From: recursive.madman@...
Date: 2015-03-04T21:04:51+00:00
Subject: [ruby-core:68415] [Ruby trunk - Feature #10930] Allow splat operator to work for string interpolation

Issue #10930 has been updated by Recursive Madman.


Matthew Kerwin wrote:
>  
>  I'm strongly opposed to it ever arbitrarily injecting commas, especially
>  since Array#to_s joins without any delimiter.
>  

It doesn't actually:

```ruby
2.2.0 :001 > puts %w(a b c).to_s
["a", "b", "c"]
```

`join` joins without a comma:

```ruby
2.2.0 :002 > puts %w(a b c).join
abc
```

Also, I agree with your point.


----------------------------------------
Feature #10930: Allow splat operator to work for string interpolation
https://bugs.ruby-lang.org/issues/10930#change-51762

* Author: Daniel P. Clark
* Status: Feedback
* Priority: Normal
* Assignee: 
----------------------------------------
Currently when you use the splat operator in a method it pulls the items out of the array for method parameters.

~~~ruby
def foo(a,b,c)
  puts "#{a}, #{b}, #{c}"
end

bar = [1,2,3]
foo(*bar)
# => "1, 2, 3"
~~~

So I would expect to be able to do "#{*bar}" and get either "1, 2, 3" or "1,2,3".  But when attempting this I get.

~~~ruby
baz = [1,2,3]

"#{*baz}"

# SyntaxError: (irb):53: syntax error, unexpected tSTRING_DEND, expecting '='
# "#{*baz}"
#         ^
# (irb):53: unterminated string meets end of file

"#{*[1,2,3]}"

# SyntaxError: (irb):54: syntax error, unexpected tSTRING_DEND, expecting :: or '[' or '.'
# "#{*[1,2,3]}"
#             ^
# (irb):54: unterminated string meets end of file
~~~

This doesn't work on any of the Ruby versions available 1.8 through 2.2.1.  They each produce the same error.

I propose allowing the splat operator within string interpolation to work the same as [1,2,3].join(',')

~~~ruby
fiz = [1,2,3]

"#{*fiz}"
# => "1,2,3"

"#{*[1,2,3]}"
# => "1,2,3"
~~~



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