"It is out of scope for Clojure to fix this for Java types Float/Double" -- comments in CLJ-1036: http://dev.clojure.org/jira/browse/CLJ-1036
Andy On Thu, Jan 22, 2015 at 5:53 AM, Nicola Mometto <brobro...@gmail.com> wrote: > > Not sure if this is intended behaviour: > user=> (= (float 1.6) (double 1.6)) > false > user=> (= (float 1.5) (double 1.5)) > true > > I.e. = (and ==) will return true when comparing floats with doubles IFF > the float's .doubleValue roundtrips to the same double it's comparing to. > > user=> (.doubleValue (float 1.6)) > 1.600000023841858 > user=> (.doubleValue (float 1.5)) > 1.5 > > I'm not sure why floats are not handled specially in Numbers.java so > that hash/comparision is handled consistently with doubles (e.g. by > converting the floats to the fitting double via Double.parseDouble), > the current behaviour seems odd to me. > > Jozef Wagner writes: > > > More on this behavior http://dev.clojure.org/jira/browse/CLJ-1036 > > > > On Thu, Jan 22, 2015 at 2:00 PM, Nicola Mometto <brobro...@gmail.com> > wrote: > > > >> > >> Looking at the PHM impl, this looks like it's caused by (float 0.5) and > >> (double 0.5) hashing differently. > >> > >> user=> (= (float 0.5) (double 0.5)) > >> true > >> user=> (map hash [(float 0.5) (double 0.5)]) > >> (1056964608 1071644672) > >> > >> Nicola Mometto writes: > >> > >> > Looks like it's a bug in PersistentHashMap: > >> > user=> (contains? (hash-map {:a (float 0.5)} 1) {:a (double 0.5)}) > >> > false > >> > user=> (contains? (array-map {:a (float 0.5)} 1) {:a (double 0.5)}) > >> > true > >> > > >> > Immo Heikkinen writes: > >> > > >> >> (= (float 0.5) (double 0.5)) > >> >> => true > >> >> (= #{(float 0.5)} #{(double 0.5)}) > >> >> => true > >> >> (= {:a (float 0.5)} {:a (double 0.5)}) > >> >> => true > >> >> (= #{{:a (float 0.5)}} #{{:a (double 0.5)}}) > >> >> => false > >> >> > >> >> > >> >> Tested with both 1.6.0 and 1.7.0-alpha5. > >> > >> -- > >> > >> -- > >> You received this message because you are subscribed to the Google > >> Groups "Clojure" group. > >> To post to this group, send email to clojure@googlegroups.com > >> Note that posts from new members are moderated - please be patient with > >> your first post. > >> To unsubscribe from this group, send email to > >> clojure+unsubscr...@googlegroups.com > >> For more options, visit this group at > >> http://groups.google.com/group/clojure?hl=en > >> --- > >> You received this message because you are subscribed to the Google > Groups > >> "Clojure" group. > >> To unsubscribe from this group and stop receiving emails from it, send > an > >> email to clojure+unsubscr...@googlegroups.com. > >> For more options, visit https://groups.google.com/d/optout. > >> > > -- > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
