diff options
Diffstat (limited to 'pod/perldiag.pod')
| -rw-r--r-- | pod/perldiag.pod | 80 |
1 files changed, 45 insertions, 35 deletions
diff --git a/pod/perldiag.pod b/pod/perldiag.pod index c9779243f3..cca35e88bf 100644 --- a/pod/perldiag.pod +++ b/pod/perldiag.pod @@ -726,13 +726,6 @@ which makes no sense. Maybe you meant '%s', or just stringifying it? (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args> is not supported. (Before this error was added, it used to crash.) -=item Cannot smart match without a matcher object - -(F) You tried to perform a smart match (C<~~>), but the right hand operand -was not an object overloading the smart match operation. Such a matcher -object is required, in order to determine what kind of matching operation -to apply to the left hand operand. - =item Cannot tie unreifiable array (P) You somehow managed to call C<tie> on an array that does not @@ -759,6 +752,15 @@ to compress something else. See L<perlfunc/pack>. (F) Only hard references may be blessed. This is how Perl "enforces" encapsulation of objects. See L<perlobj>. +=item Can't "break" in a loop topicalizer + +(F) You called C<break>, but you're in a C<foreach> block rather than +a C<given> block. You probably meant to use C<next> or C<last>. + +=item Can't "break" outside a given block + +(F) You called C<break>, but you're not inside a C<given> block. + =item Can't call method "%s" on an undefined value (F) You used the syntax of a method call, but the slot filled by the @@ -822,10 +824,10 @@ You CAN say but then $foo no longer contains a glob. -=item Can't "continue" outside a whereso block +=item Can't "continue" outside a when block -(F) You called C<continue>, but you're not inside a C<whereis> or -C<whereso> block. +(F) You called C<continue>, but you're not inside a C<when> +or C<default> block. =item Can't create pipe mailbox @@ -837,6 +839,13 @@ quotas or other plumbing problems. (F) Only scalar, array, and hash variables may be declared as "my", "our" or "state" variables. They must have ordinary identifiers as names. +=item Can't "default" outside a topicalizer + +(F) You have used a C<default> block that is neither inside a +C<foreach> loop nor a C<given> block. (Note that this error is +issued on exit from the C<default> block, so you won't get the +error if you use an explicit C<continue>.) + =item Can't determine class of operator %s, assuming BASEOP (S) This warning indicates something wrong in the internals of perl. @@ -1082,17 +1091,6 @@ usually double the curlies to get the same effect though, because the inner curlies will be considered a block that loops once. See L<perlfunc/last>. -=item Can't leave "whereso" outside a loop block - -(F) Control reached the end of a C<whereis> or C<whereso> block that -isn't inside any loop (including a C<given> block). An implicit C<next> -occurs here, which requires a loop to jump to. You probably wanted the -C<whereis> or C<whereso> to be inside a C<given> block. Note that you -won't get this error if the match controlling the C<whereis> or C<whereso> -fails, or if you use an explicit C<continue> to avoid reaching the end -of the block. But if you rely on not reaching the implicit C<next> -then you probably didn't want C<whereis> or C<whereso>, but rather C<if>. - =item Can't linearize anonymous symbol table (F) Perl tried to calculate the method resolution order (MRO) of a @@ -1553,6 +1551,13 @@ instead. (F) You attempted to weaken something that was not a reference. Only references can be weakened. +=item Can't "when" outside a topicalizer + +(F) You have used a when() block that is neither inside a C<foreach> +loop nor a C<given> block. (Note that this error is issued on exit +from the C<when> block, so you won't get the error if the match fails, +or if you use an explicit C<continue>.) + =item Can't x= to read-only value (F) You tried to repeat a constant value (often the undefined value) @@ -2497,9 +2502,10 @@ L<perlfunc/getsockopt>. =item given is experimental -(S experimental::smartmatch) C<given> is experimental, and its behavior -may change or it may even be removed in any future release of perl. -See the explanation under L<perlsyn/Switch Statements>. +(S experimental::smartmatch) C<given> depends on smartmatch, which +is experimental, so its behavior may change or even be removed +in any future release of perl. See the explanation under +L<perlsyn/Experimental Details on given and when>. =item Global symbol "%s" requires explicit package name (did you forget to declare "my %s"?) @@ -5711,12 +5717,20 @@ requested. hash) parameter. The slurpy parameter takes all the available arguments, so there can't be any left to fill later parameters. +=item Smart matching a non-overloaded object breaks encapsulation + +(F) You should not use the C<~~> operator on an object that does not +overload it: Perl refuses to use the object's underlying structure +for the smart match. + =item Smartmatch is experimental (S experimental::smartmatch) This warning is emitted if you use the smartmatch (C<~~>) operator. This is currently an experimental feature, and its details are subject to change in future releases of -Perl. +Perl. Particularly, its current behavior is noticed for being +unnecessarily complex and unintuitive, and is very likely to be +overhauled. =item Sorry, hash keys must be smaller than 2**31 bytes @@ -7488,17 +7502,13 @@ but in actual fact, you got So put in parentheses to say what you really mean. -=item whereis is experimental - -(S experimental::smartmatch) C<whereis> is experimental, and its behavior -may change or it may even be removed in any future release of perl. -See the explanation under L<perlsyn/Switch Statements>. - -=item whereso is experimental +=item when is experimental -(S experimental::smartmatch) C<whereso> is experimental, and its behavior -may change or it may even be removed in any future release of perl. -See the explanation under L<perlsyn/Switch Statements>. +(S experimental::smartmatch) C<when> depends on smartmatch, which is +experimental. Additionally, it has several special cases that may +not be immediately obvious, and their behavior may change or +even be removed in any future release of perl. See the explanation +under L<perlsyn/Experimental Details on given and when>. =item Wide character in %s |