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.
