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Feature #9846
closedRegexp#to_regexp
Status:
Rejected
Assignee:
-
Target version:
-
Description
There should be Regexp#to_regexp
, just as there is Array#to_ary
and String#to_str
.
p [].to_ary # => []
p ''.to_str # => ""
p //.to_regexp # undefined method `to_regexp`...
The use case is code like this:
if o.respond_to?(:to_ary)
# do something with o.to_ary
elsif o.respond_to?(:to_str)
# do something with o.to_str
elsif o.respond_to?(to_regexp) # can't do this today
# do something with o.to_regexp
The workaround is to use Regexp.try_convert
. Regexp.try_convert
accepts either a Regexp
or an object that responds to #to_regexp
; so this code works fine (and is in some ways better):
elsif re = Regexp.try_convert(o)
# do something with o
Still, that Regexp
does not respond to #to_regexp
surprised me. Does it surprise anyone else?
Files
Updated by wconrad (Wayne Conrad) over 10 years ago
Updated by justcolin (Colin Fulton) almost 8 years ago
I know this is an old issues, but this also surprised me.
Updated by nobu (Nobuyoshi Nakada) almost 8 years ago
- Description updated (diff)
case
when ary = Array.try_convert(o)
# do something with ary
when str = String.try_convert(o)
# do something with str
when re = Regexp.try_convert(o)
# do something with re
else
# do other thing
end
Updated by matz (Yukihiro Matsumoto) over 7 years ago
- Status changed from Open to Rejected
Is there any concrete use-case? Consistency is not the best reason.
This proposal leads against Duck typing.
Matz.
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