From: marcandre-ruby-core@... Date: 2021-03-30T03:29:33+00:00 Subject: [ruby-core:103090] [Ruby master Bug#17737] `Array#permutation` does not immediately check the arity when no block is given Issue #17737 has been updated by marcandre (Marc-Andre Lafortune). I am not opposed to changes, but I don't believe this actually matters; I can not think of a use-case. A similar question could be asked of `[].permutation(:oops)`. Should it raise immediately? Asked another way, if the argument responds to `to_int`, should it be called immediately, or when iterated (or both)? The ideal is probably that argument checking and conversion be done exactly once and when the enumerator is created, but I don't think it would make a different in the real world. ---------------------------------------- Bug #17737: `Array#permutation` does not immediately check the arity when no block is given https://bugs.ruby-lang.org/issues/17737#change-91154 * Author: kachick (Kenichi Kamiya) * Status: Open * Priority: Normal * ruby -v: ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin20] * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN ---------------------------------------- ```ruby p [].permutation(1) #=> # p [].permutation(1, 3) #=> # p [].permutation(1, 3).to_a #=> `permutation': wrong number of arguments (given 2, expected 0..1) (ArgumentError) ``` ```ruby p [].cycle(1) #=> # p [].cycle(1, 3) #=> `cycle': wrong number of arguments (given 2, expected 0..1) (ArgumentError) ``` Is this an intentional behavior? I would expect `To raise ArgumentError immediately if the arity is wrong` like Array#cycle. PR: https://github.com/ruby/ruby/pull/4267 -- https://bugs.ruby-lang.org/ Unsubscribe: