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

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;
...

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.

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
    }

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.

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

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.