On Thu, 6 Oct 2016 21:18:15 -0400 Oren Watson <oren.wat...@gmail.com> wrote:
> On Thu, Oct 6, 2016 at 8:28 PM, Richard Wordingham < > richard.wording...@ntlworld.com> wrote: > > Yes, it's a trade-off. The application I had in mind is converting > > between mathematical letter variants and their 'plain' forms. > > Perhaps there is just enough information in the UCD to allow > > exhaustive, automated tests. > That application is hindered by the fact that > > ππππππΊπΏπ ππππππ π‘π£π€π§π¨ππΊπΌπ are unallocated > characters, forming gaps in the otherwise contiguous mathematical > alphabets. (Aside: That written statement is illegal! -:) Yep. It's a known nuisance, which is why I suggested exhaustive tests. My email client found a font to render U+1D547 as the unwary would expect, i.e. using a glyph suitable for β U+2119 DOUBLE-STRUCK CAPITAL P. I was surprised when I first saw those gaps; I would have expected characters with appropriate singleton decompositions to protect the unwary. (The idea might have come up at the time of encoding, and been dismissed with reasons.) I don't know whether the font's misrendering is an accident or is deliberate partial protection of the victims of bad character code selection. An old application of arithmetic was transliteration between the major Indian Indic scripts. That falls foul of Tamil and of characters that were not represented in ISCII. Richard.
