On Saturday, 17 June 2017 at 11:20:53 UTC, Igor Shirkalin wrote:
On Saturday, 17 June 2017 at 11:10:47 UTC, Igor wrote:
On Saturday, 17 June 2017 at 10:56:52 UTC, Igor Shirkalin
wrote:
Hello!
I have a simple C header file that looks like:
#define Name1 101
#define Name2 122
....
#define NameN 157
It comes from resource compiler and I need all these
constants to be available in my Dlang program in compile
time. It seems to me it is possible. I know I can simply
write external program (in python, for example) that does it,
but it means I should constantly run it after every change
before D compilation.
Please, can anyone help to direct me how to realize it?
Thank you in advance!
Igor Shirkalin
Maybe I am not quite understanding what you are asking but
can't you just use:
enum Name1 = 101;
enum Name2 = 122;
...
No, I need the original header file to be used in other
applications (say, resource compiler). Therefore this file is
primary. I think some pretty short code can be written in D
that use such a file to generate constants (enum Name1 = 101)
in compile time.
I'm sure others will have cleaner solutions as as a quick hack
you can read the file at compile time, modify it, and compile the
D code on the go:
import std.stdio;
import std.array;
import std.algorithm;
// Normal function that takes a list of #define and
transforms them in enum
// constants textually.
string enumify(string header) {
return header.split("\n")
.filter!(x => x.startsWith("#define Name"))
.map!(x => x.split(" "))
.map!(s => "enum " ~ s[1] ~ " = " ~ s[2] ~
";")
.join("\n");
}
unittest {
string txt = "#define Name1 101\n#define Name2 122";
assert(txt.enumify == "enum Name1 = 101;\nenum Name2 =
122;");
}
/* Our file header.h
#define Name1 101
#define Name2 122
#define Name3 157
*/
// We import the content of the file, enumify it producing D
code, and mix it
// in place to declare our constants.
//
// The string import requires compiling with
-Jpath/to/dir/with/header.h
mixin(enumify(import("header.h")));
void main(string[] args) {
writeln(Name3); // 157 // Yep, that works
pragma(msg, Name2); // 122 // Yep, that works at compile
time too
}
