More elegant way to test for numeric scalars

Now we can also dump floats without quoting.

lib/Data/Dump.pm

@@ -232,14 +232,8 @@ sub _dump
 	    if (!defined $$rval) {
 		$out = "undef";
 	    }
-	    elsif (my $v = substr($$rval, 0, 12), $$rval =~ /^-?[1-9]\d{0,9}\z/ || $$rval eq "0") {
-		# The assignment to $v above is required because the fact that we use
-		# a regexp here will actually modify $$rval if it happens to be an alias
-		# for one of the regexp special vars, like $1.  We use substr instead of
-		# regular stringification, just to make it cheaper in case the scalar
-		# we're dumping is huge.  The prefix length extracted must be longer
-		# than what the regexp might match for this code to be correct.
-		$out = $v;
+	    elsif (do {no warnings 'numeric'; $$rval + 0 eq $$rval}) {
+		$out = $$rval;
 	    }
 	    else {
 		$out = str($$rval);

t/dump.t

@@ -2,7 +2,7 @@
 
 use strict;
 use Test qw(plan ok);
-plan tests => 30;
+plan tests => 33;
 
 use Data::Dump qw(dump);
 
@@ -14,8 +14,11 @@ ok(dump(0), "0");
 ok(dump(1234), "1234");
 ok(dump(12345), "12345");
 ok(dump(12345678), "12345678");
+ok(dump(123456789012345), "123456789012345");
+ok(dump(0.333), "0.333");
+ok(dump(1/3), qr/^0\.3+\z/);
 ok(dump(-33), "-33");
-ok(dump(-1.5), "\"-1.5\"");
+ok(dump(-1.5), "-1.5");
 ok(dump("0123"), qq("0123"));
 ok(dump(1..2), "(1, 2)");
 ok(dump(1..3), "(1, 2, 3)");