Jos Backus
8/11/2006 1:34:00 AM
As part of a larger program I am trying to convert the following Perl code to
Ruby:
lizzy:~% cat ptest
sub equals {
my($a, $b) = @_;
return $a eq $b ? 1 : 0;
}
my $ops = {
'=' => sub { my ($a, $b) = @_; return $a eq $b ? 1 : 0; },
'==' => \&equals,
};
print $ops->{'='}(1, 1);
print $ops->{'=='}(1, 2);
lizzy:~% perl -l ptest
1
0
lizzy:~%
This is what I have come up with:
lizzy:~% cat rtest
OPS = {
'=' => proc { |a, b| return a == b ? 1 : 0 },
'==' => proc { |a, b| send(:equals, a, b) },
}
def equals(a, b)
return a == b ? 1 : 0
end
puts OPS['='].call(1, 1)
puts OPS['=='].call(1, 2)
lizzy:~% ruby rtest
1
0
lizzy:~%
But the `==' case is rather ugly. Is there a shorter way than saying `proc {
|a, b| send(:equals, a, b) }'? I.e. is there a way to avoid using the proc
wrapper?
I guess one the problems is that unlike in Python, parentheses are optional
Ruby. This means that `equals' returns what I am looking for in Python but in
Ruby it causes `equals' to be called. (In Python one has to use `equals()' to
actually perform the call).
Ideas, anybody?
Thanks,
--
Jos Backus
jos at catnook.com