Re: [Boost-build] Upgrade from Jam-Classic to Boost.Jam

From: João Abecasis (jpabecasis_at_[hidden])
Date: 2006-04-21 13:13:09

Marc Boris Dürner wrote:
> Hi,
> 
> I successfully used bjam to build a previous jam project by renaming bjam to
> xjam. Except for one rule (FDefines) and using the right JAM_TOOLSET no
> changes were neccesary. It would be nice if bjam could be kept compatible to
> classic-jam in the future.
> 
> I am now trying the enhanced syntax of bjam like module etc. IT seems that I
> can declare modules but not call rules in it from the global space, even
> when qualified.
> 
> Example:
> module X 
> {
> 	rule greet ( x ) { Echo x ; }
> }
> 
> 
> module Y 
> {
> 	rule salute { greet ; }
> }
> 
> # this deoes not work, but is an unknown rule
> X.greet ;
> 
> 
> Any ideas why? 

The thing is that part of the magic (<module>.<rule>) is offered by 
Boost.Build v2 and not directly by bjam. You would have to invoke the 
BBv2 rule import in order for that to work.

     module X
     {
         rule greet ( x ) { echo x ; }
     }

     import X ;

     X.greet ;

> Surprisingly, when I IMPORT X : greet : : greet ; then I can call greet like
> a global rule.

What BB does is alias X::greet to X.greet in the global namespace, where 
  X.greet is actually a single identifier.

HTH,

João