public static Expression Compile(string exp)
{
var functions = new FunctionManager();
return(Compile(Tokenize(exp), functions));
}
private static Expression InternalCompile(LinkedListNode <Token> first, LinkedListNode <Token> last, FunctionManager functions, int level = 0)
{
if (first.Value.Type == TokenType.SBracket && MatchingBracketForward(first) == last)
{
return(InternalCompile(first.Next, last.Previous, functions, 0));
}
LinkedListNode <Token> token;
int brackets = 0;
switch (level)
{
case 0:
Debug.Assert(level == 0);
// Additions and subtractions
token = last;
while (token != first.Previous)
{
if (token.Value.Type == TokenType.SBracket)
{
brackets--;
}
else if (token.Value.Type == TokenType.EBracket)
{
brackets++;
}
else if (brackets == 0)
{
if (token.Value.Value == "+")
{
return(functions.Operator("+").Create(InternalCompile(first, token.Previous, functions, level), InternalCompile(token.Next, last, functions, level)));
}
if (token.Value.Value == "-")
{
return(functions.Operator("-").Create(InternalCompile(first, token.Previous, functions, level), InternalCompile(token.Next, last, functions, level)));
}
}
else if (brackets <= 0)
{
throw new Exception("SumTingWong. Tokens: " + ContainerUtils.AsString(first, last));
}
token = token.Previous;
}
Debug.Assert(brackets == 0, "Unbalanced brackets");
level++;
goto case 1;
case 1:
Debug.Assert(level == 1);
// Multiplications and divisions
token = last;
while (token != first.Previous)
{
if (token.Value.Type == TokenType.SBracket)
{
brackets--;
}
else if (token.Value.Type == TokenType.EBracket)
{
brackets++;
}
else if (brackets == 0)
{
if (token.Value.Value == "*")
{
return(functions.Operator("*").Create(InternalCompile(first, token.Previous, functions, level), InternalCompile(token.Next, last, functions, level)));
}
if (token.Value.Value == "/")
{
return(functions.Operator("/").Create(InternalCompile(first, token.Previous, functions, level), InternalCompile(token.Next, last, functions, level)));
}
}
else if (brackets <= 0)
{
throw new Exception("SumTingWong. Tokens: " + ContainerUtils.AsString(first, last));
}
token = token.Previous;
}
if (brackets != 0)
{
throw new Exception("Unbalanced brackets");
}
level++;
goto case 2;
case 2:
Debug.Assert(level == 2);
// Powers
token = last;
while (token != first.Previous)
{
if (token.Value.Type == TokenType.SBracket)
{
brackets--;
}
else if (token.Value.Type == TokenType.EBracket)
{
brackets++;
}
else if (brackets == 0)
{
if (token.Value.Value == "^")
{
return(functions.Operator("^").Create(InternalCompile(first, token.Previous, functions, level), InternalCompile(token.Next, last, functions, level)));
}
}
else if (brackets <= 0)
{
throw new Exception("SumTingWong. Tokens: " + ContainerUtils.AsString(first, last));
}
token = token.Previous;
}
if (brackets != 0)
{
throw new Exception("Unbalanced brackets");
}
level++;
goto case 3;
case 3:
Debug.Assert(level == 3);
// Functions & variables
token = last;
while (token != first.Previous)
{
if (token.Value.Type == TokenType.SBracket)
{
brackets--;
}
else if (token.Value.Type == TokenType.EBracket)
{
brackets++;
}
else if (brackets == 0)
{
if (token.Value.Type == TokenType.Identifier)
{
if (token.Next != null && token.Next.Value.Type == TokenType.SBracket)
{
return(functions.Function(token.Value.Value).Create(FunctionArgumentsCompile(token.Next.Next, MatchingBracketForward(token.Next), functions)));
}
else
{
return(new Variable(token.Value.Value));
}
}
}
else if (brackets <= 0)
{
throw new Exception("SumTingWong. Tokens: " + ContainerUtils.AsString(first, last));
}
token = token.Previous;
}
if (brackets != 0)
{
throw new Exception("Unbalanced brackets");
}
level++;
goto case 4;
case 4:
Debug.Assert(level == 4);
// Literals
token = last;
while (token != first.Previous)
{
if (token.Value.Type == TokenType.SBracket)
{
brackets--;
}
else if (token.Value.Type == TokenType.EBracket)
{
brackets++;
}
else if (brackets == 0)
{
if (token.Value.Type == TokenType.Value)
{
return(new ValueExpression(double.Parse(token.Value.Value)));
}
}
else if (brackets <= 0)
{
throw new Exception("SumTingWong. Tokens: " + ContainerUtils.AsString(first, last));
}
token = token.Previous;
}
if (brackets != 0)
{
throw new Exception("Unbalanced brackets");
}
//level++;
goto default;
default:
throw new Exception();
}
}
private static Expression[] FunctionArgumentsCompile(LinkedListNode <Token> first, LinkedListNode <Token> last, FunctionManager functions)
{
LinkedListNode <Token> prevComma = first; // Actually just after the previous comma.
LinkedListNode <Token> token = first;
List <Expression> exps = new List <Expression>();
int brackets = 0;
while (token != last)
{
if (token.Value.Type == TokenType.SBracket)
{
brackets--;
}
else if (token.Value.Type == TokenType.EBracket)
{
brackets++;
}
else if (brackets == 0 && token.Value.Type == TokenType.Comma)
{
exps.Add(InternalCompile(prevComma, token.Previous, functions));
prevComma = token.Next;
}
token = token.Next;
}
Debug.Assert(brackets == 0);
exps.Add(InternalCompile(prevComma, last.Previous, functions));
return(exps.ToArray());
}
public static Expression Compile(LinkedList <Token> tokens, FunctionManager functions)
{
return(InternalCompile(tokens.First, tokens.Last, functions));
}