I am preparing a new version of the proposal, but I would like to mention separately that, as Martin suggested, it will include a new character to terminate isolates, which I am calling PDI (POP DIRECTIONAL ISOLATE). The question naturally arises how the algorithm should behave when isolates are not properly nested with respect to embeddings/overrides, e.g. a: RLI LRE PDI PDF, and b: RLE LRI PDF PDI. There are basically two possibilities: 1. Make isolates weaker than embeddings/overrides, i.e. ignore a PDI when a PDF is expected, and have a PDF close all isolates opened between it and its marching LRE/RLE/LRO/RLO. Thus, in a, the PDI is ignored, and in b, the PDF ends the scope of the RLI as well as the LRE. 2. Vice-versa - make isolates stronger than embeddings/overrides, i.e. ignore a PDF when a PDI is expected, and have a PDI close all embeddings/overrides opened between it and its marching FSI/LRI/RLI. Thus, in a, the PDI ends the scope of the RLE as well as the LRI, and in b, the PDF is ignored. Possibility 2 offers greater forward compatibility, since new and old apps will interpret the PDFs as closing the same scopes when isolates are not properly nested with respect to embeddings/overrides. Possibility 1, on the other hand, gives isolates the desirable feature of isolating their surroundings from their contents - even when their contents contains extra or missing PDFs. I have decided to go with possibility 2, since IMO forward compatibility is not very important for what are, essentially, broken documents. Aharon On Tue, May 15, 2012 at 11:10 AM, "Martin J. Dürst" <duerst@it.aoyama.ac.jp>wrote: > It may be worth considering to create a new character to close these > embeddings. Otherwise, older algorithms will close LRE/RLE/LRO/RLO > embeddings/overrides prematurely. >Received on Sunday, 8 July 2012 13:53:32 UTC
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