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  1. OMG Issue

DMN13 — Incorrect claim about the Unicode character range and EBNF character expressions

  • Key: DMN13-127
  • Status: open  
  • Source: Fujitsu ( Keith Swenson)
  • Summary:

    This is a trivial typo, and the fix is easy.

    Lower on page 108 it says: "the character range that includes all Unicode characters is [\u0-\u10FFF]." This range specified has less than 70,000 characters.

    I don't think your intent is to limit implementations to 70K characters and in fact in places (e.g. grammar rule #30) character values larger than this are mentioned.

    "all Unicode characters" is actually the entire range of 32-bit values (minus some control codes: hundreds of millions of characters, most of which are undefined). Instead you are defining a SUBSET of this that will be allowed.

    Second, the most common implementation of Unicode uses UTF-16, and as a consequences OF THIS ENCODING, the range of representable characters is 0 through 10FFFF. Note that is six hex digits, there are four F digits. There are over a million characters in this range.

    (1) Nowhere in the spec does is say you are limiting characters to the UTF-16 range. This should be explicitly stated if that is your intent.

    (2) The phrase on page 108 should be changed to; "DMN allows the use of unicode characters in the range of [\u0-\u10FFFF]."

    (3) The specification of EBNF character expression should be changed to allow 6 hex digits, currently it says you can only use five digits max.

  • Reported: DMN 1.2b1 — Mon, 31 Dec 2018 17:00 GMT
  • Updated: Tue, 18 Jun 2019 16:27 GMT