[eeps] EEP ???: Value-Based Error Handling Mechanisms

[e@REDACTED]

>     i'm sorry to interrupt,
>     but all you REALLY NEED is to tweak the "try..catch" a little bit,
>     in a manner that the catch clause receives and returns
>     more comprehensible values, the values that are clearly linked
>     with the failed expressions and human readable.
> 
>     you do not need a new messy CRYPTIC operator.
> 
>     try
>        {ok, Result} = foo(...)
>     , {ok, _} = foo2(...)
>     catch
>       {somehow_identify_which_line_failed, unobscured_the_rightside_value}
> 
> 
> This here is exactly the problem -- you can't somehow identify which 
> line failed unobscured with the right value.

[irrelevant technicalities skipped]

so this problem should be solved.
exactly this problem.
and another operator is not a solution.

option 1:
you introduce labels in the try's context

try
   a: {ok, Result} = foo()
, b: {ok, R} = foo2()
catch
   {a, Error_Code, Actual_Return_Value} -> ...
; {b, _} -> ...
end