grapheme_iter.rs

    #[test]
    fn grapheme_iter() {
        let text = "a👩‍🔬";
        let mut c = unicode_segmentation::GraphemeCursor::new(text.len(), text.len(), true);
        dbg!(text.len());
        dbg!(text.char_indices().map(|(i, c)| (i, c)).collect::<Vec<_>>());
        assert_eq!(
            c.prev_boundary(&text[(text.len() - 4)..], text.len() - 4),
            Err(GraphemeIncomplete::PrevChunk)
        );
        assert_eq!(
            c.prev_boundary(&text[(text.len() - (4 + 3))..], text.len() - (4 + 3)),
            Err(GraphemeIncomplete::PreContext(5))
        );
        c.provide_context(&text[0..5], 0);
        assert_eq!(
            c.prev_boundary(&text[(text.len() - (4 + 3))..], text.len() - (4 + 3)),
            Ok(Some(8))
        );
    }