khanat-opennel-code/code/ryzom/client/src/interface_v3/interface_expr.cpp

// Ryzom - MMORPG Framework <http://dev.ryzom.com/projects/ryzom/>
// Copyright (C) 2010  Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "stdpch.h"
#include "interface_expr.h"
#include "interface_manager.h"
#include "interface_expr_node.h"
#include "../misc.h"
#include "nel/misc/algo.h"
#include <algorithm>

using namespace std;
using namespace NLMISC;

// Yoyo: Act like a singleton, else registerUserFct may crash.
CInterfaceExpr::TUserFctMap *CInterfaceExpr::_UserFct= NULL;

static const std::string ExprLuaId="lua:";

//==================================================================
// release memory
void CInterfaceExpr::release()
{
	delete _UserFct;
	_UserFct = NULL;
}

//==================================================================
void formatLuaCall(const std::string &expr, std::string &tempStr)
{
	/* Call the LUA interface exp fct, with the script as line, and resolve string definition conflicts:
		eg:  replace
			lua:getSkillFromName('SM')
		into
			lua('getSkillFromName(\"SM\")')
	*/
	tempStr= expr.substr(ExprLuaId.size());			// eg: tempStr= getSkillFromName('SM')
	while(strFindReplace(tempStr, "'", "\\\""));	// eg: tempStr= getSkillFromName(\"SM\")
	tempStr= string("lua('") + tempStr + "')";		// eg: tempStr= lua('getSkillFromName(\"SM\")')
}

//==================================================================
bool CInterfaceExpr::eval(const std::string &expr, CInterfaceExprValue &result, std::vector<ICDBNode *> *nodes, bool noFctCalls /* = false */)
{
	// Yoyo: Special InterfaceExpr Form to execute lua code?
	if(expr.compare(0, ExprLuaId.size(), ExprLuaId) ==0 )
	{
		std::string	tempStr;
		formatLuaCall(expr, tempStr);
		return evalExpr(tempStr.c_str(), result, nodes, noFctCalls) != NULL;
	}
	else
	{
		return evalExpr(expr.c_str(), result, nodes, noFctCalls) != NULL;
	}
}

//==================================================================
CInterfaceExprNode *CInterfaceExpr::buildExprTree(const std::string &expr)
{
	CInterfaceExprNode *node;

	// Yoyo: Special InterfaceExpr Form to execute lua code?
	if(expr.compare(0, ExprLuaId.size(), ExprLuaId) ==0 )
	{
		std::string	tempStr;
		formatLuaCall(expr, tempStr);
		if (!buildExprTree(tempStr.c_str(), node)) return false;
	}
	else
	{
		if (!buildExprTree(expr.c_str(), node)) return false;
	}

	return node;
}


//==================================================================
void CInterfaceExpr::registerUserFct(const char *name,TUserFct fct)
{
	if(!_UserFct)	_UserFct= new TUserFctMap;

	nlassert(fct != NULL);
	(*_UserFct)[std::string(name)] = fct;
}

//==================================================================
/** tool fct : skip space, tab and carret-returns
  */
static const char *skipBlank(const char *start)
{
	nlassert(start);
	while (*start == ' ' || *start == '\t' || *start == '\r' || *start == '\n') ++start;
	return start;
}

//==================================================================
const char *CInterfaceExpr::evalExpr(const char *expr, CInterfaceExprValue &result, std::vector<ICDBNode *> *nodes, bool noFctCalls)
{
	nlassert(expr != NULL);
	expr = skipBlank(expr);
	if (isalpha(*expr)) // alpha character means this is a function name
	{
		return evalFct(expr, result, nodes, noFctCalls);
	}
	else if (*expr == '@') // is it a database entry ?
	{
		++ expr;
		expr = skipBlank(expr);
		return evalDBEntry(expr, result, nodes);
	}

	// try to parse a literal value
	const char *newExpr = result.initFromString(expr);
	if (!newExpr)
	{
		nlwarning("<CInterfaceExpr::evalExpr> : syntax error : %s", expr);
		return NULL;
	}
	return newExpr;
}

