RE: Compression through normalization

[Arcane Jill]

I'm pretty sure it depends on whether you regard a text document as a 
sequence of characters, or as a sequence of glyphs. (Er - I mean 
"default grapheme clusters" of course). Regarded as a sequence of 
characters, normalisation changes that sequence. But regarded as a 
sequence of glyphs, normalisation leaves the sequence unchanged. So a 
compression algorithm could legitimately claim to be "lossless" if it 
did normalisation but operated at the glyph level.

I'm pretty sure you DON'T need to preserve the byte-stream bit for bit. 
For example, at the byte level, I see no reason to preserve invalid 
encoding sequences, and at the codepoint level I see no reason to 
preserve non-character codepoints. So - at the glyph level - we only 
need to preserve glyphs, no? It all depends on how the compression 
algorithm describes itself.

I think this might go wrong for "tailored grapheme clusters", but I 
don't know much about them.

Jill