/// <summary>
/// 重新构造二叉树
/// </summary>
/// <param name="strExpression">表达式</param>
public void ChangeExpression(string strExpression)
{
_Expression = strExpression;
_Tree = null;
_Position = 0;
_Identifiers = null;
_CurrentIdentifier = null;
_ParentIdentifier = null;
if (strExpression != string.Empty)
{
try
{
_ExpressionChars = new Char[strExpression.Length + 1];
strExpression.CopyTo(0, _ExpressionChars, 0, strExpression.Length);
_ExpressionChars[strExpression.Length] = '\0';
_Tree = DoExpression();
if (_ExpressionChars[_Position] != '\0')
{
throw ParsingException.NewParsingException(Parse_Error.peSyntaxError, _Position);
}
}
finally
{
_CurrentIdentifier = null;
_ParentIdentifier = null;
}
}
}
private void CheckOperand(object p1, object p2, int nPos)
{
if (p1 == null || p2 == null)
{
throw ParsingException.NewParsingException(Parse_Error.peNeedOperand, nPos);
}
}
/// <summary>
/// 处理各种系数、负数、括号等
/// </summary>
/// <returns></returns>
private EXP_TreeNode DoFactor()
{
EXP_TreeNode node = null;
EXP_TreeNode left = null;
EXP_TreeNode node2 = null;
SkipSpaces();
char ch = _ExpressionChars[_Position];
int nPos = _Position;
if (ch == '-') //处理负号
{
OutputID(Operation_IDs.OI_NEG, "-", _Position);
_Position++;
node2 = DoExpression();
left = NewTreeNode();
left._OperationID = Operation_IDs.OI_NEG;
left._Value = (double)-1;
left._Position = nPos;
node = NewTreeNode(left, node2, Operation_IDs.OI_MUL, nPos);
}
else
if (ch == '(')
{
OutputID(Operation_IDs.OI_LBRACKET, "(", _Position);
_Position++;
node = DoExpression();
SkipSpaces();
if (_ExpressionChars[_Position] != ')')
{
throw ParsingException.NewParsingException(Parse_Error.peCharExpected, _Position, ")");
}
else
{
OutputID(Operation_IDs.OI_RBRACKET, ")", _Position);
}
_Position++;
}
else
{
node = DoIdentifier();
}
SkipSpaces();
return(node);
}
private EXP_TreeNode DoString()
{
int nPos = _Position;
char ch = _ExpressionChars[++_Position];
StringBuilder strB = new StringBuilder(256);
StringBuilder strIDB = new StringBuilder(256);
strIDB.Append('"');
while (ch != '\0')
{
if (ch != '"')
{
strB.Append(ch);
strIDB.Append(ch);
_Position++;
}
else
if (_ExpressionChars[_Position + 1] == '"')
{
strB.Append('"');
strIDB.Append("\"\"");
_Position += 2;
}
else
{
strIDB.Append('"');
_Position++;
break;
}
ch = _ExpressionChars[_Position];
}
if (ch == '\0')
{
throw ParsingException.NewParsingException(Parse_Error.peCharExpected, _Position, "\"");
}
string strID = strIDB.ToString();
OutputID(Operation_IDs.OI_STRING, strID, nPos);
EXP_TreeNode node = NewTreeNode();
node._Position = nPos;
node._OperationID = Operation_IDs.OI_STRING;
node._Value = strB.ToString();
return(node);
}
private EXP_TreeNode DoDatetime()
{
int nPos = _Position;
char ch = _ExpressionChars[++_Position];
StringBuilder strB = new StringBuilder(256);
strB.Append("#");
while (ch != '\0')
{
strB.Append(ch);
if (ch == '#')
{
_Position++;
break;
}
ch = _ExpressionChars[++_Position];
}
if (ch == '\0')
{
throw ParsingException.NewParsingException(Parse_Error.peCharExpected, _Position, "#");
}
EXP_TreeNode node = NewTreeNode();
node._Position = nPos;
node._OperationID = Operation_IDs.OI_DATETIME;
try
{
string strID = strB.ToString();
node._Value = DateTime.Parse(strID);
OutputID(Operation_IDs.OI_DATETIME, strID, nPos);
return(node);
}
catch (System.FormatException)
{
throw ParsingException.NewParsingException(Parse_Error.peFormatError, nPos);
}
}
/// <summary>
/// 处理各种数字、标识符、自定义函数、字符串等
/// </summary>
/// <returns></returns>
private EXP_TreeNode DoIdentifier()
{
EXP_TreeNode result = null;
SkipSpaces();
char ch = _ExpressionChars[_Position];
if (ch != '\0')
{
if (ch == '#') //string
{
result = DoDatetime();
}
else
if (ch == '"') //string
{
result = DoString();
}
else
if (Char.IsDigit(ch) || ch == '.')
