OpenEuphoria

Re: Detecting the Eu version

• Posted by Jason Gade <jaygade at yahoo.com> Dec 16, 2004
• 582 views

Derek Parnell wrote:
> 
> Jason Gade wrote:
> 
> [snip]
> 
> > Okay.  Even though I wanted to kill this thread a few hours ago my interest
> > is piqued
> > now that I see more nuance in it.  How do other languages handle this
> > situation?  Most
> > of us know how C/C++ handles it (with #ifdef).  What about Python, Ruby,
> > Lua, or Perl?
> 
> The D language has a 'version()' directive which is very versitile.
> 
>   if version(2.5) {
>      .. . .
>   }
>   else
>   { . . . }
> 
> But you can also do things like ...
> 
>   if version(myspecial) {  }
> 
> On the command line you can do ...
> 
>   dmd -version=myspecial
> 
> And even inside the code you can do ...
> 
>    version = abc;
>    . . . 
>    if version(abc) { }
> 
> It's great for temporarily commenting out nested lines...
> 
>   if version(COMMENTOUT) {
>    int a = 1;
>    if version(COMMENTOUT) {
>      float b = 2.3;
>     }
>   }
> 
> The 'version()' is processed by the parser and thus you can get it
> to include or exclude compilable code in a very flexible and intuitive
> manner; so don't expect this from RDS anytime soon.
> 
> -- 
> Derek Parnell
> Melbourne, Australia
> 

Yeah, I was aware of D's version() feature... it's pretty cool.  But you would
still have to write parallel code to implement future features while retaining
backward compatability.  It is still a very useful thing, though.

=====================================
Too many freaks, not enough circuses.

j.