Program logic bugs vs input/environmental errors

[Steven Schveighoffer via Digitalmars-d]

On 9/27/14 7:15 PM, Walter Bright wrote:

> When I say "They are NOT for debugging programs", I mean they are NOT
> for debugging programs.

Library code often cannot make that choice. The issue with exceptions 
vs. errors is that often you don't know where the input comes from.

e.g.:

auto f = File(someInternalStringThatIsCorrupted) -> error
auto f = File(argv[1]) -> exception

How does File know what it's target file name came from?

-Steve