// Get the ExpressionType for an operator
private ExpressionType GetOpType(KeywordToken keyword)
{
if (keyword == KeywordToken.Add)
{
return(ExpressionType.Add);
}
if (keyword == KeywordToken.Substract)
{
return(ExpressionType.Subtract);
}
if (keyword == KeywordToken.Muliply)
{
return(ExpressionType.Multiply);
}
if (keyword == KeywordToken.Divide)
{
return(ExpressionType.Divide);
}
if (keyword == KeywordToken.Equal)
{
return(ExpressionType.Equal);
}
if (keyword == KeywordToken.NotEqual)
{
return(ExpressionType.NotEqual);
}
if (keyword == KeywordToken.GreaterThan)
{
return(ExpressionType.GreaterThan);
}
if (keyword == KeywordToken.LessThan)
{
return(ExpressionType.LessThan);
}
if (keyword == KeywordToken.And)
{
return(ExpressionType.And);
}
if (keyword == KeywordToken.Or)
{
return(ExpressionType.Or);
}
if (keyword == KeywordToken.Not)
{
return(ExpressionType.Not);
}
throw new SymplParseException(
"Unrecognized keyword for operators");
}
// This parses a BinaryOp expression.
//
private SymplBinaryExpr ParseExprTreeBinaryOp(Lexer lexr)
{
KeywordToken keyword = lexr.GetToken() as KeywordToken;
if (keyword == null)
{
throw new SymplParseException(
"Internal error: parsing Binary?");
}
SymplExpr left, right;
ParseBinaryRuntimeCall(lexr, out left, out right);
var op = GetOpType(keyword);
return(new SymplBinaryExpr(left, right, op));
}
// Keep whatever casing we found in the source program so that when the
// IDs are used a member names and metadata on binders, then if some MO
// doesn't respect the IgnoreCase flag, there's an out for still binding.
//
private IdOrKeywordToken MakeIdOrKeywordToken(string name, bool quotedId)
{
if (!quotedId && KeywordToken.IsKeywordName(name))
{
return(KeywordToken.GetKeywordToken(name));
}
else
{
if (name.ToLower() == "let")
{
System.Console.WriteLine();
System.Console.WriteLine(
"WARNING: using 'let'? You probably meant let*.");
System.Console.WriteLine();
}
return(new IdOrKeywordToken(name));
}
}
// This parses a UnaryOp expression.
//
private SymplUnaryExpr ParseExprTreeUnaryOp(Lexer lexr)
{
KeywordToken keyword = lexr.GetToken() as KeywordToken;
if (keyword == null)
{
throw new SymplParseException(
"Internal error: parsing Unary?");
}
var op = GetOpType(keyword);
var operand = ParseExprAux(lexr);
if (lexr.GetToken() != SyntaxToken.CloseParen)
{
throw new SymplParseException(
"Unary expression missing close paren.");
}
return(new SymplUnaryExpr(operand, op));
}