From: dazuma@... Date: 2021-01-04T06:40:33+00:00 Subject: [ruby-core:101903] [Ruby master Feature#10499] Eliminate implicit magic in Proc.new and Kernel#proc Issue #10499 has been updated by dazuma (Daniel Azuma). Note that the documentation still specifies the old behavior in 3.0.0. > Creates a new Proc object, bound to the current context. ::new may be called without a block only within a method with an attached block, in which case that block is converted to the Proc object. https://ruby-doc.org/core-3.0.0/Proc.html#method-c-new https://github.com/ruby/ruby/blob/95aff214687a5e12c3eb57d056665741e734c188/proc.c#L800-L813 ---------------------------------------- Feature #10499: Eliminate implicit magic in Proc.new and Kernel#proc https://bugs.ruby-lang.org/issues/10499#change-89745 * Author: headius (Charles Nutter) * Status: Open * Priority: Normal * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- Proc.new and Kernel#proc have a little known feature: if called without a block, they capture whatever block was passed to the current method. I propose that this feature should be removed, finally, since it: * Doesn't enhance readability (where is this block coming from?) * Doesn't reflect any other behavior in Ruby * Can lead to bugs (call either without a block accidentally and you aren't sure what you'll get) I believe this was an implementation artifact in MRI, since the most recently-pushed block would still be on global stacks, which is where the logic for proc and Proc.new looked for it. All argument syntaxes now support &block, which I believe is the correct way to clearly, explicitly capture the incoming block into an object. Thoughts? -- https://bugs.ruby-lang.org/ Unsubscribe: