Re: [plt-scheme] assertions and the learning of macro-fu

[Matthias Felleisen <matthias@ccs.neu.edu>]

> > I still don't understand what is meant by
> > "expression position" here.
> 
> Maybe operator position would be clearer.  The first
> part of an sexpr that is evaluated to yield on a
> function that is apply to the rest of the sexpr
> 
>   (operator operand ...)
> 

In 

  (set! position0 position1)

_position0_ is a position where only variables may appear. 
At _position1_ you may place whatever expression you want. 

For that reason, such positions are often referred to as 
 
 expression position. 

-- Matthias