TIP 388 implementation

1 files changed, 16 insertions, 13 deletions

diff --git a/doc/re_syntax.n b/doc/re_syntax.n
index 8701641..a53f58b 100644
--- a/doc/re_syntax.n
+++ b/doc/re_syntax.n
@@ -359,39 +359,42 @@ horizontal tab, as in C
 .TP
 \fB\eu\fIwxyz\fR
 .
-(where \fIwxyz\fR is exactly four hexadecimal digits) the Unicode
+(where \fIwxyz\fR is one up to four hexadecimal digits) the Unicode
 character \fBU+\fIwxyz\fR in the local byte ordering
 .TP
 \fB\eU\fIstuvwxyz\fR
 .
-(where \fIstuvwxyz\fR is exactly eight hexadecimal digits) reserved
-for a somewhat-hypothetical Unicode extension to 32 bits
+(where \fIstuvwxyz\fR is one up to eight hexadecimal digits) reserved
+for a Unicode extension up to 21 bits. The digits are parsed until the
+first non-hexadecimal character is encountered, the maximun of eight
+hexadecimal digits are reached, or an overflow would occur in the maximum
+value of \fBU+\fI10ffff\fR.
 .TP
 \fB\ev\fR
 .
 vertical tab, as in C are all available.
 .TP
-\fB\ex\fIhhh\fR
+\fB\ex\fIhh\fR
 .
-(where \fIhhh\fR is any sequence of hexadecimal digits) the character
-whose hexadecimal value is \fB0x\fIhhh\fR (a single character no
-matter how many hexadecimal digits are used).
+(where \fIhh\fR is one or two hexadecimal digits) the character
+whose hexadecimal value is \fB0x\fIhh\fR.
 .TP
 \fB\e0\fR
 .
 the character whose value is \fB0\fR
 .TP
+\fB\e\fIxyz\fR
+.
+(where \fIxyz\fR is exactly three octal digits, and is not a \fIback
+reference\fR (see below)) the character whose octal value is
+\fB0\fIxyz\fR. The first digit must be in the range 0-3, otherwise
+the two-digit form is assumed.
+.TP
 \fB\e\fIxy\fR
 .
 (where \fIxy\fR is exactly two octal digits, and is not a \fIback
 reference\fR (see below)) the character whose octal value is
 \fB0\fIxy\fR
-.TP
-\fB\e\fIxyz\fR
-.
-(where \fIxyz\fR is exactly three octal digits, and is not a back
-reference (see below)) the character whose octal value is
-\fB0\fIxyz\fR
 .RE
 .PP
 Hexadecimal digits are