From: "mame (Yusuke Endoh)" Date: 2012-03-25T16:38:23+09:00 Subject: [ruby-core:43644] [ruby-trunk - Feature #4965][Assigned] The problem of "print line if line = DATA.gets" Issue #4965 has been updated by mame (Yusuke Endoh). Status changed from Open to Assigned Assignee set to matz (Yukihiro Matsumoto) ---------------------------------------- Feature #4965: The problem of "print line if line = DATA.gets" https://bugs.ruby-lang.org/issues/4965#change-25144 Author: yimutang (Joey Zhou) Status: Assigned Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: Target version: Right now, I find the following code will raise an exception: print line if line = DATA.gets __END__ abcdef # undefined local variable or method `line' for main:Object (NameError) "print line while line = DATA.gets" also doesn't work, maybe "unless" "until" modifiers either. It seems that the Ruby interpreter is too impatient, once seeing unassigned variable "line", it croaks. However, the expression after "if" or "while" modifier should be evaluated first. Logically, I think the code above should work properly, there's no need to write "line = nil" before it. -- http://bugs.ruby-lang.org/