Provided by: libperl-critic-pulp-perl_96-1_all

#### NAME

Perl::Critic::Policy::Documentation::ProhibitUnbalancedParens - don't leave an open
bracket or paren

#### DESCRIPTION

This policy is part of the "Perl::Critic::Pulp" add-on.  It reports unbalanced or
mismatched parentheses, brackets and braces in POD text paragraphs,

Blah blah (and something.    # bad

Blah blah ( [ ).             # bad

Blah blah brace }.           # bad

This is only cosmetic and normally only a minor irritant to readability so this policy is
low severity and under the "cosmetic" theme (see "POLICY THEMES" in Perl::Critic).

Text and command paragraphs are checked, but verbatim paragraphs can have anything.  There
are some exceptions to paren balancing.  The intention is to be forgiving of common or
reasonable constructs.  Currently this means,

·   Anything in "C<>" code markup is ignored

In code C<anything [ is allowed>.  # ok

Perhaps this will change, though there'd have to be extra exceptions in "C<>", such as
various backslashing.

Sometimes a prematurely ending "C<>" may look like an unbalanced paren, for example

This is bad because the "C<>" ends at the "=>", leaving "value)" unbalanced plain
text.  This is an easy mistake to make.  (The author's "perl-pod-gt.el" can show
warning face on this in Emacs.)

·   Quoted "(" is taken to be describing the char and is not an open or close.

Any of "(" or '[' or "[{]".   # ok

This only applies to quoted parens alone (one or more), not larger quoted text.

·   Item parens

a) the first thing, or b) the second thing   # ok

1) one, 2) two     # ok

Exactly how much is recognised as an "a)" etc is not quite settled.  In the current
code a "1.5)" is recognised at the start of a paragraph, but in the middle only "1)"
style.

·   Smiley faces are an "optional" close,

(Some thing :-).                # ok

Bare smiley :).                 # ok

(Or smile :-) and also close.)  # ok

·   Sad smiley faces are not an opening paren,

:( :-(.     # ok

·   Perl variables $( and$[ are not opening parens,

Default is group $( blah blah. # ok${ brace is still an open and expected to have a matching close, because it's likely
to be a deref or delimiter,

Deref with ${foo()} etc etc. Variables or expressions like this will often be in "C<>" markup and skipped for that reason instead, as described above. ·$) and $] are optional closes, since they might be Perl variables to skip, or might be "$" at the end of a parens,

blah blah (which in TeX is $1\cdot2$).

Perhaps the conditions for these will be restricted a bit, though again "C<>" markup
around sample code like this will be usual.

(POD document name and section) can have anything.

"=begin :foo" ... "=end :foo" sections with a format name ":foo" starting with a ":" are
POD markup and are processed accordingly.  Other "=begin" sections are skipped.

Unrecognised Forms
A mathematical half-open range like the following is not recognised.

Perhaps just numbers like this would be unambiguous, but if it's an expression then it's
hard to distinguish a parens typo from some mathematics.  The suggestion for now is an
"=for" per below to flag it as an exception.  Another way would be to write 1 <= X < 2,
which might be clearer to mathematically unsophisticated readers.

Parens spanning multiple paragraphs are not recognised,

Hopefully this is uncommon, and probably better style not to be parenthetical about
something so big that it runs to multiple paragraphs or has a verbatim block in the middle
etc.

Disabling
If an unbalanced paren is intended you can add an "=for" to tell
"ProhibitUnbalancedParens" to allow it.

=for ProhibitUnbalancedParens allow next

Something ( deliberately unclosed.

Or with a count of paragraphs to ignore,

=for ProhibitUnbalancedParens allow next 2

First deliberate [ unclosed.

Second (.

The usual no critic

## no critic (ProhibitUnbalancedParens)

works too as a whole-file disable, but the annotation must be before any "__END__" token,
and if the POD is after the "__END__" then "Perl::Critic" 1.112 up is required.
Individual "=for" has the advantage of being with an exception.

completely from your .perlcriticrc in the usual way (see "CONFIGURATION" in Perl::Critic),

[-Documentation::ProhibitUnbalancedParens]

#### SEEALSO

Perl::Critic::Pulp, Perl::Critic

<http://user42.tuxfamily.org/perl-pod-gt/index.html>

#### HOMEPAGE

http://user42.tuxfamily.org/perl-critic-pulp/index.html

Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017 Kevin Ryde

Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the