Fredrik Lundh wrote: > Kay Schluehr wrote: > > > If it is just a different kind of representation of common data > > structures > > but how do you know ? > > </F>
The semantics is specified by the syntax transformer so it is actually compile-time semantics relative to the base language Python . For any custom statement/expression ( expressed by a production rule / node in the parse-tree ) one or more target statements/expressions in standard Python are created. The specification of the with-statement in PEP 343 can be regarded as a good example of this definition practice. The with-statement is expanded to a "protocol" that can be expressed in Python 2.4. In a more general case this expansion might involve additional libraries e.g. ctypes or elementree. -- http://mail.python.org/mailman/listinfo/python-list