Improve handling of nested qr/(?[...])/

[perl5.git] / pod / perldiag.pod

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index c5e7a62..fa51f1d 100644 (file)
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -2292,36 +2292,18 @@ to denote a capturing group of the form
 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
 but omitted the C<")">.
 
-=item Expecting close paren for nested extended charclass in regex; marked
-by <-- HERE in m/%s/
-
-(F) While parsing a nested extended character class like:
-
-    (?[ ... (?flags:(?[ ... ])) ... ])
-                             ^
-
-we expected to see a close paren ')' (marked by ^) but did not.
-
-=item Expecting close paren for wrapper for nested extended charclass in
-regex; marked by <-- HERE in m/%s/
-
-(F) While parsing a nested extended character class like:
-
-    (?[ ... (?flags:(?[ ... ])) ... ])
-                              ^
+=item Expecting interpolated extended charclass in regex; marked by <--
+HERE in m/%s/
 
-we expected to see a close paren ')' (marked by ^) but did not.
+(F) It looked like you were attempting to interpolate an
+already-compiled extended character class, like so:
 
-=item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
+ my $thai_or_lao = qr/(?[ \p{Thai} + \p{Lao} ])/;
+ ...
+ qr/(?[ \p{Digit} & $thai_or_lao ])/;
 
-(F) The C<(?[...])> extended character class regular expression construct
-only allows character classes (including character class escapes like
-C<\d>), operators, and parentheses.  The one exception is C<(?flags:...)>
-containing at least one flag and exactly one C<(?[...])> construct.
-This allows a regular expression containing just C<(?[...])> to be
-interpolated.  If you see this error message, then you probably
-have some other C<(?...)> construct inside your character class.  See
-L<perlrecharclass/Extended Bracketed Character Classes>.
+But the marked code isn't syntactically correct to be such an
+interpolated class.
 
 =item Experimental aliasing via reference not enabled
 
@@ -4396,6 +4378,13 @@ the braces.
 or printf() would have been too large for the underlying C function to
 report.  This limit is typically 2GB.
 
+=item Numeric variables with more than one digit may not start with '0'
+
+(F) The only numeric variable which is allowed to start with a 0 is C<$0>,
+and you mentioned a variable that starts with 0 that has more than one
+digit. You probably want to remove the leading 0, or if the intent was
+to express a variable name in octal you should convert to decimal.
+
 =item Octal number > 037777777777 non-portable
 
 (W portable) The octal number you specified is larger than 2**32-1