Bug #8205

Regexp.union behavior and Regexp.try_convert

Added by avyy (Alexander Yunin) over 7 years ago. Updated almost 7 years ago.

Target version:
ruby -v:


Hi! Why Regexp.union('/../') trying to convert string with directly call rb_check_regexp_type(arg) (re.c:3139) instead of rb_reg_s_try_convert (re.c:3122)? I think second variant would be more correct, and i would be able to rewrite Regexp.try_convert in my code for changing behavior as i need.
For example: i have the code where was implemented String#to_regexp which breaks default behavior of Regexp.union and i got incorrect regexp. But i can't (for some reasons) to rewrite to_regexp method. Yes, stupid example, but it's real situation.

Updated by nagachika (Tomoyuki Chikanaga) about 7 years ago

  • Status changed from Open to Feedback


Could you show us a reproducive code or a testcase?

Updated by avyy (Alexander Yunin) almost 7 years ago


Bug description is incorrect, sorry. Now i want to say that implementation of String#to_regexp can breaks behavior of Regexp::union.

class String
def to_regexp
Regexp.union('/some_regexp/') #=> /regexp/

And it's not documented now.

Updated by nagachika (Tomoyuki Chikanaga) almost 7 years ago

  • Category set to doc
  • Status changed from Feedback to Assigned
  • Assignee set to zzak (Zachary Scott)
  • Target version set to 2.1.0

Hello, avyy.

That makes sense.
I think it's spec that Regexp.union internally convert arguments with to_regexp, but it is undocumented behavior. I think it's a documentation issue.


Updated by zzak (Zachary Scott) almost 7 years ago

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

This issue was solved with changeset r43061.
Alexander, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

  • re.c: [DOC] arguments of Regexp::union receive #to_regexp [Bug #8205]

Also available in: Atom PDF