From: "Eregon (Benoit Daloze) via ruby-core" Date: 2023-03-15T11:15:28+00:00 Subject: [ruby-core:112897] [Ruby master Bug#4040] SystemStackError with Hash[*a] for Large _a_ Issue #4040 has been updated by Eregon (Benoit Daloze). My opinion as a TruffleRuby implementer is I don't TruffleRuby will or can support that. So at least it should be clear that's not something really supported by the Ruby language in general. User code shouldn't pass a million arguments, if it's say > 20 arguments or so one should pass an array, splatting on both sides is silly, it just creates extra copies and is slower. It's a Ruby anti-pattern. So IMO there is no point to fix or support this, such code doesn't make sense and changing the user code is the best fix, for performance and simplicity. ---------------------------------------- Bug #4040: SystemStackError with Hash[*a] for Large _a_ https://bugs.ruby-lang.org/issues/4040#change-102414 * Author: runpaint (Run Paint Run Run) * Status: Open * Priority: Normal * Assignee: ko1 (Koichi Sasada) * ruby -v: ruby 1.9.3dev (2010-11-09 trunk 29737) [x86_64-linux] * Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN ---------------------------------------- =begin I've been hesitating over whether to file a ticket about this, so please feel free to close if I've made the wrong choice. I often use Hash[*array.flatten] in IRB to convert arrays of arrays into hashes. Today I noticed that if the array is big enough, this would raise a SystemStackError. Puzzled, I looked deeper. I assumed I was hitting the maximum number of arguments a method's argc can hold, but realised that the minimum size of the array needed to trigger this exception differed depending on whether I used IRB or not. So, presumably this is indeed exhausting the stack... In IRB, the following is the minimal reproduction of this problem: Hash[*130648.times.map{ 1 }]; true I haven't looked for the minimum value needed with `ruby -e`, but the following reproduces: ruby -e 'Hash[*1380888.times.map{ 1 }]' I suppose this isn't technically a bug, but maybe it offers another argument for either #666 or an extension of #3131. =end -- https://bugs.ruby-lang.org/ ______________________________________________ ruby-core mailing list -- ruby-core@ml.ruby-lang.org To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/