Provided by: libperl-critic-pulp-perl_99-1_all 
NAME
Perl::Critic::Policy::CodeLayout::RequireFinalSemicolon - require a semicolon at the end of code blocks
DESCRIPTION
This policy is part of the "Perl::Critic::Pulp" add-on. It asks you to put a semicolon ";" on the final
statement of a subroutine or block.
sub foo {
do_something(); # ok
}
sub bar {
do_something() # bad
}
The idea is that if you add more code you don't have to notice the previous line needs a terminator.
It's also more like the C language, if you consider that a virtue.
This is only a matter of style since the code runs the same either way, and on that basis this policy is
low severity and under the "cosmetic" theme (see "POLICY THEMES" in Perl::Critic).
Same Line Closing Brace
By default (see "CONFIGURATION" below), a semicolon is not required when the closing brace is on the same
line as the last statement. This is good for constants and one-liners.
sub foo { 'my-constant-value' } # ok
sub square { return $_[0] ** 2 } # ok
Final Value Expression
A semicolon is not required in places where the last statement is an expression giving a value.
map { some_thing();
$_+123 # ok
} @values;
do {
foo();
1+2+3 # ok
}
This currently means
do grep map sort # builtins
reduce any all none notall first # List::Util
pairfirst pairgrep pairmap
mapp map_pairwise grepp grep_pairwise # List::Pairwise
firstp first_pairwise lastp last_pairwise
These module function names are always treated as expressions. There's no check for whether the
respective module is actually in use. Fully qualified names like "List::Util::first" are recognised too.
"do {} while" or "do {} until" loops are ordinary blocks, not expression blocks, so still require a
semicolon on the last statement inside.
do {
foo() # bad
} until ($condition);
Try/Catch Blocks
The "Try", "TryCatch" and "Syntax::Feature::Try" modules all add "try" block forms. These are blocks not
requiring a terminating semicolon, the same as an "if" etc doesn't.
use TryCatch;
sub foo {
try {
attempt_something();
} catch {
error_recovery();
} # ok, no semi required here for TryCatch
}
The insides of the "try" and "catch" are the same as other blocks, but the "try" statement itself doesn't
require a semicolon. (See policy "ValuesAndExpressions::ProhibitNullStatements" to notice one added
unnecessarily.)
For reference, "PPI" doesn't know "try"/"catch" specifically, so when they don't have a final semicolon
the next statement runs together and the nature of those parts might be lost. This could upset things
like recognition of "for" loops and could potentially make some perlcritic reports go wrong.
The "try"/"catch" block exemption here is only for the modules with this block syntax. There are other
try modules such as "Try::Tiny" and friends where a final semicolon is normal and necessary if more code
follows (because their "try" and "catch" are ordinary function calls prototyped to take code blocks).
use Try::Tiny;
sub foo {
try {
attempt_something();
} catch {
error_recovery();
} # bad, semi required here for Try::Tiny
}
Disabling
If you don't care about this you can always disable from your .perlcriticrc file in the usual way (see
"CONFIGURATION" in Perl::Critic),
[-CodeLayout::RequireFinalSemicolon]
CONFIGURATION
"except_same_line" (boolean, default true)
If true (the default) then don't demand a semicolon if the closing brace is on the same line as the
final statement.
sub foo { return 123 } # ok if "except_same_line=yes"
# bad if "except_same_line=no"
"except_expression_blocks" (boolean, default true)
If true (the default) then don't demand a semicolon at the end of an expression block, as described
under "Final Value Expression" above.
# ok under "except_expression_blocks=yes"
# bad under "except_expression_blocks=no"
do { 1+2+3 }
map { $_+1 } @array
grep {defined} @x
The statements and functions for this exception are currently hard coded. Maybe in the future they
could be configurable, though multi-line expressions in this sort of thing tends to be unusual
anyway. (See policy "BuiltinFunctions::RequireSimpleSortBlock" for example to demand "sort" is only
one line.)
BUGS
It's very difficult to distinguish a code block from an anonymous hashref constructor if there might be a
function prototype in force, eg.
foo { abc => 123 }; # hash ref normally
# code block if foo() has prototype
"PPI" tends to assume code. "RequireFinalSemicolon" currently assumes hashref so as to avoid false
violations. Any "try", "catch" or "finally" are presumed to be code blocks (the various Try modules).
Perhaps other common or particular functions or syntax with code blocks could be recognised. In general
this sort of ambiguity is another good reason to avoid function prototypes.
PPI as of its version 1.270 sometimes takes hashrefs in lists and arrarefs to be code blocks, eg.
ppidump 'foo({%y,x=>1})'
ppidump '[{%y,x=>1}]'
ppidump '[{x=>1,%y}]' # ok, hash
SEE ALSO
Perl::Critic::Pulp, Perl::Critic, Perl::Critic::Policy::CodeLayout::RequireTrailingCommas,
Perl::Critic::Policy::CodeLayout::RequireTrailingCommaAtNewline,
Perl::Critic::Policy::Subroutines::RequireFinalReturn,
Perl::Critic::Policy::ValuesAndExpressions::ProhibitNullStatements,
Perl::Critic::Policy::BuiltinFunctions::RequireSimpleSortBlock
List::Util, List::Pairwise, Try, TryCatch, Syntax::Feature::Try
HOME PAGE
<http://user42.tuxfamily.org/perl-critic-pulp/index.html>
COPYRIGHT
Copyright 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019, 2021 Kevin Ryde
Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the terms of the GNU
General Public License as published by the Free Software Foundation; either version 3, or (at your
option) any later version.
Perl-Critic-Pulp is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
You should have received a copy of the GNU General Public License along with Perl-Critic-Pulp. If not,
see <http://www.gnu.org/licenses>.
perl v5.32.1 2021-02-28 Perl::Critic::...eFinalSemicolon(3pm)