/// <summary>
/// Is a slot name valid.
/// </summary>
/// <param name="slotName">the name of the slot</param>
/// <returns>whether a slot name is present in the object</returns>
public bool HasSlot(string slotName)
{
using (var s = new ProtectedPointer(Engine, GetFunction <Rf_mkString>()(InternalString.NativeUtf8FromString(slotName))))
{
return(this.GetFunction <R_has_slot>()(this.DangerousGetHandle(), s));
}
}
/// <summary>
/// Gets the element at the specified index.
/// </summary>
/// <remarks>Used for pre-R 3.5 </remarks>
/// <param name="index">The zero-based index of the element to get.</param>
/// <returns>The element at the specified index.</returns>
protected override string GetValue(int index)
{
int offset = GetOffset(index);
IntPtr pointerItem = Marshal.ReadIntPtr(DataPointer, offset);
if (pointerItem == Engine.NaStringPointer)
{
return(null);
}
IntPtr pointer = IntPtr.Add(pointerItem, Marshal.SizeOf(typeof(Internals.PreALTREP.VECTOR_SEXPREC)));
return(InternalString.StringFromNativeUtf8(pointer));
}
private SymbolicExpression Parse(string statement, StringBuilder incompleteStatement, REnvironment environment = null)
{
incompleteStatement.Append(statement);
var s = GetFunction <Rf_mkString>()(InternalString.NativeUtf8FromString(incompleteStatement.ToString()));
string errorStatement;
using (new ProtectedPointer(this, s))
{
ParseStatus status;
var vector = new ExpressionVector(this, GetFunction <R_ParseVector>()(s, -1, out status, NilValue.DangerousGetHandle()));
switch (status)
{
case ParseStatus.OK:
incompleteStatement.Clear();
if (vector.Length == 0)
{
return(null);
}
using (new ProtectedPointer(vector))
{
SymbolicExpression result;
if (!vector.First().TryEvaluate((environment == null) ? GlobalEnvironment : environment, out result))
{
throw new EvaluationException(LastErrorMessage);
}
if (AutoPrint && !result.IsInvalid && GetVisible())
{
GetFunction <Rf_PrintValue>()(result.DangerousGetHandle());
}
return(result);
}
case ParseStatus.Incomplete:
return(null);
case ParseStatus.Error:
// TODO: use LastErrorMessage if below is just a subset
var parseErrorMsg = this.GetAnsiString("R_ParseErrorMsg");
errorStatement = incompleteStatement.ToString();
incompleteStatement.Clear();
throw new ParseException(status, errorStatement, parseErrorMsg);
default:
errorStatement = incompleteStatement.ToString();
incompleteStatement.Clear();
throw new ParseException(status, errorStatement, "");
}
}
}
private string ReadString(IntPtr pointer, int offset)
{
pointer = Marshal.ReadIntPtr(pointer, offset);
if (Engine.Compatibility == REngine.CompatibilityMode.ALTREP)
{
pointer = GetFunction <DATAPTR_OR_NULL>()(pointer);
}
else
{
pointer = IntPtr.Add(pointer, Marshal.SizeOf(Engine.GetVectorSexprecType()));
}
return(InternalString.StringFromNativeUtf8(pointer));
}
/// <summary>
/// Gets all value names.
/// </summary>
/// <returns>The names of attributes</returns>
public string[] GetAttributeNames()
{
int length = this.GetFunction <Rf_length>()(this.sexp.attrib);
var names = new string[length];
IntPtr pointer = this.sexp.attrib;
for (int index = 0; index < length; index++)
{
var node = (SEXPREC)Marshal.PtrToStructure(pointer, typeof(SEXPREC));
var attribute = (SEXPREC)Marshal.PtrToStructure(node.listsxp.tagval, typeof(SEXPREC));
IntPtr name = attribute.symsxp.pname;
names[index] = new InternalString(Engine, name);
pointer = node.listsxp.cdrval;
}
return(names);
}
/// <summary>
/// Gets the element at the specified index.
/// </summary>
/// <remarks>Used for R 3.5 and higher, to account for ALTREP objects</remarks>
/// <param name="index">The zero-based index of the element to get.</param>
/// <returns>The element at the specified index.</returns>
protected override string GetValueAltRep(int index)
{
// To work with ALTREP (introduced in R 3.5.0) and non-ALTREP objects, we will get strings
// via STRING_ELT, instead of offseting the DataPointer. This lets R manage the details of
// ALTREP conversion for us.
