4 ms·

I would say that the phrase "Yoda conditions" more appropriately describes Ruby's alternative form of if-statements: if x > 0: y += x versus

• kentt 10y ago
  One of the worst parts of Ruby. I can see the argument that it could be better to have save if valid rather than if valid save end but what I see 9 times out of 10 is things.do each |thing| foo bar baz end if valid or really.long.thing.that.i.try.to.parse.in.my.head if acutally_almost_never_happens which is harder to read since I read top to bottom / left to right, but the flow is bottom to top and right to left
  • Gaelan 10y ago
    You can write gibberish in any language. You shouldn't kill useful features because they are sometimes misused.
    • olalonde 10y ago
      > You shouldn't kill useful features because they are sometimes misused. That is highly debatable.
    • ghurtado 10y ago
      Not even PHP's "register_globals"?
      • Gaelan 10y ago
        I'd argue that register_globals is never a good idea. Post-if is sometimes a good idea, with one case that is problematic (less readable, not even a negative affect on function)
        • ghurtado 10y ago
          I happen to agree, but the statement was about "useful features".
  • kbenson 10y ago
    This is something Ruby likely got form Perl,but they cribbed it wrong. Perl's post-conditionals only work on single statements, not blocks. You can use them for functional style statements though. I.e. # Not allowed for ( 1 .. 10 ) { say $_; } if 1; # Allowed map { say $_ } ( 1 .. 10 ) if 1; The idea seems to be that a post-conditional should be simple and obvious by the time you've parsed the statement. A block makes it confusing, as does mixing post control structures Post-loop structures have the same limitation: # Not allowed { say "foo"; say $_ } for ( 1 .. 10 ); # Allowed say $_ for ( 1 .. 10 ); When used correctly, these can become very succinct and clear. my %data = get_data_record_hash("foo"); $data{$_} = update_field(data{$_}) for ('field1','field4',other_field'); # Compare to map, which normally you expect to return values map { $data{$_} = update_field(data{$_}) } ('field1','field4',other_field'); The single statement limitation keeps you from going wild in ways that are probably not useful to future readers of the code (including you).
• yellowapple 10y ago
  To clarify a bit: postfix conditionals actually originate from Perl, and are one of several things that Ruby inherited as a Perl descendant. In Perl: if ($x > 0) { $y += $x } versus: $y += $x if $x > 0;