the number of bits specified by the right argument. Arguments should
be integers. (See also L<Integer Arithmetic>.)
+Note that both "<<" and ">>" in Perl are implemented directly using
+"<<" and ">>" in C. If C<use integer> (see L<Integer Arithmetic>) is
+in force then signed C integers are used, else unsigned C integers are
+used. Either way, the implementation isn't going to generate results
+larger than the size of the integer type Perl was built with (32 bits
+or 64 bits).
+
+The result of overflowing the range of the integers is undefined
+because it is undefined also in C. In other words, using 32-bit
+integers, C<< 1 << 32 >> is undefined. Shifting by a negative number
+of bits is also undefined.
+
=head2 Named Unary Operators
The various named unary operators are treated as functions with one
Customary Generic Meaning Interpolates
'' q{} Literal no
"" qq{} Literal yes
- `` qx{} Command yes (unless '' is delimiter)
+ `` qx{} Command yes*
qw{} Word list no
- // m{} Pattern match yes (unless '' is delimiter)
- qr{} Pattern yes (unless '' is delimiter)
- s{}{} Substitution yes (unless '' is delimiter)
+ // m{} Pattern match yes*
+ qr{} Pattern yes*
+ s{}{} Substitution yes*
tr{}{} Transliteration no (but see below)
+ * unless the delimiter is ''.
+
Non-bracketing delimiters use the same character fore and aft, but the four
sorts of brackets (round, angle, square, curly) will all nest, which means
that
$s = q{ if($a eq "}") ... }; # WRONG
-is a syntax error. The C<Text::Balanced> module on CPAN is able to do this
-properly.
+is a syntax error. The C<Text::Balanced> module (from CPAN, and
+starting from Perl 5.8 part of the standard distribution) is able
+to do this properly.
There can be whitespace between the operator and the quoting
characters, except when C<#> is being used as the quoting character.
s {foo} # Replace foo
{bar} # with bar.
-For constructs that do interpolate, variables beginning with "C<$>"
-or "C<@>" are interpolated, as are the following escape sequences. Within
-a transliteration, the first eleven of these sequences may be used.
+The following escape sequences are available in constructs that interpolate
+and in transliterations.
\t tab (HT, TAB)
\n newline (NL)
\c[ control char (ESC)
\N{name} named char
+The following escape sequences are available in constructs that interpolate
+but not in transliterations.
+
\l lowercase next char
\u uppercase next char
\L lowercase till \E
C<"\015">. If you get in the habit of using C<"\n"> for networking,
you may be burned some day.
+For constructs that do interpolate, variables beginning with "C<$>"
+or "C<@>" are interpolated. Subscripted variables such as C<$a[3]> or
+C<$href->{key}[0]> are also interpolated, as are array and hash slices.
+But method calls such as C<$obj->meth> are not.
+
+Interpolating an array or slice interpolates the elements in order,
+separated by the value of C<$">, so is equivalent to interpolating
+C<join $", @array>. "Punctuation" arrays such as C<@+> are only
+interpolated if the name is enclosed in braces C<@{+}>.
+
You cannot include a literal C<$> or C<@> within a C<\Q> sequence.
An unescaped C<$> or C<@> interpolates the corresponding variable,
while escaping will cause the literal string C<\$> to be inserted.