[Ur] Better compiler errors.

[Adam Chlipala]

I'm happy to accept patches improving the error messages.  I don't 
expect to spend time myself, in the near future, on this potentially 
bottomless pit of work. :D

I definitely recognize that it is unconventional to print an entire 
program subterm that is implicated in an error.  It is probably even 
often a bad idea.

On 03/13/2017 02:34 PM, Isaac Torbett wrote:
> I think the next goal for Ur/Web should be better error messages by 
> the compiler.
>
> The current ones could be moved to a verbose option (-v for instance)
>
> Current, it is very hard to read the errors that are given, unless one 
> already knows how the compiler works.
>
> A good example of how bad the error messages can be is a 8000+ line 
> error log coming from one line of code. Which yes, I did have. The fix 
> was simply parenthesis.
>
> Anyways... that's my lil` rant.
>
> Anyone else have issues reading or even understand the errors? Other 
> than slimming them down, how else can they be improved?