From: shevegen@... Date: 2017-09-25T18:15:36+00:00 Subject: [ruby-core:83004] [Ruby trunk Bug#13939] Ruby 2.4.2 has issue supporting Seattle.rb style for define_method Issue #13939 has been updated by shevegen (Robert A. Heiler). Let's ignore the "Seattle.rb style" for the moment because I don't know of such a thing - may well be seattle-duck style. :P But anyway, I agree with you in at the least one point, which is the warning message: > Anyone who tries to load my 'read_source' gem will get a failure message > in require without explaining the specific area of code. Perhaps the error message could be more indicative of the error or what the exact problem is or how to solve it. I understand that the () provide additional information that is in some way useful to the parser, or whatever is responsible, so perhaps the message above could be changed somewhat. I guess ruby core prefers short messages when possible (aka "syntax error, unexpected '}'") but this is indeed not always extremely helpful. With more recent changes such as the did-you-mean-gem, but also some other discussions about better and more fine-tuned control over warnings/error messages, that may be helpul. To the issue about differential parsing, that is actually indeed strange. Even more surprising is that I actually thought that: define_method(:some_method_name) { "asdf" } Is the only way to use define_method() :D I think I used that always ... It reminds me a bit of: get '/' do play_intro_music end versus get '/' { play_intro_music } # which does not work versus get('/') { play_intro_music } which works. I always thought that in some cases the ruby parse needs the (). I'd love to be able to make them optional in the second case. Oddly enough, for method DEFINITIONS, I always use () when there are arguments, so "def foo(bar)" is what I prefer over "def foo bar". This is more an aside though, it is strange that this changed. By the way your last example does not work as-is :D define_method :johny, instance_method(:apple) NoMethodError: undefined method `instance_method' for main:Object Sorry for nitpicking there, I understand what you mean. I guess it may be because of {} having different meanings in ruby but then again, there was probably some reason unless it was an accident. It's ~3:15 in Tokyo so I guess in a few hours perhaps some from the ruby core team can chime in. I did not even know that we could omit the () there, that was awesome if that was possible. I remember in my code though, that whenever I used define_method(), I always used () ... usually in combination with some *eval* method thing. ---------------------------------------- Bug #13939: Ruby 2.4.2 has issue supporting Seattle.rb style for define_method https://bugs.ruby-lang.org/issues/13939#change-66913 * Author: danielpclark (Daniel P. Clark) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-linux] * Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN ---------------------------------------- In Ruby 2.3 & 2.4.0 you can do this ~~~ruby define_method :some_method_name { "asdf" } ~~~ As of my trying 2.4.2 this is no longer supported. Anyone who tries to load my 'read_source' gem will get a failure message in require without explaining the specific area of code. ~~~ SyntaxError: /home/danielpclark/dev/read_source/test/support/example.rb:18: syntax error, unexpected '{', expecting keyword_end ethod :also_attr_method_name { "asdf" } ^ /home/danielpclark/dev/read_source/test/support/example.rb:18: syntax error, unexpected '}', expecting keyword_end so_attr_method_name { "asdf" } ^ from (irb):2:in `require_relative' from (irb):2 from /usr/share/rvm/rubies/ruby-2.4.2/bin/irb:11:in `
' ~~~ To fix my gem for Ruby 2.4.2 I now have to wrap the method name in parenthesis `()` ~~~ruby define_method(:some_method_name) { "asdf" } ~~~ And that will work. But I find this odd as the following will still work in 2.4.2: ~~~ruby define_method :johny, instance_method(:apple) ~~~ Which is still Seattle.rb style. -- https://bugs.ruby-lang.org/ Unsubscribe: