[m-rev.] for review: undocument support for \u escape sequences

[Ian MacLarty]

For review by Simon Taylor.  I've included both the changes to the mercury
respository and the w3 repository in this email.

Estimated time taken: 0.1
Branches: main

NEWS:
doc/reference_manual.texi:
	Undocument the \u and \U escape sequences because of objections from
	Simon Taylor
	(http://www.cs.mu.oz.au/research/mercury/mailing-lists/mercury-developers/mercury-developers.200703/0002.html).

Index: NEWS
===================================================================
RCS file: /home/mercury1/repository/mercury/NEWS,v
retrieving revision 1.449
diff -u -r1.449 NEWS
--- NEWS	2 Mar 2007 02:56:36 -0000	1.449
+++ NEWS	6 Mar 2007 02:40:13 -0000
@@ -12,8 +12,6 @@
   terms.
 * Mutables can now be marked as thread-local, which can take on different
   values for each thread.
-* Unicode characters can now be encoded in string literals using an
-  escape sequence.
 * promise_equivalent_solutions scopes (et al.) must now also list variables
   with inst any that may be constrained by the goal.
 
@@ -200,13 +198,6 @@
 		...
 		% perform the actual task
 
-* Unicode characters can now be encoded in string literals using an
-  escape sequence.  The escape sequence \uXXXX (or \UXXXXXXXX), where XXXX
-  (or XXXXXXXX) is a Unicode character code in hexadecimal, is replaced with
-  the corresponding Unicode character.  The encoding used to represent the
-  Unicode character is implementation dependent.  For the Melbourne Mercury
-  compiler, Unicode characters are represented using UTF-8 for the C backends.
-
 Changes to the Mercury compiler:
 
 * The compiler now issues a warning when an inst declaration isn't
Index: doc/reference_manual.texi
===================================================================
RCS file: /home/mercury1/repository/mercury/doc/reference_manual.texi,v
retrieving revision 1.387
diff -u -r1.387 reference_manual.texi
--- doc/reference_manual.texi	4 Mar 2007 23:38:07 -0000	1.387
+++ doc/reference_manual.texi	6 Mar 2007 02:39:55 -0000
@@ -242,14 +242,16 @@
 beginning of an octal escape; as with hexadecimal escapes, the sequence
 of octal digits must be terminated with a closing backslash.
 
-The sequence @samp{\u} or @samp{\U} can be used to escape Unicode characters.
- at samp{\u} must be followed by the Unicode character code expressed as four
-hexadecimal digits.
- at samp{\U} must be followed by the Unicode character code expressed as eight
-hexadecimal digits.
-The encoding used for Unicode characters is implementation dependent.
-For the Melbourne Mercury compiler, it is UTF-8 for the C backends and UTF-16
-for the Java and IL backends.
+ at c XXX The following feature is undocumented until we have more complete
+ at c support for unicode.
+ at c The sequence @samp{\u} or @samp{\U} can be used to escape Unicode characters.
+ at c @samp{\u} must be followed by the Unicode character code expressed as four
+ at c hexadecimal digits.
+ at c @samp{\U} must be followed by the Unicode character code expressed as eight
+ at c hexadecimal digits.
+ at c The encoding used for Unicode characters is implementation dependent.
+ at c For the Melbourne Mercury compiler, it is UTF-8 for the C backends and UTF-16
+ at c for the Java and IL backends.
 
 A backslash followed immediately by a newline is deleted; thus an
 escaped newline can be used to continue a string over more than one

========================================================================

Estimated hours taken: 0.1

news/newsdb.inc:
	Mention that support for unicode escape sequences has been removed.

Index: news/newsdb.inc
===================================================================
RCS file: /home/mercury1/repository/w3/news/newsdb.inc,v
retrieving revision 1.100
diff -u -r1.100 newsdb.inc
--- news/newsdb.inc	4 Dec 2006 04:22:38 -0000	1.100
+++ news/newsdb.inc	6 Mar 2007 02:47:31 -0000
@@ -22,6 +22,11 @@
 
 $newsdb = array(
 
+"6 March 2007" => array("Remove support for Unicode characters in string literals",
+
+"This feature has been removed because of concerns that it might lead users
+to believe that Mercury offers full Unicode support, which is not the case."),
+
 "1 December 2006" => array("Mercury 0.13.1 released",
 
 "Release information is available
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