This module is concerned with creating signatures for a predicate. The
signature guarantees that neither the predicate itself, not one of its
callees has changed. This is used to support persistent result caching.
- goal_signature(:Goal, -Term) is det
- goal_signature(:Goal, -Term, -Vars) is det
- Replace the module and functor of Goal with a hash. For example,
user:between(1, 5, X),
becomes something like this:
'931be36e3ed89e766d332277a61664ff3c08d56a'(1, 5, X).
The hash is based on the predicate and predicates reachable though
the call graph for the most generic form.
|Vars||- is a term holding the variables in Goal/Term (these are
- deep_predicate_hash(:Head, -Hash) is det
- Compute the predicate hash of Head and all its callees and combine
this into a single hash.
- To be done
- - Could be faster by keeping track of the combined dependent
hashes of predicates per module.
- hook_predicate_hash(:Head, -Hash) is semidet[multifile]
- Hook that can be used to define the signature of a predicate. Hash
must be an SHA1 hash key (see variant_sha1/2). Defining this hook
has two effects:
- The predicate is claimed to have no dependencies. This
in itself can be exploited to prune dependency tracking.
- The signature is Hash. A typical use case is a fact base
that is derived from a file.
- predicate_dependencies(:Head, -Callees:list(callable)) is det
- True when Callees is a set (ordered list) of all predicates that are
directly or indirectly reachable through Head.
- sig_clean_cache is det
- sig_clean_cache(+M) is det
- Cleanup cached signatures and dependencies. If a module is given,
only the depedencies for the matching module are removed.
The following predicates are exported, but not or incorrectly documented.
- goal_signature(Arg1, Arg2, Arg3)
- predicate_callees(Arg1, Arg2)