public override ExpressionResult VisitBinary(EntityGraphQLParser.BinaryContext context)
{
var left = Visit(context.left);
var right = Visit(context.right);
var op = MakeOperator(context.op.GetText());
// we may need to do some converting here
if (left.Type != right.Type)
{
if (op == ExpressionType.Equal || op == ExpressionType.NotEqual)
{
var result = DoObjectComparisonOnDifferentTypes(op, left, right);
if (result != null)
{
return(result);
}
}
return(ConvertLeftOrRight(op, left, right));
}
if (op == ExpressionType.Add && left.Type == typeof(string) && right.Type == typeof(string))
{
return((ExpressionResult)Expression.Call(null, typeof(string).GetMethod("Concat", new[] { typeof(string), typeof(string) }), left, right));
}
return((ExpressionResult)Expression.MakeBinary(op, left, right));
}
public override ExpressionResult VisitBinary(EntityGraphQLParser.BinaryContext context)
{
var left = Visit(context.left);
var right = Visit(context.right);
var op = MakeOperator(context.op.GetText());
// we may need to do some converting here
if (left.Type != right.Type)
{
if (op == ExpressionType.Equal || op == ExpressionType.NotEqual)
{
var result = DoObjectComparisonOnDifferentTypes(op, left, right);
if (result != null)
{
return(result);
}
}
return(ConvertLeftOrRight(op, left, right));
}
if (left.Type == typeof(string) && right.Type == typeof(string))
{
if (op == ExpressionType.Add)
{
return((ExpressionResult)Expression.Call(null, typeof(string).GetMethod("Concat", new[] { typeof(string), typeof(string) }), left, right));
}
if (op == ExpressionType.GreaterThan || op == ExpressionType.GreaterThanOrEqual || op == ExpressionType.LessThan || op == ExpressionType.LessThanOrEqual)
{
MethodInfo methodInfo = typeof(string).GetMethod("CompareTo", new[] { typeof(string) });
var callExpr = Expression.Call(left, methodInfo, right);
ExpressionResult searchExpr = null;
if (op == ExpressionType.GreaterThan)
{
searchExpr = (ExpressionResult)Expression.GreaterThan(callExpr, Expression.Constant(0));
}
if (op == ExpressionType.GreaterThanOrEqual)
{
searchExpr = (ExpressionResult)Expression.GreaterThanOrEqual(callExpr, Expression.Constant(0));
}
if (op == ExpressionType.LessThan)
{
searchExpr = (ExpressionResult)Expression.LessThan(callExpr, Expression.Constant(0));
}
if (op == ExpressionType.LessThanOrEqual)
{
searchExpr = (ExpressionResult)Expression.LessThanOrEqual(callExpr, Expression.Constant(0));
}
return(searchExpr);
}
}
return((ExpressionResult)Expression.MakeBinary(op, left, right));
}
