interface identity (was Re: Proposed new dependency: github.com/juju/errors (and github.com/juju/errgo))

[Tim Penhey]

On 28/05/14 12:43, Nate Finch wrote:
> This sounds like one of those "if you have to ask this question, you're
> doing something wrong".
> 
> Can you give an example of where we need this?

Sure... let's say we have a stack of errors, for simplicity of the
argument lets say it is a slice of error interface values.

 stack []error

 * an error is pushed on to the stack initially, we now have one error
 * the same error is pushed (or appended - I don't care)
 * we now have the same error twice
 * I push a new error on the stack, so it looks a little like this
   [err1, err1, err2] right?

Now iterating through this slice I want to know when the error changes.

There seems to be no clean way to do this.

Tim