generate_built_in(Name/Arity) :- predicate_property(system:Head, built_in), functor(Head, Name, Arity), \+ sub_atom(Name, 0, _, _, $). % discard reserved names
The predicate predicate_property/2 is covered by part-II of the ISO standard (modules). Although we are not aware of any Prolog system that implements part-II of the ISO standard, predicate_property/2 is available in most systems. There is little consensus on the implemented properties though. SWI-Prolog's auto loading feature further complicate this predicate.
Property is one of:
- True if the predicate can be autoloaded from the file File.
undefined, this property is not generated.
- True if the predicate is locked as a built-in predicate. This implies it cannot be redefined in its definition module and it can normally not be seen in the tracer.
- True if the predicate is defined. This property is aware of sources being reloaded, in which case it claims the predicate defined only if it is defined in another source or it has seen a definition in the current source. See compile_aux_clauses/1.
- True if assert/1 and retract/1 may be used to modify the predicate. This property is set using dynamic/1.
- True if the predicate is in the public list of the context module.
- Is true if the predicate is imported into the context module from module Module.
- Unify FileName with the name of the source file in which the
predicate is defined. See also source_file/2
and the property
line_count. Note that this reports the file of the first clause of a predicate. A more robust interface can be achieved using nth_clause/3 and clause_property/2.
- True if the predicate is defined in the C language.
- True when Module is the module in which Head is or
will be defined. Resolving this property goes through the same search
mechanism as when an undefined predicate is encountered, but does not
perform any loading. It searches (1) the module inheritance hierarchy
and (2) the autoload index if the unknown
flag is not set to
failin the target module.
- Indexes is a list of additional (hash) indexes on the
predicate. Each element of the list is a term ArgSpec-Index.
ArgSpec denotes the indexed argument(s) and is one of
- Hash on a single argument. Argument is the 1-based argument number.
- Hash on a combination of arguments.
- Index on a sub-argument. Position is a list holding first the argument of the predicate then the argument into the compound and recursively into deeper compound terms.
Index is a term
hash(Buckets, Speedup, Size, IsList). Here Buckets is the number of buckets in the hash and Speedup is the expected speedup relative to trying all clauses linearly, Size is the size of the index in memory in bytes and finally, IsList indicates that a list is created for all clauses with the same key. This is used to create deep indexes for the arguments of compound terms.
Note: This predicate property should be used for analysis and statistics only. The exact representation of Indexes may change between versions. The utilities jiti_list/0 jiti_list/1 list the jit indexes of matching predicates in a user friendly way.
- True if the predicate is defined in Prolog. We return true on this because, although the code is actually compiled, it is completely transparent, just like interpreted code.
- True if the predicate is covered by the ISO standard (ISO/IEC 13211-1).
- Unify LineNumber with the line number of the first clause of
the predicate. Fails if the predicate is not associated with a file. See
See also the
fileproperty above, notably the reference to clause_property/2.
- True if there may be multiple (or no) files providing clauses for the predicate. This property is set using multifile/1.
- If the predicate is declared as a meta-predicate using meta_predicate/1, unify Head with the head-pattern. The head-pattern is a compound term with the same name and arity as the predicate where each argument of the term is a meta-predicate specifier. See meta_predicate/1 for details.
- Details of the predicate are not shown by the debugger. This is the default for built-in predicates. User predicates can be compiled this way using the Prolog flag generate_debug_info.
- True if the predicate implements a grammar rule. See non_terminal/1.
- Do not show ports of this predicate in the debugger.
- Unify ClauseCount to the number of clauses associated with the predicate. Fails for foreign predicates. This property respects the logical update view and counts visible clauses at the moment the predicate was started.
- Similar to
- , but only counts
rules. A rule is defined as a clauses that has a body
that is not just
true(i.e., a fact).
- Database generation at which the predicate was modified for the last time. Intended to quickly assesses the validity of caches.
- Predicate is declared public using public/1. Note that without further definition, public predicates are considered undefined and this property is not reported.
- The predicate (with arity 4) is declared to provide quasi quotation syntax with quasi_quotation_syntax/1.
- Memory used for this predicate. This includes the memory of the
predicate header, the combined memory of all clauses including erased
but not yet garbage collected clauses (see garbage_collect_clauses/0
and the memory used by clause indexes (see the
indexed(Indexes)property. Excluded are lingering data structures. These are garbage data structures that have been detached from the predicate but cannot yet be reclaimed because they may be in use by some thread.
- The definition can not be modified using assertz/1
and friends. This property is the opposite from
dynamic, i.e., for each defined predicate, either
dynamicis true but never both.
- True of the predicate is tabled. The
tabled(?Flag)property can be used to obtain details about how the predicate is tabled.
- True of the predicate is tabled and Flag applies.
Any tabled predicate has one of the mutually exclusive flags
subsumptive. In addition, tabled predicates may have one or more of the following flags
- The table is shared between threads. See section 7.9.
- The table is subject to incremental tabling. See section 7.7
tabledproperty to enumerate all tabled predicates. See table/1 for details.
- If true (only possible on the multithreaded version) each thread has its own clauses for the predicate. This property is set using thread_local/1.
- True if the predicate is declared transparent using the
declaration. In the latter case the property
meta_predicate(Head)is also provided. See chapter 6 for details.
- True if a procedure definition block for the predicate exists, but there are no clauses for it and it is not declared dynamic or multifile. This is true if the predicate occurs in the body of a loaded predicate, an attempt to call it has been made via one of the meta-call predicates, the predicate has been declared as e.g., a meta-predicate or the predicate had a definition in the past. Originally used to find missing predicate definitions. The current implementation of list_undefined/0 used cross-referencing. Deprecated.
- True when predicate can be called without raising a predicate existence
error. This means that the predicate is (1) defined, (2) can be
inherited from one of the default modules (see default_module/2)
or (3) can be autoloaded. The behaviour is logically consistent iff the
visibleis provided explicitly. If the property is left unbound, only defined predicates are enumerated.
- If true, the clauses are not saved into a saved state by qsave_program/[1,2]. This property is set using volatile/1.