It currently works similar to old C preprocessors but has a few extra features. This chapter describes the different preprocessor directives. This is what it can do:
#"Foo bar"is the same as
"Foo\nbar"
#define A "test"
#define B 17
#define C(X) (X)+(B)+"\n"
#define W write
#define Z Stdio.stdout
int main()
{
Z->W(C(A));
}
This puts the file index.html into the string html_doc.string html_doc=#string "index.html";