//==================================================================
const char *CInterfaceExpr::buildExprTree(const char *expr, CInterfaceExprNode *&result)
{
	nlassert(expr != NULL);
	expr = skipBlank(expr);
	if (isalpha(*expr)) // alpha character means this is a function name
	{
		return buildFctNode(expr, result);
	}
	else if (*expr == '@') // is it a database entry ?
	{
		++ expr;
		expr = skipBlank(expr);
		return buildDBEntryNode(expr, result);
	}
	else
	{
		CInterfaceExprValue value;
		// try to parse a literal value
		const char *newExpr = value.initFromString(expr);
		if (!newExpr)
		{
			nlwarning("<CInterfaceExpr::buildExprTree> : syntax error : %s", expr);
			return NULL;
		}
		CInterfaceExprNodeValue *node = new CInterfaceExprNodeValue;
		node->Value = value;
		result = node;
		return newExpr;
	}
	return NULL;
}


//==================================================================
const char *CInterfaceExpr::evalFct(const char *expr, CInterfaceExprValue &result, std::vector<ICDBNode *> *nodes, bool noFctCalls)
{
	if(!_UserFct)	_UserFct= new TUserFctMap;

	const char *start = expr;
	while (isalnum(*expr)) ++ expr;
	std::string fctName(start, expr - start);
	// find entry in the map
	TUserFctMap::iterator fctIt = _UserFct->find(fctName);
	if (fctIt == _UserFct->end())
	{
		nlwarning("<CInterfaceExpr::evalFct> : Unknown function %s", fctName.c_str());
		return NULL;
	}
	nlassert(fctIt->second != NULL);
	// eval list of arguments
	TArgList argList;
	expr = skipBlank(expr);
	if (*expr != '(')
	{
		nlwarning("<CInterfaceExpr::evalFct> : '(' expected for function %s", fctName.c_str());
		return NULL;
	}
	++ expr;
	expr = skipBlank(expr);
	if (*expr != ')')
	{
		for(;;)
		{
			expr = skipBlank(expr);
			// parse an argument
			argList.push_back(CInterfaceExprValue());
			expr = evalExpr(expr, argList.back(), nodes, noFctCalls);
			if (expr == NULL) return NULL;
			expr = skipBlank(expr);
			if (*expr == ')') break;
			// if it isn't the end of the expression, then we should find a ',' before next argument
			if (*expr != ',')
			{
				nlwarning("<CInterfaceExpr::evalFct> : ',' expected in function %s", fctName.c_str());
				return NULL;
			}
			++ expr;
		}
	}
	++ expr;
	// call the fct
	if (!noFctCalls) // should we make terminal function calls ?
	{
		if (fctIt->second(argList, result)) return expr;
	}
	else
	{
		return expr;
	}
	return NULL;
}

//==================================================================
const char *CInterfaceExpr::buildFctNode(const char *expr, CInterfaceExprNode *&result)
{
	if(!_UserFct)	_UserFct= new TUserFctMap;

	const char *start = expr;
	while (isalnum(*expr)) ++ expr;
	std::string fctName(start, expr - start);
	// find entry in the map
	TUserFctMap::iterator fctIt = _UserFct->find(fctName);
	if (fctIt == _UserFct->end())
	{
		nlwarning("<CInterfaceExpr::buildFctNode> : Unknown function %s", fctName.c_str());
		return NULL;
	}
	nlassert(fctIt->second != NULL);
	// List of parameters
	expr = skipBlank(expr);
	if (*expr != '(')
	{
		nlwarning("<CInterfaceExpr::buildFctNode> : '(' expected for function %s", fctName.c_str());
		return NULL;
	}
	++ expr;
	expr = skipBlank(expr);
	std::vector<CInterfaceExprNode *> Params;
	if (*expr != ')')
	{
		for(;;)
		{
			expr = skipBlank(expr);
			// parse an argument
			CInterfaceExprNode *node = NULL;
			expr = buildExprTree(expr, node);
			if (expr == NULL)
			{
				for(uint k = 0; k < Params.size(); ++k)
				{
					delete Params[k];
				}
				return NULL;
			}
			Params.push_back(node);
			expr = skipBlank(expr);
			if (*expr == ')') break;
			// if it isn't the end of the expression, then we should find a ',' before next argument
			if (*expr != ',')
			{
				for(uint k = 0; k < Params.size(); ++k)
				{
					delete Params[k];
				}
				nlwarning("CInterfaceExpr::evalFct : ',' expected in function %s", fctName.c_str());
				return NULL;
			}
			++ expr;
		}
	}
	++ expr;
	CInterfaceExprNodeValueFnCall *node = new CInterfaceExprNodeValueFnCall;
	node->Params.swap(Params);
	node->Func = fctIt->second;
	result = node;
	return expr;
}

