[ilmari@ilmari.org]

Hi hackers,

In the patches for improving the MSVC build process, I noticed a use of
`map` in void context.  This is considered bad form, and has a
perlcritic policy forbidding it:
https://metacpan.org/pod/Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidMap.

Attached is a patch that increases severity of that and the
corresponding `grep` policy to 5 to enable it in our perlcritic policy,
and fixes the one use that had already snuck in.

- ilmari

Attachments:

0001-perlcritic-prohibit-map-and-grep-in-void-context.patch (text/x-diff, 1.3K) download
From c82b08ce047ab47188753806984f1dc5be365556 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dagfinn=20Ilmari=20Manns=C3=A5ker?= <ilmari@ilmari.org>
Date: Tue, 27 Jul 2021 16:51:29 +0100
Subject: [PATCH] perlcritic: prohibit map and grep in void context

---
 contrib/intarray/bench/create_test.pl | 2 +-
 src/tools/perlcheck/perlcriticrc      | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/contrib/intarray/bench/create_test.pl b/contrib/intarray/bench/create_test.pl
index 993a4572f4..ae8d72bab0 100755
--- a/contrib/intarray/bench/create_test.pl
+++ b/contrib/intarray/bench/create_test.pl
@@ -51,7 +51,7 @@
 	else
 	{
 		print $msg "$i\t{" . join(',', @sect) . "}\n";
-		map { print $map "$i\t$_\n" } @sect;
+		print $map "$i\t$_\n" foreach @sect;
 	}
 }
 close $map;
diff --git a/src/tools/perlcheck/perlcriticrc b/src/tools/perlcheck/perlcriticrc
index e230111b23..9267fb43b2 100644
--- a/src/tools/perlcheck/perlcriticrc
+++ b/src/tools/perlcheck/perlcriticrc
@@ -22,3 +22,10 @@ verbose = %f: %m at line %l, column %c.  %e.  ([%p] Severity: %s)\n
 # insist on use of the warnings pragma
 [TestingAndDebugging::RequireUseWarnings]
 severity = 5
+
+# forbid grep and map in void context
+[BuiltinFunctions::ProhibitVoidGrep]
+severity = 5
+
+[BuiltinFunctions::ProhibitVoidMap]
+severity = 5
-- 
2.30.2