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digitalmars.D.learn - Simple c header => Dlang constants using mixins in compile time

reply Igor Shirkalin <mathsoft inbox.ru> writes:
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
Jun 17 2017
parent reply Igor <stojkovic.igor gmail.com> writes:
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;
...
Jun 17 2017
parent reply Igor Shirkalin <mathsoft inbox.ru> writes:
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.
Jun 17 2017
parent reply Cym13 <cpicard openmailbox.org> writes:
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
     }
Jun 17 2017
parent reply Igor Shirkalin <mathsoft inbox.ru> writes:
On Saturday, 17 June 2017 at 11:23:52 UTC, Cym13 wrote:

 On Saturday, 17 June 2017 at 11:20:53 UTC, Igor Shirkalin wrote:

 [...]


 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:

 [...]


Thanks a lot! That what I was looking for.
Jun 17 2017
parent reply Seb <seb wilzba.ch> writes:
On Saturday, 17 June 2017 at 11:27:40 UTC, Igor Shirkalin wrote:

 On Saturday, 17 June 2017 at 11:23:52 UTC, Cym13 wrote:

 On Saturday, 17 June 2017 at 11:20:53 UTC, Igor Shirkalin 
 wrote:

 [...]


 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:

 [...]


 Thanks a lot! That what I was looking for.


FWIW there are tools for this as well,e.g.

https://github.com/jacob-carlborg/dstep
Jun 18 2017
parent Igor Shirkalin <mathsoft inbox.ru> writes:
On Sunday, 18 June 2017 at 16:02:38 UTC, Seb wrote:

 On Saturday, 17 June 2017 at 11:27:40 UTC, Igor Shirkalin wrote:

 On Saturday, 17 June 2017 at 11:23:52 UTC, Cym13 wrote:

 On Saturday, 17 June 2017 at 11:20:53 UTC, Igor Shirkalin 
 wrote:

 [...]


 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:

 [...]


 Thanks a lot! That what I was looking for.


 FWIW there are tools for this as well,e.g.

 https://github.com/jacob-carlborg/dstep


Thank you. I try to do it myself for learning purposes.
Jun 18 2017