[iip] Grapheme clusters fail to represent syllabic conjuncts (#72)

r12a has just created a new issue for https://github.com/w3c/iip:

== Grapheme clusters fail to represent syllabic conjuncts ==
The Unicode concept of 'grapheme cluster' currently fails to represent ligatures and conjuncts in scripts like Tamil. This means that various editing operations, line breaking algorithms, vertical text, etc. are likely to break text at the wrong point.

<a href="https://w3c.github.io/ilreq/#h_indic_orthographic_syllable_boundaries">Indic Layout Requirements</a> provides a grammar for indian orthographic syllable boundaries which works for Tamil, and CSS uses the concept of <a href="https://drafts.csswg.org/css-text-3/#typographic-character-unit">'typographic character unit'</a>, 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 <a href="https://www.unicode.org/reports/tr29/proposed.html#Rule_Constraints">currently in development</a> at the Unicode Consortium, which is likely to resolve the problem for a script like Tamil.

See requirements at: <a href="https://w3c.github.io/ilreq/#h_indic_orthographic_syllable_boundaries">Indic Layout Requirements</a>

Please view or discuss this issue at https://github.com/w3c/iip/issues/72 using your GitHub account

Received on Tuesday, 4 February 2020 18:21:58 UTC