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The DLP prototype is implemented in a (syntactic) variant of POOL-X.
The implementation language used deviates from POOL-X
as described in [Am88] in that
lowercase keywords are used.
Moreover we have replaced the keywords
BEGIN, END and ROUTINE by respectively \{ , \} and fn.
We also allow the use of a macro-processor for which definitions of
the form
[] df = ...
are accepted.
We have adapted the C-preprocessor for this purpose.
For defining shorthands for types we use alias definitions
that are like macro definitions, except that parameters
are not allowed.
A more detailed description of our implementation language is
given in section \ref{impl/comp/proto:lang}.
As syntactic sugar POOL-X also allows the form ,
for objects q and n, to be used for the method call
when it occurs on the left hand side of an assignment
and for the call otherwise.
The corresponding methods for q must be defined by the user.
This notation may however also be used for arrays,
in the usual way.