//==================================================================
const char *CInterfaceExpr::evalDBEntry(const char *expr, CInterfaceExprValue &result, std::vector<ICDBNode *> *nodes)
{
	std::string dbEntry;
	expr = unpackDBentry(expr, nodes, dbEntry);
	if (!expr) return NULL;
	// TestYoyo
	//nlassert(CInterfaceManager::getInstance()->getDbProp(dbEntry, false) || CInterfaceManager::getInstance()->getDbBranch(dbEntry));
	// get the db value
	CCDBNodeLeaf *nl = CInterfaceManager::getInstance()->getDbProp(dbEntry);
	if (nl)
	{
		if (nodes)
		{
			// insert node if not already present
			if (std::find(nodes->begin(), nodes->end(), nl) == nodes->end())
			{
				nodes->push_back(nl);
			}
		}
		result.setInteger(nl->getValue64());
		return expr;
	}
	else
	{
		CCDBNodeBranch *nb = CInterfaceManager::getInstance()->getDbBranch(dbEntry);
		if (nodes && nb)
		{
			if (std::find(nodes->begin(), nodes->end(), nb) == nodes->end())
			{
				nodes->push_back(nb);
			}
		}
		if (!nb) return NULL;
		result.setInteger(0);
		return expr;
	}
	return NULL;
}

//==================================================================
const char *CInterfaceExpr::buildDBEntryNode(const char *expr, CInterfaceExprNode *&result)
{
	std::string dbEntry;
	bool indirection;
	const char *startChar = expr;
	expr = unpackDBentry(expr, NULL, dbEntry, &indirection);
	if (!expr) return NULL;
	if (indirection)
	{
		// special node with no optimisation
		CInterfaceExprNodeDependantDBRead *node = new CInterfaceExprNodeDependantDBRead;
		node->Expr.resize(expr - startChar + 1);
		std::copy(startChar, expr, node->Expr.begin() + 1);
		node->Expr[0] = '@';
		result = node;
		return expr;
	}
	else
	{
		// TestYoyo
		//nlassert(CInterfaceManager::getInstance()->getDbProp(dbEntry, false) || CInterfaceManager::getInstance()->getDbBranch(dbEntry));
		CCDBNodeLeaf *nl = CInterfaceManager::getInstance()->getDbProp(dbEntry);
		if (nl)
		{
			CInterfaceExprNodeDBLeaf *node = new CInterfaceExprNodeDBLeaf;
			node->Leaf = nl;
			result = node;
			return expr;
		}
		else
		{
			CCDBNodeBranch *nb = CInterfaceManager::getInstance()->getDbBranch(dbEntry);
			if (nb)
			{
				CInterfaceExprNodeDBBranch *node = new CInterfaceExprNodeDBBranch;
				node->Branch = nb;
				result = node;
				return expr;
			}
		}
		return NULL;
	}
}

//==================================================================
const char *CInterfaceExpr::unpackDBentry(const char *expr, std::vector<ICDBNode *> *nodes, std::string &dest, bool *hasIndirections /* = NULL*/)
{
	std::string entryName;
	bool indirection = false;
	for (;;)
	{
		if (*expr == '[')
		{
			indirection = true;
			++ expr;
			std::string subEntry;
			expr = unpackDBentry(expr, nodes, subEntry);
			if (!expr) return NULL;
			// Read DB Index Offset.
			sint32	indirectionOffset= 0;
			if (*expr == '-' || *expr =='+' )
			{
				bool	negative= *expr == '-';
				std::string offsetString;
				++ expr;
				while(*expr!=0 && isdigit(*expr))
				{
					offsetString.push_back(*expr);
					++ expr;
				}
				// get offset
				fromString(offsetString, indirectionOffset);
				if(negative)
					indirectionOffset= -indirectionOffset;
			}
			// Test end of indirection
			if (*expr != ']')
			{
				nlwarning("CInterfaceExpr::unpackDBentry: ']' expected");
				return NULL;
			}
			++ expr;
			// get the db value at sub entry
			// TestYoyo
			//nlassert(CInterfaceManager::getInstance()->getDbProp(subEntry, false) || CInterfaceManager::getInstance()->getDbBranch(subEntry));
			CCDBNodeLeaf *nl = CInterfaceManager::getInstance()->getDbProp(subEntry);
			if (nodes)
			{
				if (std::find(nodes->begin(), nodes->end(), nl) == nodes->end())
				{
					nodes->push_back(nl);
				}
			}
			// compute indirection, (clamp).
			sint32	indirectionValue= nl->getValue32() + indirectionOffset;
			indirectionValue= std::max((sint32)0, indirectionValue);

