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| author | Björn Gustavsson <[email protected]> | 2011-08-30 11:51:11 +0200 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2011-10-13 14:16:00 +0200 |
| commit | 34db76765561487e526fe66d3d19ecf3b3fb9dc8 (patch) | |
| tree | 9141e3c5729e46d03c8b27b14da3b29b1e54abca /system/doc | |
| parent | 6ca6dd3c670fb8185ebb9a20c2a731a7375c1cac (diff) | |
| download | otp-34db76765561487e526fe66d3d19ecf3b3fb9dc8.tar.gz otp-34db76765561487e526fe66d3d19ecf3b3fb9dc8.tar.bz2 otp-34db76765561487e526fe66d3d19ecf3b3fb9dc8.zip | |
Allow noncharacter code points in unicode encoding and decoding
The two noncharacter code points 16#FFFE and 16#FFFF were not
allowed to be encoded or decoded using the unicode module or
bit syntax. That causes an inconsistency, since the noncharacters
16#FDD0 to 16#FDEF could be encoded/decoded.
There is two ways to fix that inconsistency.
We have chosen to allow 16#FFFE and 16#FFFF to be encoded and
decoded, because the noncharacters could be useful internally
within an application and it will make encoding and decoding
slightly faster.
Reported-by: Alisdair Sullivan
Diffstat (limited to 'system/doc')
| -rw-r--r-- | system/doc/reference_manual/expressions.xml | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/system/doc/reference_manual/expressions.xml b/system/doc/reference_manual/expressions.xml index 497d7eb464..644896cd7f 100644 --- a/system/doc/reference_manual/expressions.xml +++ b/system/doc/reference_manual/expressions.xml @@ -879,9 +879,8 @@ Ei = Value | and UTF-32, respectively.</p> <p>When constructing a segment of a <c>utf</c> type, <c>Value</c> - must be an integer in one of the ranges 0..16#D7FF, - 16#E000..16#FFFD, or 16#10000..16#10FFFF - (i.e. a valid Unicode code point). Construction + must be an integer in the range 0..16#D7FF or + 16#E000....16#10FFFF. Construction will fail with a <c>badarg</c> exception if <c>Value</c> is outside the allowed ranges. The size of the resulting binary segment depends on the type and/or <c>Value</c>. For <c>utf8</c>, @@ -896,14 +895,13 @@ Ei = Value | <c><![CDATA[<<$a/utf8,$b/utf8,$c/utf8>>]]></c>.</p> <p>A successful match of a segment of a <c>utf</c> type results - in an integer in one of the ranges 0..16#D7FF, 16#E000..16#FFFD, - or 16#10000..16#10FFFF - (i.e. a valid Unicode code point). The match will fail if returned value + in an integer in the range 0..16#D7FF or 16#E000..16#10FFFF. + The match will fail if returned value would fall outside those ranges.</p> <p>A segment of type <c>utf8</c> will match 1 to 4 bytes in the binary, if the binary at the match position contains a valid UTF-8 sequence. - (See RFC-2279 or the Unicode standard.)</p> + (See RFC-3629 or the Unicode standard.)</p> <p>A segment of type <c>utf16</c> may match 2 or 4 bytes in the binary. The match will fail if the binary at the match position does not contain |