Name of files causes error. Why?

[Andrej Mitrovic]

On 4/11/12, Xan <xancorreu at gmail.com> wrote:
> With helloworld program named with score or underscore, I receive
> the following __annoying__ error:

Underscores should work fine (and they do for me). Scores (or dashes)
can't work because an indentifier with a dash is not a valid
identifier, so a module declaration can't have dashes, and hence d
files can't have them either.