Issue #16295 has been updated by phluid61 (Matthew Kerwin).


byroot (Jean Boussier) wrote:
> phluid61 (Matthew Kerwin) wrote:
> > It doesn't exactly fit the way messages are named in Ruby, but how about:
> > 
> > ```ruby
> > alias -@ frozen
> > alias +@ thawed
> > ```
> 
> `-@` does more than freezing the string, it also lookup the fstring table and potentially returns you a pre-existing instance, potentially deduplicating equal strings. I believe the alias name should reflect this intent, otherwise people might confuse it with a simple alias to `freeze`.
> 

I think most of that functionality is equivalent to implementation detail, as far as String itself is concerned. Deduplication is a concern of the ObjectSpace.

If it's important, document it in the rdoc. The method name doesn't have to describe everything the method does.

Also: why is something like "dedup" any better? It sounds like a simple alias for `intern` (which, incidentally, returns a deduplicated, frozen instance..) 

----------------------------------------
Feature #16295: Chainable aliases for String#-@ and String#+@
https://bugs.ruby-lang.org/issues/16295#change-82547

* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
----------------------------------------
Original discussion https://bugs.ruby-lang.org/issues/16150?next_issue_id=16147&prev_issue_id=16153#note-40

In #16150, @headius raised the following concern about `String#-@` and `String#+@`:

headius (Charles Nutter) wrote:
> > Not exactly, -@ and +@ makes this much simpler
> 
> I do like the unary operators, but they also have some precedence oddities:
> 
> ```
> >> -"foo".size
> => -3
> >> (-"foo").size
> => 3
> ```
> 
> And it doesn't work at all if you're chaining method calls:
> 
> ```
> >> +ary.to_s.frozen?
> NoMethodError: undefined method `+@' for false:FalseClass
> 	from (irb):8
> 	from /usr/bin/irb:11:in `<main>'
> ```
> 
> But you are right, instead of the explicit `dup` with possible freeze you could use `-` or `+` on the result of `to_s`. However it's still not safe to modify it since it would modify the original string too.

After working for quite a while with those, I have to say I agree. They very often force to use parentheses, which is annoying, and an indication that regular methods would be preferable to unary operators.


In response @matz proposed to alias them as `String#+` and `String#-` without arguments:

>  How about making String#+ and #- without argument behave like #+@ and #-@ respectively, so that we can write:
>  
>  ```
>  "foo".-.size
>  ary.+.to_s.frozen?
>  ```


My personal opinion is that descriptive method names would be preferable to `+/-`:

> IMHO `.-` and `.+` is not very elegant. Proper method names explaining the intent would be preferable.
> 
>   - `-@` could be `dedup`, or `deduplicate`.
>   - `+@` could be `mutable` or `mut`.





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