The new std.process is ready for review

[Vladimir Panteleev]

On Monday, 25 February 2013 at 20:09:14 UTC, Lars T. Kyllingstad 
wrote:
> Exceptions are designed to handle exceptional cases.  A missing 
> environment variable isn't exceptional, it is commonplace.

I disagree. I don't know your uses cases, but as far as I can 
see, if the program expects the variable to be present in the 
environment, then it is no different from a missing file which 
the program expects to be present, or malformed user input.

> That would depend on the application.

Could you provide a specific example? It's difficult to discuss 
the merits of either approach without some use cases.

As I see, there are two major cases:

1) The program expects a variable to be set. An example of this 
is COMSPEC / SHELL. These variables ought to be set on any 
system, so the user is not expected to verify this himself. The 
variables not being set is an exceptional sitation.

2) A variable may or may not be set, such as the case of passing 
additional options via the environment (such as INCLUDE, or 
LD_PRELOAD). The program will take specific action if the 
variable is not set, such as pretending it is empty, or 
defaulting to some other setting like one in a configuration file.

It seems like your approach caters to the second situation 
exclusively. I've mentioned the problems of applying this 
approach to the first situation in my previous post.