From: Bill Kelly <billk@...>
Date: 2006-08-19T09:09:05+09:00
Subject: Re: Syntax checker wtf?

From: "inboulder" <rubyforum@wendlink.com>
> Matthew Smillie wrote:
> 
>> 
>> Actually yes.  Error identification and recovery in parsing is a
>> difficult task to begin with, engineering it into an existing system
>> is far from trivial.
>> 
> 
> The compiler throws away the line # of the start of the expression it is 
> trying to evaluate? Keeping this # around and printing it out would be a 
> great step in improving the debug info.

I wonder...

0001: class Foo
0002:
0003:   def initialize
0004:     # whatever
0005:   end
0006:
[...]
0347:   def bar
0348:     if @gargle
0349:       puts "glug!"
0350:     #end  (missing end for if)
0360:   end
[...]
0415:
0416: end    # of class Foo

Now, the error message we'd like is that the 'end' is missing for the 'if'
expression starting on line 348.

But the parser did find an 'end' that paired up with the 'if', at line 360.
And it found an 'end' for the 'def' at line 416.  Ultimately, it reaches the
end of the file, and is missing an 'end' for 'class Foo'.

So, would "unexpected EOF, missing kEND from line 1" really be all
that helpful?

It seems like a missing 'end' would probably tend to be reported for
whatever line the outermost class or module being compiled started
on... (?)


Regards,

Bill