On: Picking Apart the Crashing iOS String

[donarb]

Very interesting article. It gives a bit more perspective to the problem than the simplistic view that iOS has a problem displaying a certain character onscreen.

This particular bug shows the problem with multibyte characters (terminology may be wrong, perhaps multi glyph is better) where certain parts of the character become left or right associative based on context.

[Manishearth → donarb]

You want "multi-codepoint graphemes" probably. Or really "things involving combining characters". There isn't really a term for this.

[bitwize → Manishearth]

I believe the Unicode term is "grapheme cluster".

[Manishearth → bitwize]

Not exactly, no.

क्र is currently not a grapheme cluster, for example (there is a proposed change to UAX 29 to make it such, but that doesn't handle all such cases).

The strings in this situation are three grapheme clusters according to the spec even though they usually render as a single "thingy".