			// Append to entry name.
			entryName += NLMISC::toString(indirectionValue);
		}
		else if (isalnum(*expr) || *expr == '_' || *expr == ':')
		{
			entryName += *expr;
			++ expr;
		}
		else
		{
			break;
		}
	}
	if (hasIndirections)
	{
		*hasIndirections = indirection;
	}
	dest = entryName;
	return expr;
}


//==================================================================
bool CInterfaceExpr::evalAsInt(const std::string &expr, sint64 &dest)
{
	CInterfaceExprValue result;
	if (!eval(expr, result)) return false;
	if (!result.toInteger())
	{
		nlwarning("<CInterfaceExpr::evalAsInt> Can't convert value to an integer, expr = %s", expr.c_str());
		return false;
	}
	dest = result.getInteger();
	return true;
}

//==================================================================
bool CInterfaceExpr::evalAsDouble(const std::string &expr, double &dest)
{
	CInterfaceExprValue result;
	if (!eval(expr, result)) return false;
	if (!result.toDouble())
	{
		nlwarning("<CInterfaceExpr::evalAsDouble> Can't convert value to a double, expr = %s", expr.c_str());
		return false;
	}
	dest = result.getDouble();
	return true;
}

//==================================================================
bool CInterfaceExpr::evalAsBool(const std::string &expr, bool &dest)
{
	CInterfaceExprValue result;
	if (!eval(expr, result)) return false;
	if (!result.toBool())
	{
		nlwarning("<CInterfaceExpr::evalAsBool> Can't convert value to a boolean, expr = %s", expr.c_str());
		return false;
	}
	dest = result.getBool();
	return true;
}

//==================================================================
bool CInterfaceExpr::evalAsString(const std::string &expr, std::string &dest)
{
	CInterfaceExprValue result;
	if (!eval(expr, result)) return false;
	if (!result.toString())
	{
		nlwarning("<CInterfaceExpr::evalAsString> Can't convert value to a string, expr = %s", expr.c_str());
		return false;
	}
	dest = result.getString();
	return true;
}

//==================================================================
//==================================================================
//==================================================================
//==================================================================


//==================================================================
bool CInterfaceExprValue::toBool()
{
	switch(_Type)
	{
		case Boolean: return true;
		case Integer: setBool(_IntegerValue != 0); return true;
		case Double:  setBool(_DoubleValue != 0); return true;
		case String:  return evalBoolean(_StringValue.toString().c_str()) != NULL;
		default: break;
	}
	return false;

}

//==================================================================
bool CInterfaceExprValue::toInteger()
{
	switch(_Type)
	{
		case Boolean: setInteger(_BoolValue ? 1 : 0); return true;
		case Integer: return true;
		case Double:  setInteger((sint64) _DoubleValue); return true;
		case String:
			if (evalNumber(_StringValue.toString().c_str())) return toInteger();
			return false;
		case RGBA:	setInteger((sint64) _RGBAValue); return true;
		default: break;
	}
	return false;
}

//==================================================================
bool CInterfaceExprValue::toDouble()
{
	switch(_Type)
	{
		case Boolean:	setDouble(_BoolValue ? 1 : 0); return true;
		case Integer:	setDouble((double) _IntegerValue); return true;
		case Double:	return true;
		case String:
			if (evalNumber(_StringValue.toString().c_str())) return toBool();
			return false;
		case RGBA:	setDouble((double) _RGBAValue); return true;
		default: break;
	}
	return false;
}

//==================================================================
bool CInterfaceExprValue::toString()
{
	switch(_Type)
	{
		case Boolean:	setString(_BoolValue ? "true" : "false"); return true;
		case Integer:	setString(NLMISC::toString(_IntegerValue)); return true;
		case Double:	setString(NLMISC::toString("%.2f", _DoubleValue)); return true;
		case String:	return true;
		case RGBA:
		{
			uint	r,g,b,a;
			r= (_RGBAValue&0xff);
			g= ((_RGBAValue>>8)&0xff);
			b= ((_RGBAValue>>16)&0xff);
			a= ((_RGBAValue>>24)&0xff);
			setString(NLMISC::toString("%d %d %d %d", r, g, b, a));
			return true;
		}
		default: break;
	}
	return false;
}

