It may not be idiomatic; or as concise; or as efficient; but there is no reason it cannot be readable.
It's just bigger, more lines of code. More characters in line. More scrolling needed.
if ($x && $s =~ /(abc|def)/)
is more readable than this
if ($x && index($s, "abc") >= 0 || index($s, "def") >= 0)
It is also a really strange claim. I mean, decently formatted C code is perfectly readable.
Good C code is readable. But good perl code more readable than good C code.
Do you perchance mean "isn't considered readable" by YOU?
Of course. Should I append "IMHO" to every my posting?
And if you are unfamiliar with Perl idioms; it is probably far more readable to you than idiomatic Perl.
And if you are familar only with Assembler idioms, Assembler is more readable than Perl, and even more, than C
without citing the source of authority
cpan grep for index