Feature #14606: Change begin-else-end without rescue from warning to syntax error

• Status: Open
• Assignee: -
• Target version: -

[joker1007 (Tomohiro Hashidate)]

begin
  p :foo
else
  p :bar
end

# => :foo
# => :bar

[1,2,3].each do
  p :foo
else
  p :bar
end

# => :foo
# => :bar

begin-else-end without rescue is useless and dangerous. (especially, do-else-end is easy to mistake)
In actually, programmer never intend to write like these.
Ruby interpreter can guard this case by syntax error.

[matz (Yukihiro Matsumoto)]

Accepted.

Matz.

[mame (Yusuke Endoh)]

I'm not against the removeal.

BTW, surprisingly, the following code works "as intended."

def fib(x)
  if x >= 2
    a = fib(x - 1)
    b = fib(x - 2)
    return a + b
  end else x
end

p fib(10) #=> 55