//==================================================================
bool CInterfaceExprValue::toRGBA()
{
	switch(_Type)
	{
		case RGBA: return true;
		case Integer: setRGBA(NLMISC::CRGBA((uint8)(_IntegerValue&0xff), (uint8)((_IntegerValue>>8)&0xff),
											(uint8)((_IntegerValue>>16)&0xff), (uint8)((_IntegerValue>>24)&0xff))); return true;
		case String:
			setRGBA(stringToRGBA(_StringValue.toString().c_str())); return true;
		default: break;
	}
	return false;
}

//==================================================================
bool CInterfaceExprValue::isNumerical() const
{
	return _Type == Boolean || _Type == Integer || _Type == Double;
}

//==================================================================
const char *CInterfaceExprValue::initFromString(const char *expr)
{
	nlassert(expr);
	expr = skipBlank(expr);
	if (isdigit(*expr) || *expr == '.' || *expr == '-') return evalNumber(expr);
	switch(*expr)
	{
		case 't':
		case 'T':
		case 'f':
		case 'F':
			return evalBoolean(expr);
		case '\'':
			return evalString(expr);
		default:
			return NULL;
	}
}

//==================================================================
const char *CInterfaceExprValue::evalBoolean(const char *expr)
{
	nlassert(expr);
	expr = skipBlank(expr);
	if (toupper(expr[0]) == 'T' &&
		toupper(expr[1]) == 'R' &&
		toupper(expr[2]) == 'U' &&
		toupper(expr[3]) == 'E')
	{
		setBool(true);
		return expr + 4;
	}
	//
	if (toupper(expr[0]) == 'F' &&
		toupper(expr[1]) == 'A' &&
		toupper(expr[2]) == 'L' &&
		toupper(expr[3]) == 'S' &&
		toupper(expr[4]) == 'E')
	{
		setBool(false);
		return expr + 5;
	}
	return NULL;
}

//==================================================================
const char *CInterfaceExprValue::evalNumber(const char *expr)
{
	bool negative;
	bool hasPoint = false;

	expr = skipBlank(expr);

	if (*expr == '-')
	{
		negative = true;
		++ expr;
		expr = skipBlank(expr);
	}
	else
	{
		negative = false;
	}

	const char *start = expr;
	while (*expr == '.' || isdigit(*expr))
	{
		if (*expr == '.') hasPoint = true;
		++ expr;
	}
	if (start == expr) return NULL;
	if (!hasPoint)
	{
		sint64 value = 0;
		// this is an integer
		for (const char *nbPtr = start; nbPtr < expr; ++ nbPtr)
		{
			value *= 10;
			value += (sint64) (*nbPtr - '0');
		}
		setInteger(negative ? - value : value);
		return expr;
	}
	else // floating point value : use scanf
	{
		// well, for now, we only parse a float
		float value;
		std::string floatValue(start, expr - start);
		if (fromString(floatValue, value))
		{
			setDouble(negative ? - value : value);
			return expr;
		}
		else
		{
			return NULL;
		}
	}
}

//==================================================================
const char *CInterfaceExprValue::evalString(const char *expr)
{
	expr = skipBlank(expr);
	if (*expr != '\'') return NULL;
	++expr;
	std::string str;
	for (;;)
	{
		if (expr == '\0')
		{
			nlwarning("CInterfaceExprValue::evalString : end of buffer encountered in a string");
			return NULL;
		}
		else
		if (*expr == '\'')
		{
			++ expr;
			break;
		}
		if (*expr == '\\') // special char
		{
			++ expr;
			switch (*expr)
			{
				case 't': str  += '\t'; break;
				case 'r': str  += '\r'; break;
				case 'n': str  += '\n'; break;
				case '\'': str += '\''; break;
				case '"': str  += '"'; break;
				case '\\': str += '\\'; break;
				case '\n':
				case '\r':
					// string continue on next line, so do nothing
				break;
				case '\0': continue;
				default:
					nlwarning("CInterfaceExprValue::evalString : unknown escape sequence : \\%c", *expr);
					if (*expr) str += *expr;
				break;
			}
		}
		else if (*expr == '\n' || *expr == '\r')
		{
			nlwarning("CInterfaceExprValue::evalString : line break encountered in a string");
			return NULL;
		}
		else
		{
			str += *expr;
		}
		++ expr;
	}
	setString(str);
	return expr;
}

