[sqlite] Should Unary + Cast to a Number?

[David Wheeler]

Hi All,
Given the below script (using DBD::SQLite 1.08, which uses SQLite 
3.1.3), the output is just:

  +0 Cast: 2005-03-22T00:00:00
I'm wondering, however, if unary + shouldn't also be able to cast an 
expression to a number...shouldn't it?

Thanks,
David
#!/usr/bin/perl -w
use strict;
use DBI;
use constant SQLITE_FILE => shift;
my $dbh = DBI->connect_cached(
    'dbi:SQLite:dbname=' . SQLITE_FILE, '', '', {
        RaiseError  => 1,
        PrintError  => 0,
    }
);
END {
    $dbh->disconnect;
    $dbh->rollback;
}
$dbh->begin_work;
$dbh->do("CREATE TABLE foo (a TEXT)");
$dbh->do("INSERT INTO foo VALUES('2005-03-22T00:00:00')");
my $sth = $dbh->prepare("SELECT * FROM foo WHERE (substr(a, 6, 2) = 
?)");
$sth->execute('03');
while (my $row = $sth->fetchrow_arrayref) {
    print "No Cast: $row->[0]\n";
}

$sth = $dbh->prepare("SELECT * FROM foo WHERE (+substr(a, 6, 2) = ?)");
$sth->execute('03');
while (my $row = $sth->fetchrow_arrayref) {
    print "Unary Cast: $row->[0]\n";
}
$sth = $dbh->prepare("SELECT * FROM foo WHERE (substr(a, 6, 2)+0 = ?)");
$sth->execute('03');
while (my $row = $sth->fetchrow_arrayref) {
    print "+0 Cast: $row->[0]\n";
}