It won't ever do self.send(:x=, 3). x = 3 is always a local variable assignment.
> On 14 Jan 2016, at 11:52, Clifford Heath <clifford.he...@gmail.com> wrote: > >> On 14 Jan 2016, at 9:19 AM, Simon Russell <si...@bellyphant.com> wrote: >> I'd say this "feature" probably has no useful purpose; I can't imagine a >> language designer deliberately putting it in. It's more likely to cause >> bugs than joy. >> I'm not certain, but I'm fairly your "unintended parser functionality" is >> heading in the right direction. > > No. I think it’s a necessary feature of the Ruby syntax. When Ruby sees “x = > 3”, it needs to decide whether you want an assignment to a local variable, or > “self.send(:x=, 3)”. > > So it looks around the local scope for clues about what you meant, and when > it decides that a word is the name of a local variable, it treats it that way > throughout the function. > > Clifford Heath. > >> From memory working on a Ruby compiler, Ruby allocates local variables >> before execution, but doesn't mark where they become "real". So they're >> essentially real from the start, and get assigned a default value of nil. >> It makes the whole thing easier to build; it's kind of a shortcut. >> >> So, moral of this story is... Don't assign things twice? Makes for a >> better design anyway! :) >> >> On Thu, Jan 14, 2016 at 5:35 AM, Gareth Townsend <gareth.towns...@me.com> >> wrote: >> Rubocop has a linter for shadowing variables; >> >> http://www.rubydoc.info/github/bbatsov/rubocop/Rubocop/Cop/Lint/ShadowingOuterLocalVariable >> >> Gareth Townsend >> http://www.garethtownsend.info >> >>> On 13 Jan 2016, at 22:00, David Parry <david.pa...@suranyami.com> wrote: >>> >>> Shadowing variables, which is effectively what you’ve done with >>> “misspelt_argument”, is pretty-much always a bad idea in most languages. >>> >>> In functional languages, it’s mostly impossible to do without the compiler >>> complaining, and for very good reasons, one of which you’ve pointed out. >>> >>> I suspect that tools like RuboCop would probably pick this sort of >>> abomination up. Anyone know if that’s the case? >>> >>> >>> >>>> On 13 Jan 2016, at 8:41 PM, Tom Hale <t...@hale.ee> wrote: >>>> >>>> It took some debugging to come across this one: >>>> >>>> irb(main):043:0> w >>>> NameError: undefined local variable or method `w' for main:Object >>>> from (irb):43 >>>> from /home/ravi/.rbenv/versions/2.2.3/bin/irb:11:in `<main>' >>>> irb(main):044:0> w = w >>>> => nil >>>> irb(main):045:0> >>>> >>>> Yeah, right, so what? >>>> >>>> It leads to "find the nil" fun-hunts in cases such as: >>>> >>>> irb(main):057:0> mispelt_argument = >>>> Array(mispelt_argument).flatten.uniq.map(&:name) >>>> => [] >>>> >>>> Are there any cases in which this "feature" is actually useful, or is it >>>> an unintended parser functionality? >>>> >>>> Tom >>>> >>>> -- >>>> You received this message because you are subscribed to the Google Groups >>>> "Ruby or Rails Oceania" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an >>>> email to rails-oceania+unsubscr...@googlegroups.com. >>>> To post to this group, send email to rails-oceania@googlegroups.com. >>>> Visit this group at https://groups.google.com/group/rails-oceania. >>>> For more options, visit https://groups.google.com/d/optout. >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Ruby or Rails Oceania" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to rails-oceania+unsubscr...@googlegroups.com. >>> To post to this group, send email to rails-oceania@googlegroups.com. >>> Visit this group at https://groups.google.com/group/rails-oceania. >>> For more options, visit https://groups.google.com/d/optout. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Ruby or Rails Oceania" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to rails-oceania+unsubscr...@googlegroups.com. >> To post to this group, send email to rails-oceania@googlegroups.com. >> Visit this group at https://groups.google.com/group/rails-oceania. >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Ruby or Rails Oceania" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to rails-oceania+unsubscr...@googlegroups.com. >> To post to this group, send email to rails-oceania@googlegroups.com. >> Visit this group at https://groups.google.com/group/rails-oceania. >> For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "Ruby or Rails Oceania" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to rails-oceania+unsubscr...@googlegroups.com. > To post to this group, send email to rails-oceania@googlegroups.com. > Visit this group at https://groups.google.com/group/rails-oceania. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Ruby or Rails Oceania" group. 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