IntPtr objPointer = GetFunction <STRING_ELT>()(this.DangerousGetHandle(), (IntPtr)index);
if (objPointer == Engine.NaStringPointer)
{
return(null);
}
IntPtr stringData = GetFunction <DATAPTR_OR_NULL>()(objPointer);
return(InternalString.StringFromNativeUtf8(stringData));
}
/// <summary>
/// Gets the element at the specified index.
/// </summary>
/// <remarks>Used for R 3.5 and higher, to account for ALTREP objects</remarks>
/// <param name="index">The zero-based index of the element to get.</param>
/// <returns>The element at the specified index.</returns>
protected override string GetValueAltRep(int index)
{
// To work with ALTREP (introduced in R 3.5.0) and non-ALTREP objects, we will get strings
// via STRING_ELT, instead of offseting the DataPointer. This lets R manage the details of
// ALTREP conversion for us.
IntPtr objPointer = GetFunction <STRING_ELT>()(this.DangerousGetHandle(), (ulong)index);
if (objPointer == Engine.NaStringPointer)
{
return(null);
}
IntPtr stringData = IntPtr.Add(objPointer, Marshal.SizeOf(typeof(Internals.ALTREP.VECTOR_SEXPREC)));
return(InternalString.StringFromNativeUtf8(stringData));
}
/// <summary>
/// Gets all value names.
/// </summary>
/// <returns>The names of attributes</returns>
public string[] GetAttributeNames()
{
int length = this.GetFunction <Rf_length>()(this.sexp.attrib);
var names = new string[length];
IntPtr pointer = this.sexp.attrib;
var sexprecType = engine.GetSEXPRECType();
for (int index = 0; index < length; index++)
{
dynamic node = Convert.ChangeType(Marshal.PtrToStructure(pointer, sexprecType), sexprecType);
var attribute = Convert.ChangeType(Marshal.PtrToStructure(node.listsxp.tagval, sexprecType), sexprecType);
IntPtr name = attribute.symsxp.pname;
names[index] = new InternalString(Engine, name);
pointer = node.listsxp.cdrval;
}
return(names);
}
/// <summary>
/// 通过给定的文件流，判断文件的编码类型
/// </summary>
/// <param name="ss">字节流</param>
/// <returns>文件的编码类型</returns>
public static System.Text.Encoding GetType(byte[] ss)
{
byte[] unicode = new byte[] { 0xFF, 0xFE, 0x41 };
byte[] unicodeBig = new byte[] { 0xFE, 0xFF, 0x00 };
byte[] utf8 = new byte[] { 0xEF, 0xBB, 0xBF }; //带BOM
sbyte[] tsbyte = (sbyte[])(Array)ss;
Encoding reVal = Encoding.Default;
if (InternalString.UTF8Probability(tsbyte) > 0 || (ss[0] == 0xEF && ss[1] == 0xBB && ss[2] == 0xBF))
{
reVal = Encoding.UTF8;
}
else if (ss[0] == 0xFE && ss[1] == 0xFF && ss[2] == 0x00)
{
reVal = Encoding.BigEndianUnicode;
}
else if (ss[0] == 0xFF && ss[1] == 0xFE && ss[2] == 0x41)
{
reVal = Encoding.Unicode;
}
return(reVal);
}
private string ReadString(IntPtr pointer, int offset)
{
pointer = Marshal.ReadIntPtr(pointer, offset);
pointer = IntPtr.Add(pointer, Marshal.SizeOf(Engine.GetVectorSexprecType()));
return(InternalString.StringFromNativeUtf8(pointer));
}
private string ReadString(IntPtr pointer, int offset)
{
pointer = Marshal.ReadIntPtr(pointer, offset);
pointer = IntPtr.Add(pointer, Marshal.SizeOf(typeof(VECTOR_SEXPREC)));
return(InternalString.StringFromNativeUtf8(pointer));
}
/// <summary>
/// Gets/sets the value of a slot
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
public SymbolicExpression this[string name]
{
get
{
checkSlotName(name);
IntPtr slotValue;
using (var s = new ProtectedPointer(Engine, GetFunction <Rf_mkString>()(InternalString.NativeUtf8FromString(name))))
{
slotValue = this.GetFunction <R_do_slot>()(this.DangerousGetHandle(), s);
}
return(new SymbolicExpression(Engine, slotValue));
}
set
{
checkSlotName(name);
using (var s = new ProtectedPointer(Engine, GetFunction <Rf_mkString>()(InternalString.NativeUtf8FromString(name))))
{
using (new ProtectedPointer(this))
{
this.GetFunction <R_do_slot_assign>()(this.DangerousGetHandle(), s, value.DangerousGetHandle());
}
}
}
}
