No engine interns computed strings unconditionally. Consider concatenated strings, the silly benchmarks that s += s for s = "x" up to 20 or more times.
Engines do optimize string comparison to compare pointers first, in case both comparands are interned. Engines also know when a string is interned so they can optimize accordingly. Engines also intern small int literal strings, e.g. /be On Oct 3, 2011, at 6:28 PM, Allen Wirfs-Brock wrote: > > On Oct 3, 2011, at 10:17 AM, David Herman wrote: > >> A couple reactions: >> >> - strings are already interned in current engines for symbol-like >> performance; there's no need to introduce symbols into the language > > Is this really true? It was my original assumption based upon string > semantics. However, I was latter lead to believe that many engines don't > routinely intern/canonicalize strings and hence string equality comparisons > can't be assume to have the performance of pointer comparisons. For > example, it was my understanding that SpiderMonkey uses interned strings for > property lookup but that it doesn't necessarily intern non-property key > strings?? > > > Allen > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
