public static IExpression BuildExpression(List <Token> tokens, ref int index, Stack <int?> precedenceStack)
{
if (index >= tokens.Count)
{
throw new TokenParserException("The script seems to have ended prematurely while I was doing calculations. Shouldn't there be something here?", tokens[tokens.Count - 1]);
}
Token token = tokens[index];
IExpression expr = null;
switch (token.TokenType)
{
case TokenType.Number:
case TokenType.StringLiteral:
expr = BuildSingularExpression(tokens, ref index);
break;
case TokenType.Word:
if (token.Value == "true" || token.Value == "false")
{
expr = new BooleanExpression();
expr.BuildExpression(tokens, ref index, precedenceStack);
}
else
{
expr = BuildWordExpression(tokens, ref index, precedenceStack);
}
break;
//case TokenType.GroupStart:
// expr = BuildGroupedExpression(tokens, ref index);
// break;
default:
throw new TokenParserException("This part of the script should equate to a value but instead I got \"" + token.Value + "\", which doesn't really mean anything in this context.", token);
}
int?precedence = precedenceStack.Peek();
while (NextHasGreaterPrecedence(precedence, tokens, index))
{
expr = BuildBinaryExpression(tokens, ref index, expr, precedenceStack);
}
return(expr);
}
public static IExpression BuildExpression(List<Token> tokens, ref int index, Stack<int?> precedenceStack)
{
if (index >= tokens.Count)
throw new TokenParserException("The script seems to have ended prematurely while I was doing calculations. Shouldn't there be something here?", tokens[tokens.Count - 1]);
Token token = tokens[index];
IExpression expr = null;
switch (token.TokenType)
{
case TokenType.Number:
case TokenType.StringLiteral:
expr = BuildSingularExpression(tokens, ref index);
break;
case TokenType.Word:
if (token.Value == "true" || token.Value == "false")
{
expr = new BooleanExpression();
expr.BuildExpression(tokens, ref index, precedenceStack);
}
else
expr = BuildWordExpression(tokens, ref index, precedenceStack);
break;
//case TokenType.GroupStart:
// expr = BuildGroupedExpression(tokens, ref index);
// break;
default:
throw new TokenParserException("This part of the script should equate to a value but instead I got \"" + token.Value + "\", which doesn't really mean anything in this context.", token);
}
int? precedence = precedenceStack.Peek();
while (NextHasGreaterPrecedence(precedence, tokens, index))
expr = BuildBinaryExpression(tokens, ref index, expr, precedenceStack);
return expr;
}
