move doc about v-strings from perlop to perldata (suggested by

[p5sagit/p5-mst-13.2.git] / pod / perldata.pod

diff --git a/pod/perldata.pod b/pod/perldata.pod
index a122d34..4dbc765 100644 (file)
--- a/pod/perldata.pod
+++ b/pod/perldata.pod
@@ -274,6 +274,7 @@ integer formats:
     0xff                # hex
     0377                # octal
     0b011011            # binary
+    v102.111.111        # string (made of characters "f", "o", "o")
 
 String literals are usually delimited by either single or double
 quotes.  They work much like quotes in the standard Unix shells:
@@ -323,6 +324,17 @@ C<$days{Feb}> and the quotes will be assumed automatically.  But
 anything more complicated in the subscript will be interpreted as
 an expression.
 
+A literal of the form C<v1.20.300.4000> is parsed as a string composed
+of characters with the specified ordinals.  This provides an alternative,
+more readable way to construct strings, rather than use the somewhat less
+readable interpolation form C<"\x{1}\x{14}\x{12c}\x{fa0}">.  This is useful
+for representing Unicode strings, and for comparing version "numbers"
+using the string comparison operators, C<cmp>, C<gt>, C<lt> etc.
+If there are two or more dots in the literal, the leading C<v> may be
+omitted.  Such literals are accepted by both C<require> and C<use> for
+doing a version check.  The C<$^V> special variable also contains the
+running Perl interpreter's version in this form.  See L<perlvar/$^V>.
+
 The special literals __FILE__, __LINE__, and __PACKAGE__
 represent the current filename, line number, and package name at that
 point in your program.  They may be used only as separate tokens; they