From: Michael Neumann <mneumann@...>
Date: 2004-11-17T23:28:06+09:00
Subject: Re: assert

Gavin Sinclair wrote:
> On Wednesday, November 17, 2004, 8:14:47 PM, Jeff wrote:
> 
> 
> 
>>Why not a function like ....  #breakpoint?   ?
> 
> 
>>That would then look very much like an assert.
> 
> 
>>b = 5
>>breakpoint? b == 5 ? false : true
> 
> 
>>Yes/No? I kinda like the question syntax of it.... like should I break?
> 
> 
> Well, I think
> 
>   breakpoint unless b == 5
> 
> is clearer.  But that's missing the point.  Any special method should
> have some value over the above statement.  Like
> 
>   breakpoint_unless 'b == 5'

How about this:

   def breakpoint
     file, line_no = caller.first.split(':', 2)
     reason = File.readlines(file)[line_no.to_i - 1].
       strip.sub(/^breakpoint\s+/, '')
     p reason
     # setup irb session etc.
   end

   a = 4
   breakpoint unless a == 5

This extracts the "unless a == 5" out of the source file. Of course, 
that does not work for evaled-code (unless the source-buffer is stored 
somewhere and we could access it).

But I'm sure, I'm missing something.

Regards,

   Michael