Message for errors inside stdlib?

[jvdp1]

In stdlib_experimental_error.f90, there is the following example:
call error_stop("Invalid argument")
A similar case can be found in stdlib_experimental_io.f90.

When running a large program, messages such as "Invalid argument" are quite useless. Should we discuss and agree on a good way to mention error messages, e.g.,

ERROR (_name_of_the_function_): Invalid argument (_argument_)

[zbeekman]

The best way I've ever found to get good error messages and be able to do so even when using elemental or pure procedures is to define an error_stack_t class with a bunch of pure methods for pushing, popping, signalling (raising?) and then non-pure methods to catch and handle the errors.

I opened #95 to get more feedback. It could be used for the purpose described in this issue.

[certik]

A minimal improvement is to at least list the name of the function in the error message as @jvdp1 suggested. Ideally the compiler would be able to optionally generate a nice stacktrace when the program ends with a non-zero exit code.