Semi-related anecdote: Ruby enforces commas in arrays but the problem still exists for [f 1, 2]. Is it [(f 1), 2] or [f(1, 2)]? Apparently as a consequence of

Semi-related anecdote: Ruby enforces commas in arrays but the problem still exists for [f 1, 2]. Is it [(f 1), 2] or [f(1, 2)]? Apparently as a consequence of this ambiguity, even [f 1] has become illegal in Ruby 1.9. One of those god-awful undocumented changes that broke my apps. :(