//==================================================================
bool CInterfaceExprValue::toType(TType type)
{
	switch(type)
	{
		case Boolean: return toBool();
		case Integer: return toInteger();
		case Double:  return toDouble();
		case String:  return toString();
		case RGBA:	  return toRGBA();
		default: return false;
	}
}


//==================================================================
void CInterfaceExprValue::clean()
{
	switch (_Type)
	{
		case String:   _StringValue.clear(); break;
		case UserType: delete _UserTypeValue; break;
		default: break;
	}
}

//==================================================================
void CInterfaceExprValue::setUserType(CInterfaceExprUserType *value)
{
	if (_Type == UserType && value == _UserTypeValue) return;
	clean();
	_Type = UserType;
	_UserTypeValue = value;
}

//==================================================================
bool CInterfaceExprValue::getBool() const
{
	if (_Type != Boolean)
	{
		nlwarning("<CInterfaceExprValue::getBool> bad type!");
		return false;
	}
	return _BoolValue;
}

//==================================================================
sint64 CInterfaceExprValue::getInteger() const
{
	if (_Type != Integer)
	{
		nlwarning("<CInterfaceExprValue::getInteger> bad type!");
		return 0;
	}
	return _IntegerValue;
}

//==================================================================
double CInterfaceExprValue::getDouble() const
{
	if (_Type != Double)
	{
		nlwarning("<CInterfaceExprValue::getDouble> bad type!");
		return 0;
	}
	return _DoubleValue;
}

//==================================================================
std::string CInterfaceExprValue::getString() const
{
	if (_Type != String)
	{
		nlwarning("<CInterfaceExprValue::getString> bad type!");
		return "";
	}
	return _StringValue.toString();
}

//==================================================================
NLMISC::CRGBA CInterfaceExprValue::getRGBA() const
{
	if (_Type != RGBA)
	{
		nlwarning("<CInterfaceExprValue::getRGBA> bad type!");
		return CRGBA::White;
	}
	NLMISC::CRGBA col;
	col.R = (uint8)(_RGBAValue&0xff);
	col.G = (uint8)((_RGBAValue>>8)&0xff);
	col.B = (uint8)((_RGBAValue>>16)&0xff);
	col.A = (uint8)((_RGBAValue>>24)&0xff);
	return col;
}


//==================================================================
const ucstring &CInterfaceExprValue::getUCString() const
{
	if (_Type != String)
	{
		nlwarning("<CInterfaceExprValue::getString> bad type!");
		static ucstring emptyString;
		return emptyString;
	}
	return _StringValue;
}

//==================================================================
CInterfaceExprUserType *CInterfaceExprValue::getUserType() const
{
	if (_Type != UserType)
	{
		nlwarning("<CInterfaceExprValue::getUserType> bad type!");
		return NULL;
	}
	return _UserTypeValue;
}

//==================================================================
CInterfaceExprValue::CInterfaceExprValue(const CInterfaceExprValue &other) : _Type(NoType)
{
	*this = other;
}

//==================================================================
CInterfaceExprValue &CInterfaceExprValue::operator = (const CInterfaceExprValue &other)
{
	if (this != &other)
	{
		clean();
		switch(other._Type)
		{
			case Boolean:  _BoolValue    = other._BoolValue;    break;
			case Integer:  _IntegerValue = other._IntegerValue; break;
			case Double:   _DoubleValue  = other._DoubleValue;  break;
			case String:   _StringValue  = other._StringValue;  break;
			case RGBA:	   _RGBAValue    = other._RGBAValue;    break;
			case UserType:
				if (other._UserTypeValue != NULL)
				{
					_UserTypeValue = other._UserTypeValue->clone();
				}
				else
				{
					_UserTypeValue = NULL;
				}
			break;
			case NoType: break;
			default:
				nlwarning("<CInterfaceExprValue::operator=> bad source type") ;
				return *this;
			break;
		}
		_Type = other._Type;
	}
	return *this;
}