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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
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
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
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
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
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
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