$ perl -wE 'say "fred" -> can ("can")'
Use of uninitialized value in say at -e line 1.
$ perl -wE 'say "1fred" -> can ("can")'
Can't call method "can" without a package or object reference at -e line 1.
$ perl -wE 'say " " -> can ("can")'
Can't call method "can" without a package or object reference at -e line 1.
$ perl -wE 'say "f r e d" -> can ("can")'
Use of uninitialized value in say at -e line 1.
$