# LISP to Ruby translation **URL:** \ **Category:** Ruby\ **Created:** [December 15, 2005, 3:36am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315 "2005-12-15T03:36:58Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 15, 2005, 3:36am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/1 "2005-12-15T03:36:58Z")
Jut a quick one, how do you translate this: ((if (zero? 0) + -) 3 4) =\> 7 to Ruby? Cheers, Douglas ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 15, 2005, 3:46am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/2 "2005-12-15T03:46:03Z")
Douglas L. wrote: > Jut a quick one, how do you translate this: > > ((if (zero? 0) + -) 3 4) > =\> 7 > > to Ruby? > > Cheers, > Douglas 3.send(x.zero? ? :+ : :-, 4) It’s a little hard to read with all those colons. Maybe this is better: 3.send(if x.zero? then :+ else :- end, 4) Or you could replace symbols with strings for readability, at a cost to speed: p 3.send(x.zero? ? “+” : “-”, 4) ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 15, 2005, 3:49am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/3 "2005-12-15T03:49:04Z")
Douglas L. wrote: > Jut a quick one, how do you translate this: > > ((if (zero? 0) + -) 3 4) > =\> 7 > > to Ruby? Well, these kind of questions are rarely helpful; translating an idiomatic expression out of context from one language is often useless, because in a greater context the ruby code might be doing something completely different to begin with. But, if you want a one-liner… 3.method(0.zero? ? :+ : :-).call(4) – Neil S. - removed\_email\_address@domain.invalid ‘A republic, if you can keep it.’ – Benjamin Franklin ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 15, 2005, 11:24pm UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/4 "2005-12-15T23:24:56Z")
Douglas L. wrote: > Just a quick one, how do you translate this: > > ((if (zero? 0) + -) 3 4) What dialect of LISP is that? Not Common… CL has no “zero?” (it’s “zerop”), and + and - refer to input history rather than the functions associated with the operators. To do something like that in CL I think you have to use the characters '+ and '- and an (eval)… ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 15, 2005, 11:40pm UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/5 "2005-12-15T23:40:07Z")
On Fri, Dec 16, 2005 at 07:22:39AM +0900, Mark J.Reed wrote: > Douglas L. wrote: > > > Just a quick one, how do you translate this: > > > > ((if (zero? 0) + -) 3 4) > > What dialect of LISP is that? Not Common… CL has no “zero?” It’s Scheme. A much nicer dialect than CL, IMHO. 😉 I think in CL the equivalent would be: ((if (zerop 0) #’+ #’-) 3 4) Note the ugly sharp-quotes, due to the fact that CL has separate namespaces for values and functions. regards, Ed ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 16, 2005, 8:27am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/6 "2005-12-16T08:27:37Z")
Stephen W. wrote: > –Steve 7 ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 16, 2005, 8:12am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/7 "2005-12-16T08:12:35Z")
On Dec 14, 2005, at 6:36 PM, Douglas L. wrote: > ((if (zero? 0) + -) 3 4) > =\> 7 > > to Ruby? 7 if true –Steve ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 17, 2005, 12:31am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/8 "2005-12-17T00:31:47Z")
Edward F. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes: > I think in CL the equivalent would be: > > ((if (zerop 0) #‘+ #’-) 3 4) No, you need: (apply (if (zerop 0) #‘+ #’-) '(3 4)) > Note the ugly sharp-quotes, due to the fact that CL has separate > namespaces for values and functions. And that is why. 🙂 ---
**Author:** ![dlewan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/eb9ed0/32.png) [@dlewan](https://www.ruby-forum.com/u/dlewan)\ **Post date:** [December 16, 2005, 11:04am UTC](https://www.ruby-forum.com/t/lisp-to-ruby-translation/50315/9 "2005-12-16T11:04:17Z")
Joel VanderWerf [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > 7 if true > > > > –Steve > > 7 There - who says ruby isn’t concise! martin