private IFormat ParseExpression(string str)
{
List <IFormat> operands = new List <IFormat>();
LatexLexems ll = LatexLexems.getInstance();
foreach (var def in ll.getDefinitionsLexem())
{
if (matches(str, def.getRegex()))
{
IFormat name = ParseExpression(getTokenValue(str, def.getRegex(), "name"));
IFormat value = ParseExpression(getTokenValue(str, def.getRegex(), "expr"));
operands.Add(name);
operands.Add(value);
return(new Latex(def.getType(), operands, null));
}
}
if ((operands = ParseMultiOperandsExpression(str, '+')) != null)
{
return(new Latex(Types.Addition, operands, null));
}
if ((operands = ParseMultiOperandsExpression(str, '-')) != null)
{
return(new Latex(Types.Substraction, operands, null));
}
if ((operands = ParseMultiOperandsExpression(str, '*')) != null)
{
return(new Latex(Types.Multiplication, operands, null));
}
operands = new List <IFormat>();
string[] strings;
Lexem tmp = new Lexem(Types.Variable, "");
int length = 0;
foreach (var def in ll.getOperandsLexem())
{
Regex rgx = new Regex(def.getRegex());
Match match = rgx.Match(str);
if (match.Length > length)
{
tmp = def;
length = match.Length;
}
}
if (tmp.getRegex() == "")
{
throw new Exception("Bad input, really! Follow the syntax");
}
switch (tmp.getType())
{
case Types.Variable:
return(new Latex(str));
case Types.Number:
return(new Latex(Convert.ToDouble(str)));
case Types.Interval:
case Types.List:
{
str = str.Substring(1, str.Length - 2);
strings = str.Split(';');
foreach (var s in strings)
{
operands.Add(ParseExpression(s));
}
return(new Latex(tmp.getType(), operands, null));
}
case Types.FuncExpression:
IFormat funcName = ParseExpression(getTokenValue(str, tmp.getRegex(), "fr"));
string parametrs = getTokenValue(str, tmp.getRegex(), "sec");
parametrs = parametrs.Substring(1, parametrs.Length - 2);
strings = parametrs.Split(',');
foreach (var s in strings)
{
operands.Add(ParseExpression(s));
}
return(new Latex(tmp.getType(), operands, funcName));
}
IFormat first = ParseExpression(getTokenValue(str, tmp.getRegex(), "fr"));
IFormat second = ParseExpression(getTokenValue(str, tmp.getRegex(), "sec"));
operands.Add(first);
operands.Add(second);
return(new Latex(tmp.getType(), operands, null));
}