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public Append ( IExpressionElement element ) : |
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| element | IExpressionElement | |
| return | ||
private static void ProcessRightParenth(Expression e, Stack <FuncData> tmpStack, int pos)
{
if (tmpStack.Count == 0)
{
throw new ArgumentException("unmatching right parenthesis at " + pos);
}
while (tmpStack.Peek().SpecialKind != SpecialOperandKind.LeftParenthesis)
{
e.Append(tmpStack.Pop().Func);
if (tmpStack.Count == 0)
{
throw new ArgumentException("unmatching right parenthesis at " + pos);
}
}
tmpStack.Pop(); //remove left parenthesis
while (tmpStack.Count > 0 && tmpStack.Peek().IsFunctionOrUnary) //append function/unary minus or both
{
e.Append(tmpStack.Pop().Func);
}
}
private static void ProcessComma(Expression e, Stack <FuncData> tmpStack, int pos)
{
if (tmpStack.Count == 0)
{
throw new ArgumentException("comma without left parenthesis at " + pos);
}
while (tmpStack.Peek().SpecialKind != SpecialOperandKind.LeftParenthesis)
{
e.Append(tmpStack.Pop().Func);
if (tmpStack.Count == 0)
{
throw new ArgumentException("comma without left parenthesis at " + pos);
}
}
}
private static void ProcessOperator(FuncData op, Expression e, Stack <FuncData> tmpStack)
{
while (tmpStack.Count > 0) //while operators with higher or equal precedence
{
FuncData fd = tmpStack.Peek();
if (fd.SpecialKind == SpecialOperandKind.NotSpecial && !fd.IsFunctionOrUnary && fd.Precedence >= op.Precedence)
{
e.Append(tmpStack.Pop().Func);
}
else
{
break;
}
}
tmpStack.Push(op);
}
public static Expression Parse(string expression, IEnumerable <string> vars)
{
expression.ToLower();
int pos = 0;
Stack <FuncData> tmpStack = new Stack <FuncData>();
Expression e = new Expression(vars);
bool noBOperatorExpected = true;
bool lParenthExpected = false;
while (pos < expression.Length)
{
string term = ReadTerm(expression, ref pos);
if (lParenthExpected && term != "(")
{
throw new ArgumentException("expected '(' at " + pos);
}
lParenthExpected = false; //checked, can be turn off
//if a number or const or variable, append to the expression
double num;
if (double.TryParse(term, out num)) //number
{
e.Append(new Variable()
{
Value = num, Name = num.ToString()
});
noBOperatorExpected = false;
continue;
}
IExpressionElement el;
if (_consts.TryGetValue(term, out el)) //const
{
e.Append(el);
noBOperatorExpected = false;
continue;
}
Variable v;
if (e.Vars.TryGetValue(term, out v)) //variable
{
e.Append(v);
noBOperatorExpected = false;
continue;
}
//if function -> push to stack
FuncData fd;
if (_functions.TryGetValue(term, out fd))
{
tmpStack.Push(fd);
lParenthExpected = true; //dont need to set/reset noBOperatorExpected
continue;
}
if (term.Length == 1) //operators
{
char termch = term[0];
if (_soperators.TryGetValue(termch, out fd))
{
switch (fd.SpecialKind)
{
case SpecialOperandKind.LeftParenthesis:
tmpStack.Push(fd);
noBOperatorExpected = true;
break;
case SpecialOperandKind.RightParenthesis:
noBOperatorExpected = false;
ProcessRightParenth(e, tmpStack, pos);
break;
case SpecialOperandKind.Comma:
noBOperatorExpected = true;
ProcessComma(e, tmpStack, pos);
break;
}
continue;
}
if (noBOperatorExpected)
{
if (_uoperators.TryGetValue(termch, out fd))
{
tmpStack.Push(fd);
//noBOperatorExpected = true; - is already
continue;
}
}
else
{
if (_operators.TryGetValue(termch, out fd))
{
ProcessOperator(fd, e, tmpStack);
noBOperatorExpected = true;
continue;
}
}
}
//unrecongnizable
throw new ArgumentException("unrecognizable term " + term + " at before " + pos);
}
//we will be tolerant to closing parenthesis, i.e. the left parenthesis left will be ignored
foreach (var f in tmpStack)
{
