Grapheme clusters fail to represent syllabic conjuncts in Tamil

[r12a]

The Unicode concept of 'grapheme cluster' currently fails to represent the small number of conjuncts that are used in modern Tamil, ie. kṣa க்ஷ and the two alternative sequences for srī, ஶ்ரீ and ஸ்ரீ. This means that various editing operations, line breaking algorithms, vertical text, etc. are liable to break text at the wrong point when those conjuncts are used. For more details, see the relevant sections.

Indic Layout Requirements provides a grammar for indian orthographic syllable boundaries which works for the consonant clusters in Tamil which don't use conjuncts.

Specs:
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.

[r12a]

The first comment in this issue contains text that will automatically appear in the Tamil 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.

[miloush]

Does this refer to ஸ்ரீ and க்ஷ only?

[r12a]

Well, those two and ஶ்ரீ also (the Unicode recommended sequence for shri). The text in this section was very old and i made some badly needed edits. (See the 'edited' pulldown for the initial comment.)