{
result = DoNumber();
}
else
if (Char.IsLetter(ch) || ch == '_')
{
result = DoFunctionID();
}
else
{
throw ParsingException.NewParsingException(Parse_Error.peInvalidOperator, _Position, ch.ToString());
}
SkipSpaces();
}
return(result);
}
private object VExp(EXP_TreeNode node)
{
object oValue = null;
if (node != null)
{
try
{
switch (node._OperationID)
{
case Operation_IDs.OI_NUMBER:
case Operation_IDs.OI_STRING:
case Operation_IDs.OI_NEG:
case Operation_IDs.OI_BOOLEAN:
case Operation_IDs.OI_DATETIME:
oValue = node._Value;
break;
case Operation_IDs.OI_ADD:
oValue = AddOP(VExp(node._Left), VExp(node._Right), node._Position);
break;
case Operation_IDs.OI_MINUS:
{
object p1 = VExp(node._Left);
object p2 = VExp(node._Right);
CheckOperand(p1, p2, node._Position);
oValue = (double)p1 - (double)p2;
}
break;
case Operation_IDs.OI_MUL:
{
object p1 = VExp(node._Left);
object p2 = VExp(node._Right);
CheckOperand(p1, p2, node._Position);
oValue = (double)p1 * (double)p2;
}
break;
case Operation_IDs.OI_DIV:
{
object p1 = VExp(node._Left);
object p2 = VExp(node._Right);
CheckOperand(p1, p2, node._Position);
oValue = (double)p1 / (double)p2;
}
break;
case Operation_IDs.OI_LOGICAL_OR:
{
oValue = (bool)VExp(node._Left);
object oRight = (bool)false;
if (Optimize == false || (bool)oValue == false)
{
oRight = VExp(node._Right);
}
CheckOperand(oValue, oRight, node._Position);
oValue = (bool)oValue || (bool)oRight;
}
break;
case Operation_IDs.OI_LOGICAL_AND:
{
oValue = (bool)VExp(node._Left);
object oRight = (bool)true;
if (Optimize == false || (bool)oValue == true)
{
oRight = VExp(node._Right);
}
CheckOperand(oValue, oRight, node._Position);
oValue = (bool)oValue && (bool)oRight;
}
break;
case Operation_IDs.OI_NOT:
oValue = VExp(node._Right);
CheckOperand(oValue, node._Position);
oValue = !(bool)oValue;
break;
case Operation_IDs.OI_GREAT:
oValue = CompareGreatOP(VExp(node._Left), VExp(node._Right), node._Position);
break;
case Operation_IDs.OI_GREATEQUAL:
oValue = CompareGreatEqualOP(VExp(node._Left), VExp(node._Right), node._Position);
break;
case Operation_IDs.OI_LESS:
oValue = CompareLessOP(VExp(node._Left), VExp(node._Right), node._Position);
break;
case Operation_IDs.OI_LESSEQUAL:
oValue = CompareLessEqualOP(VExp(node._Left), VExp(node._Right), node._Position);
break;
case Operation_IDs.OI_NOT_EQUAL:
oValue = CompareNotEqualOP(VExp(node._Left), VExp(node._Right), node._Position);
break;
case Operation_IDs.OI_EQUAL:
oValue = CompareEqualOP(VExp(node._Left), VExp(node._Right), node._Position);
break;
case Operation_IDs.OI_USERDEFINE:
if (UserFunctions != null)
{
ParamObject[] po = GetParamArray(node._Params);
oValue = UserFunctions.CalculateUserFunction(node._FunctionName, po, this);
}
break;
default: throw ParsingException.NewParsingException(Parse_Error.peInvalidOperator, node._Position);
