- From: Najib Tounsi via GitHub <sysbot+gh@w3.org>
- Date: Tue, 08 Nov 2016 12:01:51 +0000
- To: public-i18n-core@w3.org
What is the spec of the zero-width joiner? 1) Unicode-Ch9, Sec 9.2 Arabic, p371 (http://www.unicode.org/versions/Unicode9.0.0/ch09.pdf) says: "... The use of a joiner **adjacent to a suitable** letter permits that letter to form a cursive connection without a **visible neighbor**." and gives a use case "This provides a simple way to encode some special cases, such as exhibiting a connecting form in isolation." Guess that "suitable letter" means those letters who join according to their writing system (e.g. Aleph doesn't join to it's left in Arabic). But what "adjacent" mean? At the right, left or both? "without a visible neighbor" : what about no visible member next? A visible member but separated by space, say? To support the definition, Unicode gives an example of a special case with letter HEH and shows what ZWJ means for that special case. 2) Wikipedia informal définition says: "When placed **between** two characters that **would** otherwise not be connected, a ZWJ causes them to be printed in their connected forms." More explicit but (only?) "between" two letters. When "would" they be not connected. What are those situations? Any way, browsers implementation of ZWJ differs from one another. I noticed that browsers (based Gecko vs. based Webkit) display depends on - font used (Amiri seems to react better), - What letter is neighbour, even if separated by a space - base direction rtl or ltr (!?) Also, letter Ghain behave differently than letter Heh, though they both have four different shapes: initial, medial, final and isolated. Moreover, Gecko implementation is right for "colored letters" within a word (they join). But ZWJ applied to only one letter works better in Webkit implementation : all the four shapes show up . -- GitHub Notification of comment by ntounsi Please view or discuss this issue at https://github.com/w3c/i18n-activity/issues/246#issuecomment-259119169 using your GitHub account
Received on Tuesday, 8 November 2016 12:01:58 UTC