Expand description

This module exposes tooling for running the unicode bidi algorithm using ICU4X data.

BidiClassAdapter enables ICU4X to provide data to [unicode-bidi], an external crate implementing UAX #9.


 use icu_properties::bidi::BidiClassAdapter;
 use icu_properties::maps;
 use unicode_bidi::BidiInfo;
 // This example text is defined using `concat!` because some browsers
 // and text editors have trouble displaying bidi strings.
 let text =  concat!["א", // RTL#1
                     "ב", // RTL#2
                     "ג", // RTL#3
                     "a", // LTR#1
                     "b", // LTR#2
                     "c", // LTR#3
                     ]; //

 let data = maps::load_bidi_class(&icu_testdata::unstable()).expect("The data should be valid");
 let bc = data.as_borrowed();

 let adapter = BidiClassAdapter::new(bc);
 // Resolve embedding levels within the text.  Pass `None` to detect the
 // paragraph level automatically.

 let bidi_info = BidiInfo::new_with_data_source(&adapter, text, None);

 // This paragraph has embedding level 1 because its first strong character is RTL.
 assert_eq!(bidi_info.paragraphs.len(), 1);
 let para = &bidi_info.paragraphs[0];
 assert_eq!(para.level.number(), 1);

 // Re-ordering is done after wrapping each paragraph into a sequence of
 // lines. For this example, I'll just use a single line that spans the
 // entire paragraph.
 let line = para.range.clone();

 let display = bidi_info.reorder_line(para, line);
 assert_eq!(display, concat!["a", // LTR#1
                             "b", // LTR#2
                             "c", // LTR#3
                             "ג", // RTL#3
                             "ב", // RTL#2
                             "א", // RTL#1


An adapter to convert from icu4x BidiClass to unicode_bidi::BidiClass.