(W ambiguous) You wrote something like C<@{foo}>, which might be
asking for the variable C<@foo>, or it might be calling a function
named foo, and dereferencing it as an array reference. If you wanted
-the varable, you can just write C<@foo>. If you wanted to call the
+the variable, you can just write C<@foo>. If you wanted to call the
function, write C<@{foo()}> ... or you could just not have a variable
and a function with the same name, and save yourself a lot of trouble.
(P) An internal request asked to add a dirhandle entry to something
that wasn't a symbol table entry.
-
=item Bad symbol for filehandle
(P) An internal request asked to add a filehandle entry to something
forgot to load the corresponding C<charnames> pragma?
See L<charnames>.
-
=item Constant is not %s reference
(F) A constant value (perhaps declared using the C<use constant> pragma)
(F) The method which overloads "=" is buggy. See
L<overload/Copy Constructor>.
+=item &CORE::%s cannot be called directly
+
+(F) You tried to call a subroutine in the C<CORE::> namespace
+with C<&foo> syntax or through a reference. Most subroutines
+in this package cannot yet be called that way, but must be
+called as barewords. Something like this will work:
+
+ BEGIN { *shove = \&CORE::push; }
+ shove @array, 1,2,3; # pushes on to @array
+
=item CORE::%s is not a keyword
(F) The CORE:: namespace is reserved for Perl keywords.
=item defined(%hash) is deprecated
-(D deprecated) defined() is not usually useful on hashes because it
-checks for an undefined I<scalar> value. If you want to see if the hash
-is empty, just use C<if (%hash) { # not empty }> for example.
+(D deprecated) C<defined()> is not usually right on hashes and has been
+discouraged since 5.004.
+
+Although C<defined %hash> is false on a plain not-yet-used hash, it
+becomes true in several non-obvious circumstances, including iterators,
+weak references, stash names, even remaining true after C<undef %hash>.
+These things make C<defined %hash> fairly useless in practice.
+
+If a check for non-empty is what you wanted then just put it in boolean
+context (see L<perldata/Scalar values>):
+
+ if (%hash) {
+ # not empty
+ }
+
+If you had C<defined %Foo::Bar::QUUX> to check whether such a package
+variable exists then that's never really been reliable, and isn't
+a good way to enquire about the features of a package, or whether
+it's loaded, etc.
+
=item (?(DEFINE)....) does not allow branches in regex; marked by <-- HERE in m/%s/
(W overflow) You called C<gmtime> with a number that was larger than
it can reliably handle and C<gmtime> probably returned the wrong
-date. This warning is also triggered with nan (the special
+date. This warning is also triggered with NaN (the special
not-a-number value).
=item gmtime(%f) too small
(W overflow) You called C<gmtime> with a number that was smaller than
it can reliably handle and C<gmtime> probably returned the wrong
-date. This warning is also triggered with nan (the special
+date. This warning is also triggered with NaN (the special
not-a-number value).
=item Got an error from DosAllocMem
binary number. Interpretation of the binary number stopped before the
offending digit.
+=item Illegal character after '_' in prototype for %s : %s
+
+(W illegalproto) An illegal character was found in a prototype declaration.
+Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
+
=item Illegal character \%o (carriage return)
(F) Perl normally treats carriage returns in the program text as it
function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
-
=item Integer overflow in format string for %s
(F) The indexes and widths specified in the format string of C<printf()>
(W overflow) You called C<localtime> with a number that was larger
than it can reliably handle and C<localtime> probably returned the
-wrong date. This warning is also triggered with nan (the special
+wrong date. This warning is also triggered with NaN (the special
not-a-number value).
=item localtime(%f) too small
(W overflow) You called C<localtime> with a number that was smaller
than it can reliably handle and C<localtime> probably returned the
-wrong date. This warning is also triggered with nan (the special
+wrong date. This warning is also triggered with NaN (the special
not-a-number value).
=item Lookbehind longer than %d not implemented in regex m/%s/
by that? lstat() makes sense only on filenames. (Perl did a fstat()
instead on the filehandle.)
-=item lvalue attribute ignored after the subroutine has been defined
+=item lvalue attribute cannot be removed after the subroutine has been defined
-(W misc) Making a subroutine an lvalue subroutine after it has been defined
-by declaring the subroutine with an lvalue attribute is not
-possible. To make the subroutine an lvalue subroutine add the
-lvalue attribute to the definition, or put the declaration before
-the definition.
+(W misc) The lvalue attribute on a Perl subroutine cannot be turned off
+once the subroutine is defined.
-=item Lvalue subs returning %s not implemented yet
+=item lvalue attribute ignored after the subroutine has been defined
-(F) Due to limitations in the current implementation, array and hash
-values cannot be returned in subroutines used in lvalue context. See
-L<perlsub/"Lvalue subroutines">.
+(W misc) Making a Perl subroutine an lvalue subroutine after it has been
+defined, whether by declaring the subroutine with an lvalue attribute
+or by using L<attributes.pm|attributes>, is not possible. To make the subroutine an
+lvalue subroutine, add the lvalue attribute to the definition, or put
+the declaration before the definition.
=item Malformed integer in [] in pack
Occasionally the line number may be misleading, and once in a blue moon
the only way to figure out what's triggering the error is to call
C<perl -c> repeatedly, chopping away half the program each time to see
-if the error went away. Sort of the cybernetic version of S<20
-questions>.
+if the error went away. Sort of the cybernetic version of S<20 questions>.
=item syntax error at line %d: `%s' unexpected
(F) You called a Win32 function with incorrect arguments.
See L<Win32> for more information.
+=item Useless assignment to a temporary
+
+(W misc) You assigned to an lvalue subroutine, but what
+the subroutine returned was a temporary scalar about to
+be discarded, so the assignment had no effect.
+
=item Useless (?-%s) - don't use /%s modifier in regex; marked by <-- HERE in m/%s/
(W regexp) You have used an internal modifier such as (?-o) that has no
been decided. (Simply returning the boolean opposite of the
modified string is usually not particularly useful.)
-=item User-defined case-mapping '%s' is deprecated
-
-(W deprecated) You defined a function, such as C<ToLower> that overrides
-the standard case mapping, such as C<lc()> gives. This feature is being
-deprecated due to its many issues, as documented in
-L<perlunicode/User-Defined Case Mappings (for serious hackers only)>.
-It is planned to remove this feature in Perl 5.16. A CPAN module
-providing improved functionality is being prepared.
-
=item UTF-16 surrogate U+%X
(W utf8, surrogate) You had a UTF-16 surrogate in a context where they are
=head1 SEE ALSO
-L<warnings>, L<perllexwarn>.
+L<warnings>, L<perllexwarn>, L<diagnostics>.
=cut
https://perl5.git.perl.org / perl5.git / blobdiff