Thanks for the historical perspective, puzzler! In addition to performance considerations, *Clojure Programming* points to an inconsistency between hash codes for longs and BigIntegers as a motivation.
Using the example number from that excellent book on Clojure 1.5.1 (on Java 8, FWIW), I can cause this: #{6948736584 (biginteger 6948736584)} ; => #{6948736584 6948736584} #{6948736584 (bigint 6948736584)} ; => IllegalArgumentException Duplicate key: 6948736584 clojure.lang.PersistentHashSet.createWithCheck (PersistentHashSet.java:56) (System/getProperty "java.version") ; => "1.8.0_05" (clojure-version) ; => "1.5.1" On Clojure 1.6, thankfully both fail, even in the face of the inconsistency between .hashCode implementations. If that essentially addresses the 2nd rationale for introducing a special BigInt class, maybe with both things being fixed with Java 8 and Clojure 1.6 BigInteger could come back as the sole arbitrary precision representation of ℤ. -- 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.