Nice Inline Syntax for DSLs

[Knud Soerensen]

On Fri, 16 Feb 2007 16:35:46 -0700, Russell Lewis wrote:

> Originally posted in digitalmars.d.announce.  I reposted here when I 
> realized my mistake.
> 
> We have been talking about using string imports and code mixins and 
> their applicability for domain-specific languages.  But the current 
> design requires either that we wrap the whole sub-language as a string, 
> or we store it in another file so that we can use string imports.  But 
> what if we allowed there to be some simple syntax which allowed us to 
> say, "Here at the top is D code; below is the DSL."  How about something 
> like:
> 
>      import my_dsl_compiler;
>      mixin(MyDSLCompiler!(import_rest_of_this_file));
>      FIRST_LINE_OF_MY_DSL
> 
> or
> 
>      import my_dsl_compiler;
>      int main(char[][] argv) {
>          // this line resolves to a lot of variable declarations
>          // and functions, including a my_dsl_main()
>          mixin MyDSLCompiler!(import_rest_of_this_file));
>          return my_dsl_main(argv);
>      }
>      FIRST_LINE_OF_MY_DSL
> 
> Sort of the idea is that whenever the compiler hits a line that includes 
> some special keyword (in the above example, it is 
> import_rest_of_this_file), it keeps on to the end of the current 
> declaration, treating it as D code.  The rest is assumed to be string 
> data which is imported into the D code above.
> 
> Think of it like a shebang line in a script, which documents how the 
> rest of the code is to be handled.
> 
> Russ

Well, we already have asm as a dsl.
Why not use a similar syntax like:

dslname 
{
...
}

We just need a way to tell the compiler which passer to use for dslname.