (DOS)
866	cp866	OEM Russian; Cyrillic (DOS)
869	ibm869	OEM Modern Greek; Greek, Modern (DOS)
874	windows-874	Thai (Windows)
910	ibm910	IBM-PC APL2
1250	windows-1250	ANSI Central European; Central European (Windows)
1251	windows-1251	ANSI Cyrillic; Cyrillic (Windows)
1252	windows-1252	ANSI Latin 1; Western European (Windows)
1253	windows-1253	ANSI Greek; Greek (Windows)
1254	windows-1254	ANSI Turkish; Turkish (Windows)
1255	windows-1255	ANSI Hebrew; Hebrew (Windows)
1256	windows-1256	ANSI Arabic; Arabic (Windows)
1257	windows-1257	ANSI Baltic; Baltic (Windows)
1258	windows-1258	ANSI/OEM Vietnamese; Vietnamese (Windows)

* Benchmarks

encoding_rs supports only a few of the encodings that oem_cp and yore support. Additionally, encoding_rs focuses on streaming use cases.

Refer to the bench crate for more details.

no_std

yore has three feature tiers, so it scales from std down to bare-metal targets with no allocator:

Cargo features	Environment	API
std (default)	std	Full API + std::error::Error impls
alloc	no_std + allocator	Full API; Error impls omitted (Display stays)
(none)	no_std, no allocator	Allocation-free char primitives only

The allocating encode/decode family returns owned Cow buffers and so requires the alloc feature. Without it, only the allocation-free encode_char / decode_byte primitives are available:

[dependencies]
# no_std with an allocator: keep the full Cow-returning APIyore = { version = "2.1.1", default-features = false, features = ["alloc"] }
# no_std without an allocator: char primitives onlyyore = { version = "2.1.1", default-features = false }

use yore::code_pages::CP850;// Encode/decode one character at a time, no allocation required.assert_eq!(CP850.encode_char('A'),Some(b'A'));assert_eq!(CP850.decode_byte(b'A'),'A');

CP437G (VGA text-mode glyphs)

The optional cp437g feature adds the CP437G code page: CP437 overlaid with the IBM-Graphics glyphs (☺ ♥ ♪ → ⌂ ...) at the C0 control byte range, as the VGA BIOS glyph ROM renders them. It pairs well with encode_char for driving a text buffer from a no_std kernel.

[dependencies]
yore = { version = "2.1.1", features = ["cp437g"] }

use yore::code_pages::CP437G;assert_eq!(CP437G.encode_char('☺'),Some(0x01));assert_eq!(CP437G.decode_byte(0x01),'☺');

Some glyphs share a byte with an ASCII control character (0x09 ○, 0x0A ◙, 0x0D ♪). The ASCII fast-path still encodes '\t'/'\n'/'\r' to those bytes, so intercept the source char first if you need newline semantics.

Contributing

See CONTRIBUTING.md for development setup, benchmarking, and fuzzing.