What is D?
D is a general purpose systems and applications programming language. It is a higher level language than C++, but retains the ability to write high performance code and interface directly with the operating system API's and with hardware. D is well suited to writing medium to large scale million line programs with teams of developers. D is easy to learn, provides many capabilities to aid the programmer, and is well suited to aggressive compiler optimization technology.
D is not a scripting language, nor an interpreted language. It doesn't come with a VM, a religion, or an overriding philosophy. It's a practical language for practical programmers who need to get the job done quickly, reliably, and leave behind maintainable, easy to understand code.
D is the culmination of decades of experience implementing compilers for many diverse languages, and attempting to construct large projects using those languages. D draws inspiration from those other languages (most especially C++) and tempers it with experience and real world practicality.
看个例子.
import std.file;
int main (char[][] args)
{
int w_total;
int l_total;
int c_total;
printf (" lines words bytes file\n");
foreach (char[] arg; args[1 .. args.length])
{
char[] input;
int w_cnt, l_cnt, c_cnt;
int inword;
input = cast(char[])std.file.read(arg);
foreach (char c; input)
{
if (c == '\n')
++l_cnt;
if (c != ' ')
{
if (!inword)
{
inword = 1;
++w_cnt;
}
}
else
inword = 0;
++c_cnt;
}
printf ("%8lu%8lu%8lu %.*s\n", l_cnt, w_cnt, c_cnt, arg);
l_total += l_cnt;
w_total += w_cnt;
c_total += c_cnt;
}
if (args.length > 2)
{
printf ("--------------------------------------\n%8lu%8lu%8lu total",
l_total, w_total, c_total);
}
return 0;
}
