From: Brian Candler <B.Candler@...>
Date: 2004-10-07T05:13:39+09:00
Subject: Re: quality of error messages

On Thu, Oct 07, 2004 at 04:30:38AM +0900, Charles Hixson wrote:
> Perhaps not in that precise area, however when a block isn't close the 
> error message should indicate the starting line of the unclosed block, 
> instead of just mentioning a line one past the last line of the file.

I think that what you're asking for, is not what you actually want.
Consider:

class A
  def m1
  end
  def m2
  end
  def m3(x)
    if x == 3
      puts "hello"
  end
end
class B
  def m1
  end
  def m2
  end
end

The error is obvious to you, right? But because identation is not signficant
in Ruby, the parser will read it as:

class A
  def m1
  end
  def m2
  end
  def m3(x)
    if x == 3
      puts "hello"
    end
  end
  class B    # nested class definition (A::B)
    def m1
    end
    def m2
    end
  end
# missing 'end' error reported here

So where is the starting line of the unclosed block? As far as Ruby is
concerned, it is line 1 ('class A'). Unfortunately, that doesn't help you
locate the error at all.

> I have grown quite paranoid about creating large chunks of code between 
> tests...  And large here can mean only fixing more than five errors in 
> one pass.

Yeah, I understand that, hence my divide-and-conquer strategy for dealing
with broken files. An auto-indenter would help lots though; if one existed
as a standalone program (i.e. not part of emacs or whatever) I'm sure I'd
use it. Perhaps 1.9 with its userland parser will be able to do this.

Regards,

Brian.