public IEnumerable<SemanticToken> ApplySemantics(IEnumerable<Token> tokenStream)
{
var tokens = tokenStream.ToList();
PreprocessSemantics(ref tokens);
var rv = new List<SemanticToken>(tokens.Count());
foreach (var token in tokens)
{
if (token.OperationType == OperationType.Operator)
{
var t = OperatorToOpcode(token);
rv.Add(t);
}
else
{
switch (token.TokenType)
{
case TokenType.FunctionCall:
{
var t = new SemanticToken
{
TokenType = token.TokenType,
OperationType = OperationType.FunctionCall,
Precedence = 9
};
var function = m_HostCallTable.GetFunctionByName(token.TokenValue);
t.Data = function.Id;
rv.Add(t);
break;
}
case TokenType.FunctionArgumentSeperator:
{
rv.Add(new SemanticToken { TokenType = token.TokenType, OperationType = OperationType.Operand });
break;
}
case TokenType.Symbol:
{
var symbol = HostSymbolTable.GetSymbolByName(token.TokenValue);
rv.Add(new SemanticToken { TokenType = token.TokenType, OperationType = OperationType.Operator, Data = symbol.SymbolId, Precedence = 9});
break;
}
default:
{
var t = new SemanticToken
{
TokenType = token.TokenType,
OperationType = OperationType.Operand
};
if (!t.IsBracket())
t.Data = Double.Parse(token.TokenValue);
rv.Add(t);
break;
}
}
}
}
return rv;
}
private static SemanticToken OperatorToOpcode(Token token)
{
var t = new SemanticToken() { TokenType = token.TokenType, OperationType = token.OperationType };
switch (t.TokenType)
{
case TokenType.Add:
t.Precedence = 6;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.Subtract:
t.Precedence = 6;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.Multiply:
t.Precedence = 7;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.Divide:
t.Precedence = 7;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.PowerOf:
t.Precedence = 7;
t.OperatorAssociativity = OperatorAssociativity.Right;
break;
case TokenType.UnaryMinus:
t.Precedence = 8;
t.OperatorAssociativity = OperatorAssociativity.Right;
break;
case TokenType.Negation:
t.Precedence = 8;
t.OperatorAssociativity = OperatorAssociativity.Right;
break;
case TokenType.Modulo:
t.Precedence = 7;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.GreaterThan:
t.Precedence = 5;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.GreaterThanOrEqualTo:
t.Precedence = 5;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.LessThan:
t.Precedence = 5;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.LessThanOrEqualTo:
t.Precedence = 5;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.Equal:
t.Precedence = 4;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.NotEqual:
t.Precedence = 4;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.LogicalAnd:
t.Precedence = 3;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
case TokenType.LogicalOr:
t.Precedence = 2;
t.OperatorAssociativity = OperatorAssociativity.Left;
break;
default:
throw new ExpressionParserException(String.Format("Unknown operator{0}", t));
break;
}
return t;
}
