public void StreamRead()
{
var rf = new DelegateStreamReadFunction(Sread);
PlEngine.SetStreamFunctionRead(PlStreamType.Input, rf);
// NOTE: read/1 needs a dot ('.') at the end
PlQuery.PlCall("assert( (test_read(A) :- read(A)) )");
PlTerm t = PlQuery.PlCallQuery("test_read(A)");
Assert.AreEqual(ValidationStringRead, t.ToString() + ".");
}
#pragma warning disable 1573
/// <inheritdoc cref="PlQuery(string)" />
/// <summary>locating the predicate in the named module.</summary>
/// <param name="module">locating the predicate in the named module.</param>
public PlQuery(string module, string goal)
{
_module = module;
_query_string = goal;
//_query_string = "(" + _query_string + ")";
if (!_query_string.EndsWith(".", StringComparison.Ordinal))
{
_query_string += ".";
}
_query_string += Environment.NewLine;
// redirect read stream
DelegateStreamReadFunction old_read_function = PlEngine._function_read;
DelegateStreamReadFunction rf = new DelegateStreamReadFunction(Sread);
if (PrologCLR.RedirectStreams)
{
PlEngine.SetStreamFunctionRead(PlStreamType.Input, rf);
}
try
{
// call read_term(Term_of_query_string, [variable_names(VN)]).
PlTerm term = PlTerm.PlVar();
PlTerm option_list = PlTerm.PlVar();
PlTerm variablenames_list = PlTerm.PlVar();
PlTerm l = PlTerm.PlTail(option_list);
l.Append(PlTerm.PlCompound("variable_names", variablenames_list));
l.Close();
PlTermV args = new PlTermV(term, option_list);
// NOTE: read/1 needs a dot ('.') at the end
if (!PlQuery.PlCall("read_term", args))
{
throw new PlLibException("PlCall read_term fails! goal:" + _query_string);
}
// restore stream function
if (PrologCLR.RedirectStreams)
{
PlEngine.SetStreamFunctionRead(PlStreamType.Input, old_read_function);
}
// set list of variables and variable_names into _queryVariables
foreach (PlTerm t in variablenames_list.ToList())
{
// t[0]='=' , t[1]='VN', t[2]=_G123
_queryVariables.Add(new PlQueryVar(t[1].ToString(), t[2]));
}
// Build the query
_name = term.Name;
// is ok e.g. for listing/0.
// Check.Require(term.Arity > 0, "PlQuery(PlTerm t): t.Arity must be greater than 0.");
_av = new PlTermV(term.Arity);
for (int index = 0; index < term.Arity; index++)
{
if (0 == libpl.PL_get_arg(index + 1, term.TermRef, _av[index].TermRef))
{
throw new PlException("PL_get_arg in PlQuery " + term.ToString());
}
}
}
#if _DEBUG
catch (Exception ex)
{
PrologCLR.ConsoleTrace(ex.Message);
}
#endif
finally
{
// NBT
}
}