internal static int GetNextToken(string source, int position, out Token token, Token prevToken = null)
{
char symbol = source[position];
token = null;
if (DoubleToken.IsStartSymbol(symbol))
{
token = new DoubleToken().FromString(source, ref position);
return position;
}
if (BracketToken.IsStartSymbol(symbol))
{
token = BracketToken.GetBracket(symbol, prevToken);
return position + 1;
}
if (OperationToken.TryGetOperation(symbol, prevToken, out token))
{
return position + 1;
}
if (FunctionToken.IsStartSymbol(symbol))
{
token = new FunctionToken().FromString(source, ref position);
return position;
}
throw new ArgumentOutOfRangeException("symbol", symbol, "Unexpected symbol");
}
public void TestMethod_NewFunctionToken()
{
string function = "exp";
int position = 0;
var token = new FunctionToken().FromString(function, ref position) as FunctionToken;
Assert.AreEqual(1, token.Arity, "Arity for 'exp' function should be '1'");
}
