+ <sect2 id="unicode-syntax">
+ <title>Unicode syntax</title>
+ <para>The language
+ extension <option>-XUnicodeSyntax</option><indexterm><primary><option>-XUnicodeSyntax</option></primary></indexterm>
+ enables Unicode characters to be used to stand for certain ASCII
+ character sequences. The following alternatives are provided:</para>
+
+ <informaltable>
+ <tgroup cols="2" align="left" colsep="1" rowsep="1">
+ <thead>
+ <row>
+ <entry>ASCII</entry>
+ <entry>Unicode alternative</entry>
+ <entry>Code point</entry>
+ <entry>Name</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry><literal>::</literal></entry>
+ <entry>::</entry> <!-- no special char, apparently -->
+ <entry>0x2237</entry>
+ <entry>PROPORTION</entry>
+ </row>
+ </tbody>
+ <tbody>
+ <row>
+ <entry><literal>=></literal></entry>
+ <entry>⇒</entry>
+ <entry>0x21D2</entry>
+ <entry>RIGHTWARDS DOUBLE ARROW</entry>
+ </row>
+ </tbody>
+ <tbody>
+ <row>
+ <entry><literal>forall</literal></entry>
+ <entry>∀</entry>
+ <entry>0x2200</entry>
+ <entry>FOR ALL</entry>
+ </row>
+ </tbody>
+ <tbody>
+ <row>
+ <entry><literal>-></literal></entry>
+ <entry>→</entry>
+ <entry>0x2192</entry>
+ <entry>RIGHTWARDS ARROW</entry>
+ </row>
+ </tbody>
+ <tbody>
+ <row>
+ <entry><literal><-</literal></entry>
+ <entry>←</entry>
+ <entry>0x2190</entry>
+ <entry>LEFTWARDS ARROW</entry>
+ </row>
+ </tbody>
+ <tbody>
+ <row>
+ <entry>..</entry>
+ <entry>…</entry>
+ <entry>0x22EF</entry>
+ <entry>MIDLINE HORIZONTAL ELLIPSIS</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </informaltable>
+ </sect2>
+
+ <sect2 id="magic-hash">
+ <title>The magic hash</title>
+ <para>The language extension <option>-XMagicHash</option> allows "#" as a
+ postfix modifier to identifiers. Thus, "x#" is a valid variable, and "T#" is
+ a valid type constructor or data constructor.</para>
+
+ <para>The hash sign does not change sematics at all. We tend to use variable
+ names ending in "#" for unboxed values or types (e.g. <literal>Int#</literal>),
+ but there is no requirement to do so; they are just plain ordinary variables.
+ Nor does the <option>-XMagicHash</option> extension bring anything into scope.
+ For example, to bring <literal>Int#</literal> into scope you must
+ import <literal>GHC.Prim</literal> (see <xref linkend="primitives"/>);
+ the <option>-XMagicHash</option> extension
+ then allows you to <emphasis>refer</emphasis> to the <literal>Int#</literal>
+ that is now in scope.</para>
+ <para> The <option>-XMagicHash</option> also enables some new forms of literals (see <xref linkend="glasgow-unboxed"/>):
+ <itemizedlist>
+ <listitem><para> <literal>'x'#</literal> has type <literal>Char#</literal></para> </listitem>
+ <listitem><para> <literal>"foo"#</literal> has type <literal>Addr#</literal></para> </listitem>
+ <listitem><para> <literal>3#</literal> has type <literal>Int#</literal>. In general,
+ any Haskell 98 integer lexeme followed by a <literal>#</literal> is an <literal>Int#</literal> literal, e.g.
+ <literal>-0x3A#</literal> as well as <literal>32#</literal></para>.</listitem>
+ <listitem><para> <literal>3##</literal> has type <literal>Word#</literal>. In general,
+ any non-negative Haskell 98 integer lexeme followed by <literal>##</literal>
+ is a <literal>Word#</literal>. </para> </listitem>
+ <listitem><para> <literal>3.2#</literal> has type <literal>Float#</literal>.</para> </listitem>
+ <listitem><para> <literal>3.2##</literal> has type <literal>Double#</literal></para> </listitem>
+ </itemizedlist>
+ </para>
+ </sect2>
+
+ <sect2 id="new-qualified-operators">
+ <title>New qualified operator syntax</title>
+
+ <para>A new syntax for referencing qualified operators is
+ planned to be introduced by Haskell', and is enabled in GHC
+ with
+ the <option>-XNewQualifiedOperators</option><indexterm><primary><option>-XNewQualifiedOperators</option></primary></indexterm>
+ option. In the new syntax, the prefix form of a qualified
+ operator is
+ written <literal><replaceable>module</replaceable>.(<replaceable>symbol</replaceable>)</literal>
+ (in Haskell 98 this would
+ be <literal>(<replaceable>module</replaceable>.<replaceable>symbol</replaceable>)</literal>),
+ and the infix form is
+ written <literal>`<replaceable>module</replaceable>.(<replaceable>symbol</replaceable>)`</literal>
+ (in Haskell 98 this would
+ be <literal>`<replaceable>module</replaceable>.<replaceable>symbol</replaceable>`</literal>.
+ For example:
+<programlisting>
+ add x y = Prelude.(+) x y
+ subtract y = (`Prelude.(-)` y)
+</programlisting>
+ The new form of qualified operators is intended to regularise
+ the syntax by eliminating odd cases
+ like <literal>Prelude..</literal>. For example,
+ when <literal>NewQualifiedOperators</literal> is on, it is possible to
+ write the enumerated sequence <literal>[Monday..]</literal>
+ without spaces, whereas in Haskell 98 this would be a
+ reference to the operator ‘<literal>.</literal>‘
+ from module <literal>Monday</literal>.</para>
+
+ <para>When <option>-XNewQualifiedOperators</option> is on, the old Haskell
+ 98 syntax for qualified operators is not accepted, so this
+ option may cause existing Haskell 98 code to break.</para>
+
+ </sect2>
+
+