Method getLoop

src/main/java/org/jpl7/Term.java:1096–1238

(GetTask task0, Map<term_t, Variable> vars_to_Vars)

	}

	protected static Term getLoop(GetTask task0, Map<term_t, Variable> vars_to_Vars) {
		GetTask top = task0; // initially, our stack is just the given task
		StringHolder hString = new StringHolder(); // used & reused within switch
		StringHolder hName = new StringHolder(); // used & reused within switch
		IntHolder hArity = new IntHolder(); // used & reused within switch
		Int64Holder hInt64 = new Int64Holder(); // used & reused within switch
		DoubleHolder hDouble = new DoubleHolder(); // used & reused within switch
		ObjectHolder hObject = new ObjectHolder(); // used & reused within switch
		while (top != null) { // there is a top-most task to do next
			GetTask task = top; // in case we pop or push before we've finished referring to it
			term_t term; // temp for a term ref for the switch, set appropriately before
			Term t; // temp for a Term from the switch, stashed appropriately after
			// set up term for the switch, according to task, and pop task if complete this cycle
			if (task.n > 0) { // get n-th arg of compound in task.term
				term = Prolog.new_term_ref();
				Prolog.get_arg(task.n, task.term, term); // set up term as ref to the n-th arg of compound
				if (task.n == task.arity) { // this recurrent task gets the last arg of a compound
					top = top.prev; // pop this recurrent args-of-compound task (complete this cycle)
				}
			} else if (top.n < 0) { // get (-n)th arg of dict in task.term
				term = Prolog.new_term_ref();
				Prolog.get_arg(-task.n, task.term, term); // set up term as ref to (-n)-th arg of dict
				if (-task.n == task.arity) { // this recurrent task gets the last arg of a dict
					top = top.prev; // pop this recurrent args-of-dict task (complete this cycle)
				}
			} else { // special, initial case: just get a term
				term = task.term; // get the term in task.term
				top = top.prev; // pop this simple task (complete this cycle)
			}
			switch (Prolog.term_type(term)) { // get term into t (to be stashed appropriately later)
			case Prolog.VARIABLE:
				t = null; // provisionally, until/unless set within this for loop
				for (Iterator<term_t> it = vars_to_Vars.keySet().iterator(); it.hasNext();) {
					term_t varX = it.next(); // a previously seen Prolog variable
					if (Prolog.compare(varX, term) == 0) { // referenced variables are identical
						t = (Term) vars_to_Vars.get(varX); // yield this (reused) Variable
						break; // out of enclosing for loop
					}
				}
				if (t == null) { // the Prolog variable in term has not been seen so far in this get
					Variable Var = new Variable(); // allocate a new (sequentially named, e.g. "_163") Variable
					Var.term_ = term; // TODO understand this :-/
					vars_to_Vars.put(term, Var); // enmap new Variable, keyed by term ref, lest we see it again
					t = Var; // yield this new Variable
				} // else a reused Variable was assigned to t in the for loop above
				break;
			case Prolog.ATOM: // specifically a "text" atom (see also Prolog.BLOB)
				if (Prolog.get_atom_chars(term, hString)) {
					t = new Atom(hString.value, "text");
				} else {
					throw new JPLException("Prolog.get_atom_chars failed");
				}
				break;
			case Prolog.STRING:
				if (Prolog.get_string_chars(term, hString)) {
					t = new Atom(hString.value, "string");
				} else {
					throw new JPLException("Prolog.get_string_chars failed");