}
}
catch (System.InvalidCastException)
{
throw ParsingException.NewParsingException(Parse_Error.peTypeMismatch, node._Position);
}
}
return(oValue);
}
EXP_TreeNode GetFunctionNode(Operation_IDs funcID, string strID)
{
EXP_TreeNode node = null;
EXP_TreeNode nodeTemp = null;
ArrayList paramBase = null;
int nStartFunction = _Position - strID.Length;
OutputID(Operation_IDs.OI_USERDEFINE, strID, nStartFunction);
if (_ExpressionChars[_Position] == '(') //有参数
{
OutputIDToSubLevel();
OutputID(Operation_IDs.OI_LBRACKET, "(", _Position);
do
{
_Position++;
SkipSpaces();
nodeTemp = DoExpression();
if (nodeTemp != null)
{
if (paramBase == null)
{
paramBase = new ArrayList(4);
}
paramBase.Add(nodeTemp);
SkipSpaces();
}
else
{
break;
}
if (_ExpressionChars[_Position] == ',')
{
OutputID(Operation_IDs.OI_COMMA, ",", _Position);
}
}while (_ExpressionChars[_Position] == ',');
if (_ExpressionChars[_Position] == ')')
{
OutputID(Operation_IDs.OI_RBRACKET, ")", _Position);
OutputIDToParentLevel();
_Position++;
node = NewTreeNode();
node._Position = nStartFunction;
node._Params = paramBase;
node._OperationID = funcID;
if (funcID == Operation_IDs.OI_USERDEFINE)
{
node._FunctionName = strID;
}
}
else
{
throw ParsingException.NewParsingException(Parse_Error.peCharExpected, _Position, ")");
}
SkipSpaces();
}
else //没有参数
{
node = NewTreeNode();
node._Position = nStartFunction;
node._Params = paramBase;
node._OperationID = funcID;
if (funcID == Operation_IDs.OI_USERDEFINE)
{
node._FunctionName = strID;
}
}
return(node);
}
/// <summary>
/// 逻辑比较运算
/// </summary>
/// <returns></returns>
private EXP_TreeNode DoLogicalOP()
{
EXP_TreeNode node = null;
EXP_TreeNode node1 = DoAddSub();
EXP_TreeNode node2 = null;
char op = _ExpressionChars[_Position];
string strID = "";
while (op == '>' || op == '<' || op == '=')
{
int nPos = _Position;
Operation_IDs oID = Operation_IDs.OI_NONE;
if (_ExpressionChars[++_Position] == '=')
{
switch (op)
{
case '>': //>=
oID = Operation_IDs.OI_GREATEQUAL;
strID = ">=";
break;
case '<': //<=
oID = Operation_IDs.OI_LESSEQUAL;
strID = "<=";
break;
case '=': //==
oID = Operation_IDs.OI_EQUAL;
strID = "==";
break;
default: throw ParsingException.NewParsingException(Parse_Error.peInvalidOperator,
_Position, op.ToString());
}
_Position++;
}
else
{
if (_ExpressionChars[_Position] == '>')
{
if (op == '<') //<>
{
strID = "<>";
oID = Operation_IDs.OI_NOT_EQUAL;
_Position++;
}
else
{
throw ParsingException.NewParsingException(Parse_Error.peInvalidOperator,
_Position, op.ToString());
}
}
else
{
switch (op)
{
case '>': oID = Operation_IDs.OI_GREAT;
strID = ">";
break;
case '<': oID = Operation_IDs.OI_LESS;
strID = "<";
break;
}
}
}
OutputID(oID, strID, nPos);
node2 = DoAddSub();
node = NewTreeNode(node1, node2, oID, nPos);
node1 = node;
op = _ExpressionChars[_Position];
}
return(node1);
}
