I'm mildly surprised the article doesn't mention that Perl, one of the languages that influenced Ruby, also has unless.
Read this post ‘unless’ you’re not a Ruby developer
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Re: Read this post ‘unless’ you’re not a Ruby developer
#12I've written ruby everyday for the past 5 years. I still cannot read an unless statement and understand it first time. Most of the time i'm translating it to `if !` anyway.
Re: Read this post ‘unless’ you’re not a Ruby developer
#13The worst thing about `unless` and double negatives, is having been raised in a culture with different double negative rules than English. In Italian a double negative is still negative. I know boolean logic pretty well, but `unless !something` still trips me up to this day.
There are two different kinds of double negatives and English actually has both.
E.g. `I can't get no satisfaction` is structurally equivalent to French `ne ... pas`, i.e the second `no` is a reaffirmation, not a negation.
On the other hand `read this unless you're not a developer` is a logical double negation and thus equivalent to `read this if you're a developer`. In practice of course there are usually implied subtleties that make the two not entirely equivalent (the same way synonyms are conceptually interchangeable but may carry different subtext).
EDIT: I can't actually think of any true "double negative" in English that isn't indirect (e.g. `indirect` being synonymous with `not direct` thus `not indirect` being synonymous with `not not direct` and `not not` cancelling itself out). The only direct forms I can think of behave like `not ... no` in my first example, i.e. re-affirmations of the negative rather than double negations.
I think most of the complaints about "double negatives" (where the Rolling Stones line is usually cited as an example) are stylistic preferences or intentional misunderstandings based on arbitrary prescriptions (which are usually based in other languages like Latin that are perceived as "purer" or "more sophisticated").
Re: Read this post ‘unless’ you’re not a Ruby developer
#14I don't have a problem with double negation but I hate ruby for this kind of design - pointless aliases for everything. It's the exact opposite of pythons "There should be one– and preferably only one –obvious way to do it" - they intentionally create solutions that have zero practical benefit - it's just fuels arguments based on preferences and introduces mental overhead due to inconsistency.
In Perl I once saw someone write;
unless predicate
do this
else unless impossible_thing
do the impossible
Re: Read this post ‘unless’ you’re not a Ruby developer
#15I don't have a problem with double negation but I hate ruby for this kind of design - pointless aliases for everything. It's the exact opposite of pythons "There should be one– and preferably only one –obvious way to do it" - they intentionally create solutions that have zero practical benefit - it's just fuels arguments based on preferences and introduces mental overhead due to inconsistency.
To be fair, Ruby inherited "unless" from Perl.
And Perl literally has the opposite design principle, TIMTOWTDI or "there is more than one way to do it".
I'm not arguing here -- I prefer the "one obvious way" principle.
But you can design a beautiful programming language without regard for the long-term learnings of software engineering.
I always liked Perl's "unless", and I always made sure to not abuse it with double negatives or other contorted conditions that are, in themselves, reasonable. I also promised myself I wouldn't write very big programs in Perl.
Re: Read this post ‘unless’ you’re not a Ruby developer
#16I'm mildly surprised the article doesn't mention that Perl, one of the languages that influenced Ruby, also has unless.
Those who don't know history are doomed to repeat it. ;-)
Re: Read this post ‘unless’ you’re not a Ruby developer
#17The visual difference between a ! and an l is not that great, send_email if !user.suspended? or send_email if luser.suspended? The latter could easily be an aggressive dev sending abusive emails to users they dislike enough to call lusers, at first glance at least ...
Brought back memories of alt.sysadmin.recovery.
Re: Read this post ‘unless’ you’re not a Ruby developer
#18The worst thing about `unless` and double negatives, is having been raised in a culture with different double negative rules than English. In Italian a double negative is still negative. I know boolean logic pretty well, but `unless !something` still trips me up to this day.
Ain't nobody got time for that!
Re: Read this post ‘unless’ you’re not a Ruby developer
#19Earlier quoted context omitted.
I’m one of those weirdos who can inline a double negative instantly so, I didn’t read it yet but I probably will because I’m curious about the title anyway
Oh my dear lord I didn’t think I’d actually disagree with the f’ing article but I had like 8 cases today that made me wish I had a built in if-not keyword! I mean, every language with the billion dollar mistake probably needs a language feature designed to pay back some of that.
I think the author would probably be fine with an if-not. It doesn't hide the double negation like unless.
Re: Read this post ‘unless’ you’re not a Ruby developer
#20I'm currently writing assembler for a virtual machine that has a "skiz" instruction.
It means "skip if zero".
The double negative always trips me up.
I had to write "don't skip if not zero" next to it the first dozen or so times.