Ruby doesn't implement x++ for Fixnum's because ???
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From: David A. Black on 6 Nov 2009 15:49 Hi -- On Sat, 7 Nov 2009, Seebs wrote: > On 2009-11-06, David A. Black <dblack(a)rubypal.com> wrote: >> It seems like a lot of special-casing and strangeness, though. I'm a >> little bit hampered in discussing it, I guess, because I don't see >> what benefit it would confer in exchange for the anomaly. So I'm >> probably going in circles. > > I have found a lot of idioms which are amenable to use with ++, especially > postincrement, but they are often not nearly so useful outside of the C-like > languages. > > Consider the canonical inner loop for copying an array in C: > s[i++] = t[j++]; > > There's really no idiomatic equivalent -- nor a need for one, usually. Oh, I have no problem with ++ per se. It just seems against the grain in Ruby. David -- The Ruby training with D. Black, G. Brown, J.McAnally Compleat Jan 22-23, 2010, Tampa, FL Rubyist http://www.thecompleatrubyist.com David A. Black/Ruby Power and Light, LLC (http://www.rubypal.com)
From: Michael W. Ryder on 6 Nov 2009 16:24 Walton Hoops wrote: >> -----Original Message----- >> From: marnen(a)marnen.org [mailto:marnen(a)marnen.org] >>>> Now consider the ruby way: >>>> >>>> 10.times do |i| >>>> print "#{i}," >>>> end >>>> >>>> Some length as the C code, but much more readable. Heck, it's >>>> almost English! But if you wanted to do something like: i = 10; while (i > 0) { printf("%d/n", i--); } in Ruby you would have to do something like: i = 10 while (i > 0) puts i i -= 1 end As far as I can tell there is no way in Ruby to use .each or .times to go backwards. While I realize this thread is about the ++ operator the -- operator is complementary. <snip>
From: Marnen Laibow-Koser on 6 Nov 2009 16:34 Michael W. Ryder wrote: [...] > But if you wanted to do something like: > i = 10; > while (i > 0) > { > printf("%d/n", i--); > } > in Ruby you would have to do something like: > i = 10 > while (i > 0) > puts i > i -= 1 > end No. 10.downto(1) do |i| puts i end > As far as I can tell there is no way in Ruby to use .each or .times to > go backwards. That's what .downto is for. (Have you ever needed this? I have not.) > While I realize this thread is about the ++ operator the > -- operator is complementary. > > <snip> Best, -- Marnen Laibow-Koser http://www.marnen.org marnen(a)marnen.org -- Posted via http://www.ruby-forum.com/.
From: Matthew K. Williams on 6 Nov 2009 16:37 On Sat, 7 Nov 2009, Michael W. Ryder wrote: > Walton Hoops wrote: >>> -----Original Message----- >>> From: marnen(a)marnen.org [mailto:marnen(a)marnen.org] >>>>> Now consider the ruby way: >>>>> >>>>> 10.times do |i| >>>>> print "#{i}," >>>>> end >>>>> >>>>> Some length as the C code, but much more readable. Heck, it's >>>>> almost English! > > But if you wanted to do something like: > i = 10; > while (i > 0) > { > printf("%d/n", i--); > } > in Ruby you would have to do something like: > i = 10 > while (i > 0) > puts i > i -= 1 > end > As far as I can tell there is no way in Ruby to use .each or .times to go > backwards. While I realize this thread is about the ++ operator the -- > operator is complementary. > what about the downto method? Matt
From: David A. Black on 6 Nov 2009 16:41
Hi -- On Sat, 7 Nov 2009, Marnen Laibow-Koser wrote: > Michael W. Ryder wrote: > [...] >> But if you wanted to do something like: >> i = 10; >> while (i > 0) >> { >> printf("%d/n", i--); >> } >> in Ruby you would have to do something like: >> i = 10 >> while (i > 0) >> puts i >> i -= 1 >> end > > No. > > 10.downto(1) do |i| > puts i > end > >> As far as I can tell there is no way in Ruby to use .each or .times to >> go backwards. > > That's what .downto is for. (Have you ever needed this? I have not.) And in 1.9: puts *10.downto(1) and there's also #reverse_each. David -- The Ruby training with D. Black, G. Brown, J.McAnally Compleat Jan 22-23, 2010, Tampa, FL Rubyist http://www.thecompleatrubyist.com David A. Black/Ruby Power and Light, LLC (http://www.rubypal.com) |