On 2010-11-07 22:29, Tomek Sowiński wrote:
This wraps up a thread from a few days ago. Pascal featured my D
examples on his Scriptometer site.
http://rigaux.org/language-study/scripting-language/
D comes 17th out of 28, so it's so-so for scripting.
I'm wondering whether the issue of D's or-expression, compared to that
of languages such as Perl and Ruby, has been discussed and dismissed.
Personally, I was a bit disappointed to learn that D had such a
traditional or-expression, seeing how much it is willing to improve over
C/C++ in other areas.
I think the following code summarizes the issue. I'm not a language
lawyer, so maybe the rules could be described more succinctly, but I
think you'll get my drift. I'm aware that with D being a typed and
compiled language, there has to a be a restriction that both
sub-expressions must be convertible to a common type, but I'm sure that
can be worked out somehow.
string func(string s)
{
/++
// A handy feature of many scripting languages, but not in D
// (in D, the type of the or-expression is bool):
// The type of the or-expression is the type of the first
// sub-expression that evaluates to true.
return s || "default";
+/
// The D equivalent, arguably more readable but also more verbose:
return s ? s : "default";
}
void main()
{
assert(func("a") == "a");
assert(func(null) == "default");
}
--
Per Å.
