Merge 2022-07 CWG Motion 8

P2290R3 Delimited escape sequences

Author: tkoeppe

source/lex.tex

@@ -293,10 +293,17 @@
     hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit
 \end{bnf}
 
+\begin{bnf}
+\nontermdef{simple-hexadecimal-digit-sequence}\br
+    hexadecimal-digit\br
+    simple-hexadecimal-digit-sequence hexadecimal-digit
+\end{bnf}
+
 \begin{bnf}
 \nontermdef{universal-character-name}\br
     \terminal{\textbackslash u} hex-quad\br
-    \terminal{\textbackslash U} hex-quad hex-quad
+    \terminal{\textbackslash U} hex-quad hex-quad\br
+    \terminal{\textbackslash u\{} simple-hexadecimal-digit-sequence \terminal{\}}
 \end{bnf}
 
 A \grammarterm{universal-character-name}
@@ -1310,17 +1317,25 @@
     hexadecimal-escape-sequence
 \end{bnf}
 
+\begin{bnf}
+\nontermdef{simple-octal-digit-sequence}\br
+    octal-digit\br
+    simple-octal-digit-sequence octal-digit
+\end{bnf}
+
 \begin{bnf}
 \nontermdef{octal-escape-sequence}\br
     \terminal{\textbackslash} octal-digit\br
     \terminal{\textbackslash} octal-digit octal-digit\br
-    \terminal{\textbackslash} octal-digit octal-digit octal-digit
+    \terminal{\textbackslash} octal-digit octal-digit octal-digit\br
+    \terminal{\textbackslash o\{} simple-octal-digit-sequence \terminal{\}}\br
 \end{bnf}
 
 \begin{bnf}
 \nontermdef{hexadecimal-escape-sequence}\br
     \terminal{\textbackslash x} hexadecimal-digit\br
-    hexadecimal-escape-sequence hexadecimal-digit
+    hexadecimal-escape-sequence hexadecimal-digit\br
+    \terminal{\textbackslash x\{} simple-hexadecimal-digit-sequence \terminal{\}}
 \end{bnf}
 
 \begin{bnf}
@@ -1330,7 +1345,7 @@
 
 \begin{bnf}
 \nontermdef{conditional-escape-sequence-char}\br
-    \textnormal{any member of the basic character set that is not an} octal-digit\textnormal{, a} simple-escape-sequence-char\textnormal{, or the characters \terminal{u}, \terminal{U}, or \terminal{x}}
+    \textnormal{any member of the basic character set that is not an} octal-digit\textnormal{, a} simple-escape-sequence-char\textnormal{, or the characters \terminal{o}, \terminal{u}, \terminal{U}, or \terminal{x}}
 \end{bnf}
 
 \pnum