Name of files causes error. Why?

[Jonathan M Davis]

On Thursday, April 12, 2012 14:30:50 Xan wrote:
> But it's a messy limitation. Why we should have it? For C++
> compatibilities?

Messy? How so? You can't put any characters in a module name which aren't 
valid identifiers. So what? Just name your module differently. Is your complaint 
that you can't just rename your cpp-file.cpp to cpp-file.d, make a few tweaks to 
its contents, and then have it compile as D? If that's the case, the file name 
is the least of your concerns. And I don't know why else you'd care about any 
"compatability" with C++ due to file names. How D interacts with C/C++ has 
nothing to do with the file names of either.

Module names can end up being used inside code to fully qualify symbol names. 
e.g.

std.algorithm.sort(arr);

If you could put characters in a module name which weren't valid in an 
identifier, this would cause serious issues for the lexer and parser.

std.algo-rithm.sort(arr);

So, it's a very reasonable restriction that a module name be required to be a 
valid identifier. And this is not unusal among programming languages with 
module systems. C/C++ doesn't have such restrictions, because they had the 
misfortune to choose the whole #include mess. Their choice is p probably due - 
at least in part - to computing restrictions at the time which would have made 
putting all of the symbols in memory too expensive, so as bad as it is, they 
probably didn't have much choice, but it still has horrible problems - some of 
which are listed here: http://www.drdobbs.com/blogs/cpp/228701711

D's modules are _far_ better, even if with their restrictions on file names.

- Jonathan M Davis