Re: error messages with ranges

[Richard Stallman]

    The goal here is to work towards supporting caret information in GCC

What is "caret information"?

        exprs.c:47:15:{47:8-47:14}{47:17-47:24}: error: invalid operands
    to binary expression ('int *' and '_Complex float')
           P = (P-42) + Gamma*4;
               ~~~~~~ ^ ~~~~~~~

Is that what "caret information" means?

I can see how this

           P = (P-42) + Gamma*4;
               ~~~~~~ ^ ~~~~~~~

is useful for humans, and making GCC output that information
seems like a good feature.  But why is it useful to include
the location range information for the operands?

How exactly do people propose to use that location range information?