From eaa7fc2ca250747e2a83858929d35320b6b054bc Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Mon, 11 May 2026 23:07:50 +0200
Subject: [PATCH] Document operator and delimiters

---
 doc/appendix.tex |  10 ++---
 doc/language.tex | 103 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+), 5 deletions(-)

diff --git a/doc/appendix.tex b/doc/appendix.tex
index 0777d55..f68eaa2 100644
--- a/doc/appendix.tex
+++ b/doc/appendix.tex
@@ -14,14 +14,14 @@
 
 <binary-digit> = `0' | `1'.
 
-<hex-character> = `\\x' <hex-digit> <hex-digit>.
+<hex-character> = `\\x' <hex-digit> \{<hex-digit>\}.
 
 <escaped-character> = `\\' \\
-	(`n' | `a' | `b' | `t' | `f' | `r' | `v' | `\\' | `\textquotesingle' | `\textquotedbl' | `?\@' | `0').
+	(`n' | `a' | `b' | `t' | `f' | `r' | `v' | `\\' | `\textquotesingle' | `\textquotedbl' | `0').
 
 <printable-character> = \enspace? a printable ASCII character\space?.
 
-<character> = <printable-character> | <escaped-character> | <hex-digit>.
+<character> = <printable-character> | <escaped-character> | <hex-character>.
 
 <identifier> = <letter> \{<letter> | <decimal-digit>\}.
 
@@ -38,10 +38,10 @@
 <real-literal> = <integer-literal> `.\@' <decimal-digit> \{<decimal-digit>\}
 	\alt{} <integer-literal>\} `e' [`+' | `-'] <decimal-digit> \{<decimal-digit>\}.
 
-<string-literal> = `\textquotedbl' \{<character>\} `\textquotedbl'.
-
 <character-literal> = `\textquotesingle' <character> `\textquotesingle'.
 
+<string-literal> = `\textquotedbl' \{<character>\} `\textquotedbl'.
+
 <literal> = <integer-literal> | <word-literal> | <real-literal>
 	\alt{} <string-literal> | <character-literal>
 	\alt{} `true' | `false' | `nil'.
diff --git a/doc/language.tex b/doc/language.tex
index f79e663..cce2fcb 100644
--- a/doc/language.tex
+++ b/doc/language.tex
@@ -77,8 +77,111 @@ Examples:
 
 \section{Strings and characters}
 
+Single \textit{characters} are enclosed in single quotation marks
+(\textquotesingle).\@ \textit{Strings} are sequences of characters enclosed in
+double quotation marks (\textquotedbl). The number of characters in a string is
+called the \textit{the length} of the string.
+
+\begin{grammar}
+<escaped-character> = `\\' \\
+	(`n' | `a' | `b' | `t' | `f' | `r' | `v' | `\\' | `\textquotesingle' | `\textquotedbl' | `0').
+
+<hex-character> = `\\x' <hex-digit> \{<hex-digit>\}.
+
+<character> = <printable-character> | <escaped-character> | <hex-character>.
+
+<character-literal> = `\textquotesingle' <character> `\textquotesingle'.
+
+<string-literal> = `\textquotedbl' \{<character>\} `\textquotedbl'.
+\end{grammar}
+
+Alternatively, a single character may be represented by a
+\textit{escape sequence} (see~\ref{table:escape}), a character combination
+beginning with a backslash (\textbackslash).
+
+\begin{table}[ht]
+\centering
+\begin{tabular}{r l}
+	\textbf{Sequence} & \textbf{Meaning} \\
+	\toprule
+	\verb|\n| & Newline \\
+	\midrule
+	\verb|\a| & Bell \\
+	\midrule
+	\verb|\b| & Backspace \\
+	\midrule
+	\verb|\t| & Horizontal tab \\
+	\midrule
+	\verb|\f| & Form feed \\
+	\midrule
+	\verb|\r| & Carriage return \\
+	\midrule
+	\verb|\v| & Vertical tab \\
+	\midrule
+	\verb|\\| & Backslash \\
+	\midrule
+	\verb|\'| & Single quote \\
+	\midrule
+	\verb|\"| & Double quote \\
+	\midrule
+	\verb|\0| & Null character \\
+	\midrule
+	\verb|\xh…| & Arbitrary hexadecimal value, where \verb|n| is a hexadecimal digit \\
+	\bottomrule
+\end{tabular}
+\caption{Escape sequences}\label{table:escape}
+\end{table}
+
+Examples:
+
+\begin{itemize}
+		\item \verb|"String"|
+		\item \verb|'c'|
+		\item \verb|'\''|
+		\item \verb|"\"multi\nline\nquoted\nstring\""|
+\end{itemize}
+
 \section{Operators and delimiters}
 
+\textit{Operators} and \textit{delimiters} are the special characters, character
+pairs, or reserved words listed below. These reserved words consist exclusively
+of letters and cannot be used in the role of identifiers.
+
+\begin{itemize}
+	\item{}:=
+	\item $@\quad\hat{}\quad\sim$
+	\item $.\quad,\quad;\quad:\quad|$
+	\item $<\quad>\quad>=\quad<=\quad<>\quad=$
+	\item $+\quad-\quad*\quad/$
+	\item $or\quad{}xor\quad\&$
+	\item (\ and\ )
+	\item \lbrack{} and \rbrack{}
+	\item \{ and \}
+	\item Pointer
+	\item module
+	\item import
+	\item type
+	\item const
+	\item var
+	\item begin
+	\item end
+	\item proc
+	\item record
+	\item while
+	\item do
+	\item case
+	\item of
+	\item if
+	\item then
+	\item elsif
+	\item else
+	\item cast
+	\item return
+	\item true
+	\item false
+	\item nil
+\end{itemize}
+
 \section{Comments}
 
 \textit{Comments} may be inserted between any two tokens in a program. They