r12a
commented
4 years ago The first comment in this issue contains text that will automatically appear in the Bengali gap-analysis document as a subsection with the same title as this issue. Any edits made to that comment will be immediately available in the document. Proposals for changes or discussion of the content can be made in comments below this point.
Because of the problems associated with grapheme cluster boundaries (see above), first-letter selection in CSS doesn't work well for conjuncts. For example, chrome fails to style the whole conjunct in ব্রাউজার when using ::first-letter in a selector, and styles only the ব্ instead of ব্রা. Similar is the case of Internet Explorer, it only styles ব. This is problematic for many words in a script such as Bengali, and forces the content author to use explicit spans rather than the proper mechanism for selecting initial letter.
CSS uses the concept of 'typographic character unit', rather than grapheme cluster, in its specs with the explanation that these cases are beyond the scope of the grapheme cluster concept and that implementations should provide appropriate support. In addition, a modification to the concept of grapheme cluster is currently in development at the Unicode Consortium, which is likely to resolve the problem for a script like Bengali.
In addition, the alignment of styled initial-letter character glyphs with the rest of the text is not clearly specified or implemented.
See requirements at: Indic Layout Requirements