Current Known Restrictions and Bugs

1. The maximum arity of external predicates in the current implementation of ECLiPSe is 16.

2. The maximum arity of a procedure in ECLiPSe is 255. The arity of compound terms is unlimited.

3. When the occur check is disabled and cyclical structures are created, e.g. in such situations as the unification of X and g(X) in

   X = g(X)
   

   which will result in a cyclic structure:

    X = g(g(g(g(g(...
   

   ECLiPSe is not able to copy such terms to the heap and so it is the programmer's responsibility to ensure that the cyclical terms are avoided in
   • Values of arrays and global variables.

   • Asserted and recorded terms.

4. When a stream is opened to the terminal in update mode, any output will discard nonconsumed input data. In files opened in update mode the null character is ignored by the parser.

As far as the functionality restrictions are concerned, ECLiPSe

actually does not make all its features available to the user, mainly to prevent an explosion of the number of built-in predicates, and also not to support the use of some techniques (e.g. destructive assignment in Prolog). ECLiPSe contains a number of predicates which are exported from the module sepia_kernel and not documented, but which can be exploited by the users if necessary.