Bug #6723

Global variable scoping problem.

Added by Markus Fenske almost 2 years ago. Updated over 1 year ago.

[ruby-core:46335]
Status:Closed
Priority:Normal
Assignee:Eric Hodel
Category:doc
Target version:2.0.0
ruby -v:- Backport:

Description

This issue exists from 1.8 to ruby-head.

See the following example:

def foobar
"Foobar".match(/\*)/)
puts $1.inspect
end

foobar
puts $1.inspect
puts global_variables.inspect

This demonstrates that $1 does not behave like a global variable. However it's listed by Kernel.global_variables as a global variable. And it's named like a global variable.

This leads to some confusion sometimes. See for example http://stackoverflow.com/q/11441782/773690

It may not be a good idea to fix this inconsistent naming, because it may break severaly things. However the fact that $1 and friends are not global variables should be clearly documented. And by the way: Ruby != Perl.

Or maybe make $1 a real global variable?

Associated revisions

Revision 36526
Added by Eric Hodel over 1 year ago

  • re.c (rbregslastmatch): Update $~ to reference Regexp documentation about "special global variables". [Bug #6723]

History

#1 Updated by Koichi Sasada almost 2 years ago

  • Target version set to 2.0.0
  • Category set to core
  • Assignee set to Yukihiro Matsumoto

#2 Updated by Nobuyoshi Nakada almost 2 years ago

  • Category changed from core to doc
  • Status changed from Open to Assigned
  • Assignee changed from Yukihiro Matsumoto to Eric Hodel
  • ruby -v changed from ruby 1.9.3p194 to -

#3 Updated by Eric Hodel over 1 year ago

  • Status changed from Assigned to Closed
  • % Done changed from 0 to 100

This issue was solved with changeset r36526.
Markus, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.


  • re.c (rbregslastmatch): Update $~ to reference Regexp documentation about "special global variables". [Bug #6723]

#4 Updated by Eric Hodel over 1 year ago

These are described as "Special global variables" and are described as "thread-local and method-local" in the Regexp documentation. I updated a reference to them in re.c, but the existing documentation should be sufficient.

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