[Nickle]Boolean type, twixt, static vs global, built-in profiling

[Carl Worth]

On Jul 29, Keith Packard wrote:
 > 
 > Hmm.  Perhaps the elements of the twixt could be statements instead of 
 > expressions?
 > 
 > 	twixt (if (!try_acquire ())
 > 			raise no_acq ();
 > 	       release()) 
 > 	{
 > 	}

This seems sensible to me. So, with this, "twixt ... else" would be no
more? (Personally, it's always seemed wrong to me that twixt was
inextricably entwined with an implicit if statement anyway).

 > But, it's defined to have a void type; we could extend the syntex to permit
 > return which could give a non-void value.  That would make our try_acquire
 > block look more like:
 > 
 > 	twixt (({ if (!try_acquire()) raise no_acquire(); }); release()) {
 > 	}

I'm still not clear on the intended semantics here. What is the value
that results from evaluating the "block expression" above?

-Carl

-- 
Carl Worth                                        
USC Information Sciences Institute                 cworth@east.isi.edu
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