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<H1> 4.2 Literals</H1>
<DIV Class="Paranum"><FONT SIZE=-2>1</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2237"></A>A <I>literal</I> represents
a value literally, that is, by means of notation suited to its kind.
A literal is either a <FONT FACE="Arial, Helvetica">numeric_literal</FONT>,
a <FONT FACE="Arial, Helvetica">character_literal</FONT>, the literal
<B>null</B>, or a <FONT FACE="Arial, Helvetica">string_literal</FONT>.
<A NAME="I2238"></A></DIV>
<H4 ALIGN=CENTER>Name Resolution Rules</H4>
<DIV Class="Paranum"><FONT SIZE=-2>2</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2239"></A>The expected type for a literal
<B>null</B> shall be a single access type. </DIV>
<DIV Class="Paranum"><FONT SIZE=-2>3</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2240"></A><A NAME="I2241"></A>For a
<FONT FACE="Arial, Helvetica">name</FONT> that consists of a <FONT FACE="Arial, Helvetica">character_literal</FONT>,
either its expected type shall be a single character type, in which case
it is interpreted as a parameterless <FONT FACE="Arial, Helvetica">function_call</FONT>
that yields the corresponding value of the character type, or its expected
profile shall correspond to a parameterless function with a character
result type, in which case it is interpreted as the name of the corresponding
parameterless function declared as part of the character type's definition
(see <A HREF="RM-3-5-1.html">3.5.1</A>). In either case, the <FONT FACE="Arial, Helvetica">character_literal</FONT>
denotes the <FONT FACE="Arial, Helvetica">enumeration_literal_specification</FONT>.
</DIV>
<DIV Class="Paranum"><FONT SIZE=-2>4</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2242"></A>The expected type for a <FONT FACE="Arial, Helvetica">primary</FONT>
that is a <FONT FACE="Arial, Helvetica">string_literal</FONT> shall be
a single string type. </DIV>
<H4 ALIGN=CENTER>Legality Rules</H4>
<DIV Class="Paranum"><FONT SIZE=-2>5</FONT></DIV>
<DIV Class="Normal"> A <FONT FACE="Arial, Helvetica">character_literal</FONT>
that is a <FONT FACE="Arial, Helvetica">name</FONT> shall correspond
to a <FONT FACE="Arial, Helvetica">defining_character_literal</FONT>
of the expected type, or of the result type of the expected profile.</DIV>
<DIV Class="Paranum"><FONT SIZE=-2>6</FONT></DIV>
<DIV Class="Normal"> For each character of a <FONT FACE="Arial, Helvetica">string_literal</FONT>
with a given expected string type, there shall be a corresponding <FONT FACE="Arial, Helvetica">defining_character_literal</FONT>
of the component type of the expected string type.</DIV>
<DIV Class="Paranum"><FONT SIZE=-2>7</FONT></DIV>
<DIV Class="Normal"> A literal <FONT FACE="Arial, Helvetica">null</FONT>
shall not be of an anonymous access type, since such types do not have
a null value (see <A HREF="RM-3-10.html">3.10</A>). </DIV>
<H4 ALIGN=CENTER>Static Semantics</H4>
<DIV Class="Paranum"><FONT SIZE=-2>8</FONT></DIV>
<DIV Class="Normal"> An integer literal is of type <I>universal_integer</I>.
A real literal is of type <I>universal_real</I>.</DIV>
<H4 ALIGN=CENTER>Dynamic Semantics</H4>
<DIV Class="Paranum"><FONT SIZE=-2>9</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2243"></A><A NAME="I2244"></A><A NAME="I2245"></A><A NAME="I2246"></A>The
evaluation of a numeric literal, or the literal <B>null</B>, yields the
represented value.</DIV>
<DIV Class="Paranum"><FONT SIZE=-2>10</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2247"></A>The evaluation of a <FONT FACE="Arial, Helvetica">string_literal</FONT>
that is a <FONT FACE="Arial, Helvetica">primary</FONT> yields an array
value containing the value of each character of the sequence of characters
of the <FONT FACE="Arial, Helvetica">string_literal</FONT>, as defined
in <A HREF="RM-2-6.html">2.6</A>. The bounds of this array value are
determined according to the rules for <FONT FACE="Arial, Helvetica">positional_array_aggregate</FONT>s
(see <A HREF="RM-4-3-3.html">4.3.3</A>), except that for a null string
literal, the upper bound is the predecessor of the lower bound.</DIV>
<DIV Class="Paranum"><FONT SIZE=-2>11</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2248"></A><A NAME="I2249"></A>For the
evaluation of a <FONT FACE="Arial, Helvetica">string_literal</FONT> of
type <I>T</I>, a check is made that the value of each character of the
<FONT FACE="Arial, Helvetica">string_literal</FONT> belongs to the component
subtype of <I>T</I>. For the evaluation of a null string literal, a check
is made that its lower bound is greater than the lower bound of the base
range of the index type. <A NAME="I2250"></A>The exception Constraint_Error
is raised if either of these checks fails. </DIV>
<DIV Class="NotesHeader"><FONT SIZE=-1>NOTES</FONT></DIV>
<DIV Class="Paranum"><FONT SIZE=-2>12</FONT></DIV>
<DIV Class="Notes"><FONT SIZE=-1>6 Enumeration literals that
are <FONT FACE="Arial, Helvetica">identifier</FONT>s rather than <FONT FACE="Arial, Helvetica">character_literal</FONT>s
follow the normal rules for <FONT FACE="Arial, Helvetica">identifier</FONT>s
when used in a <FONT FACE="Arial, Helvetica">name</FONT> (see <A HREF="RM-4-1.html">4.1</A>
and <A HREF="RM-4-1-3.html">4.1.3</A>). <FONT FACE="Arial, Helvetica">Character_literal</FONT>s
used as <FONT FACE="Arial, Helvetica">selector_name</FONT>s follow the
normal rules for expanded names (see <A HREF="RM-4-1-3.html">4.1.3</A>).
</FONT></DIV>
<H4 ALIGN=CENTER>Examples</H4>
<DIV Class="Paranum"><FONT SIZE=-2>13</FONT></DIV>
<DIV Class="Normal" Style="margin-bottom: 0.4em"> <I>Examples of
literals:</I> </DIV>
<DIV Class="Paranum"><FONT SIZE=-2>14</FONT></DIV>
<DIV Class="Examples"><TT>3.14159_26536 <I>-- a real literal</I><BR>
1_345 <I>-- an integer literal</I><BR>
'A' <I>-- a character literal</I><BR>
"Some Text" <I>-- a string literal </I></TT></DIV>
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