if (f.SpecialKind != SpecialOperandKind.LeftParenthesis)
{
e.Append(f.Func);
}
else
{
throw new ArgumentException("unmatching parenthesis");
}
}
return(e);
}
private static void ProcessOperator(FuncData op, Expression e, Stack<FuncData> tmpStack)
{
while (tmpStack.Count>0) //while operators with higher or equal precedence
{
FuncData fd = tmpStack.Peek();
if (fd.SpecialKind == SpecialOperandKind.NotSpecial && !fd.IsFunctionOrUnary && fd.Precedence >= op.Precedence)
e.Append(tmpStack.Pop().Func);
else
break;
}
tmpStack.Push(op);
}
private static void ProcessRightParenth(Expression e, Stack<FuncData> tmpStack, int pos)
{
if (tmpStack.Count == 0)
throw new ArgumentException("unmatching right parenthesis at " + pos);
while (tmpStack.Peek().SpecialKind != SpecialOperandKind.LeftParenthesis)
{
e.Append(tmpStack.Pop().Func);
if (tmpStack.Count == 0)
throw new ArgumentException("unmatching right parenthesis at " + pos);
}
tmpStack.Pop(); //remove left parenthesis
while (tmpStack.Count > 0 && tmpStack.Peek().IsFunctionOrUnary) //append function/unary minus or both
e.Append(tmpStack.Pop().Func);
}
private static void ProcessComma(Expression e, Stack<FuncData> tmpStack, int pos)
{
if (tmpStack.Count==0)
throw new ArgumentException("comma without left parenthesis at " + pos);
while (tmpStack.Peek().SpecialKind!=SpecialOperandKind.LeftParenthesis)
{
e.Append(tmpStack.Pop().Func);
if (tmpStack.Count == 0)
throw new ArgumentException("comma without left parenthesis at " + pos);
}
}
public static Expression Parse(string expression, IEnumerable<string> vars)
{
expression.ToLower();
int pos = 0;
Stack<FuncData> tmpStack=new Stack<FuncData>();
Expression e=new Expression(vars);
bool noBOperatorExpected = true;
bool lParenthExpected = false;
while (pos<expression.Length)
{
string term = ReadTerm(expression, ref pos);
if (lParenthExpected && term!="(")
throw new ArgumentException("expected '(' at "+pos);
lParenthExpected = false; //checked, can be turn off
//if a number or const or variable, append to the expression
double num;
if (double.TryParse(term, out num)) //number
{
e.Append(new Variable() {Value = num, Name=num.ToString()});
noBOperatorExpected = false;
continue;
}
IExpressionElement el;
if (_consts.TryGetValue(term, out el)) //const
{
e.Append(el);
noBOperatorExpected = false;
continue;
}
Variable v;
if (e.Vars.TryGetValue(term, out v)) //variable
{
e.Append(v);
noBOperatorExpected = false;
continue;
}
//if function -> push to stack
FuncData fd;
if (_functions.TryGetValue(term, out fd))
{
tmpStack.Push(fd);
lParenthExpected = true; //dont need to set/reset noBOperatorExpected
continue;
}
if (term.Length == 1) //operators
{
char termch = term[0];
if (_soperators.TryGetValue(termch, out fd))
{
switch (fd.SpecialKind)
{
case SpecialOperandKind.LeftParenthesis:
tmpStack.Push(fd);
noBOperatorExpected = true;
break;
case SpecialOperandKind.RightParenthesis:
noBOperatorExpected = false;
ProcessRightParenth(e, tmpStack, pos);
break;
case SpecialOperandKind.Comma:
noBOperatorExpected = true;
ProcessComma(e, tmpStack, pos);
break;
}
continue;
}
if (noBOperatorExpected)
{
if (_uoperators.TryGetValue(termch, out fd))
{
tmpStack.Push(fd);
//noBOperatorExpected = true; - is already
continue;
}
}
else
{
if(_operators.TryGetValue(termch, out fd))
{
ProcessOperator(fd, e, tmpStack);
noBOperatorExpected = true;
continue;
}
}
}
//unrecongnizable
throw new ArgumentException("unrecognizable term " + term + " at before " + pos);
}
//we will be tolerant to closing parenthesis, i.e. the left parenthesis left will be ignored
foreach (var f in tmpStack)
if (f.SpecialKind!=SpecialOperandKind.LeftParenthesis)
e.Append(f.Func);
else
throw new ArgumentException("unmatching parenthesis");
return e;
}
