NotImplementedException in Julia?

Question

C# in the NET Framework has a convenient NotImplementedException, that I can throw from code sections that I intend to write later.

Is there a similar assertion in Julia?

Answer 1

Just use error("unimplemented") or throw("unimplemented"). These exceptions are just meant to warn you that something are not implemented, so you might not want to catch or handle them by code. A ErrorException or even ASCIIString is enough.

Answer 2

In Julia, it's quite simple to create your own exception type. Last year, I added the following Exception type to Julia, along with a method to display exactly how I wanted:

const UTF_ERR_SHORT             = "invalid UTF-8 sequence starting at index <<1>> (0x<<2>> missing one or more continuation bytes)"
const UTF_ERR_CONT              = "invalid UTF-8 sequence starting at index <<1>> (0x<<2>> is not a continuation byte)"

    type UnicodeError <: Exception
        errmsg::AbstractString      ##< A UTF_ERR_ message
        errpos::Int32               ##< Position of invalid character
        errchr::UInt32              ##< Invalid character
    end

    show(io::IO, exc::UnicodeError) = print(io, replace(replace(string("UnicodeError: ",exc.errmsg),
        "<<1>>",string(exc.errpos)),"<<2>>",hex(exc.errchr)))

Now, to throw a UnicodeError, I can simply do something like:

throw(UnicodeError(UTF_ERR_SHORT, pos, chr))

to get an exception that displays exactly as I want it to.