Appendix F Restrictions and Limits
The ECLiPSe implementation tries to impose as few limits as possible.
The existing limits are:
The maximum arity of a predicate in ECLiPSe is 255
(this value can be queried with get_flag(max_predicate_arity, X)).
Note however that the arity of compound terms is unlimited.
- The maximum arity of external predicates in the current implementation
of ECLiPSe is 16.
- The stack and heap sizes have virtual memory limits which can be
changed using the -g, -l, -s and -p
command line options or the ec_set_option function in case of an
- When the occur check is disabled (the default)
it is possible (and sometimes useful) to create cyclic data structures.
For example, the unification of X and g(X) in
will result in a cyclic structure
X = g(X)
Not all ECLiPSe built-in predicates handle cyclic terms gracefully.
Care must be taken with all predicates which traverse the whole term, e.g.,
These will typically loop or overflow a stack when applied to cyclic terms.
Note however that, starting from version 5.6, cyclic terms are allowed in all
heap copying predicates (setval/2, bag_enter/2,
shelf_set/3, store_set/3, record/2, etc.).
X = g(g(g(g(g(...)))))