private Expression PredefinedAtom_IfNull(ParseTreeNode root, CompilerState state)
{
root.RequireChildren(2);
var arg1Node = root.RequireChild(null, 1, 0, 0);
var argument = state.ParentRuntime.Analyze(arg1Node, state);
var isnullableType = argument.IsNullableType();
var arg2Node = root.RequireChild(null, 1, 0, 1);
var ifnull = state.ParentRuntime.Analyze(arg2Node, state);
if (!ExpressionTreeExtensions.TryAdjustVoid(ref argument, ref ifnull))
{
throw new CompilationException("Could not adjust void blocks", root);
}
if (argument.IsVoid())
{
return(ifnull);
}
ifnull = ExpressionTreeExtensions.AdjustReturnType(arg2Node, ifnull, argument.Type.GetUnderlyingType());
Expression result;
if (argument.Type.IsValueType)
{
result = isnullableType
? Expression.Condition(Expression.Field(argument, "HasValue"), Expression.Field(argument, "Value"), ifnull)
: argument;
}
else
{
// now only reference types remaining
var constantExpression = argument as ConstantExpression;
if (constantExpression != null)
{
result = ReferenceEquals(constantExpression.Value, null) ? ifnull : argument;
}
else
{
result = Expression.Condition(Expression.Equal(argument, Expression.Constant(null)), ifnull, argument);
}
}
return(result.IsVoid() ? result : result.RemoveNullability());
}
private Expression BuildBinaryExpression(ParseTreeNode root, CompilerState state)
{
root.RequireChildren(3);
var leftNode = root.ChildNodes[0];
var leftExpr = Analyze(leftNode, state);
var op = GetBinaryOperator(root.ChildNodes[1]);
if (op == "in" || op == "not in")
{
return(BuildInclusionExpression(root, leftExpr, op, state));
}
var rightNode = root.ChildNodes[2];
var rightExpr = Analyze(rightNode, state);
if (!ExpressionTreeExtensions.TryAdjustVoid(ref leftExpr, ref rightExpr))
{
throw new CompilationException("This operation is not defined when both arguments are void", root);
}
Expression expr;
leftExpr = leftExpr.RemoveNullability();
rightExpr = rightExpr.RemoveNullability();
if (leftExpr.IsDateTime() && rightExpr.IsDateTime() ||
leftExpr.IsTimeSpan() && rightExpr.IsTimeSpan())
{
#region DateTime and DateTime, or TimeSpan and TimeSpan
switch (op)
{
case "+":
if (leftExpr.IsDateTime() && rightExpr.IsDateTime())
{
throw new CompilationException("Datetime values cannot be added to one another", root);
}
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Add);
break;
case "-":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Subtract);
break;
case "=":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Equal);
break;
case "!=":
case "<>":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.NotEqual);
break;
case ">":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.GreaterThan);
break;
case "<":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.LessThan);
break;
case "<=":
case "!>":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.LessThanOrEqual);
break;
case ">=":
case "!<":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.GreaterThanOrEqual);
break;
default:
throw new CompilationException("Binary operator not supported for datetime values: " + op, root.ChildNodes[1]);
}
#endregion
}
else if (leftExpr.IsDateTime() && rightExpr.IsTimeSpan())
{
#region DateTime and TimeSpan or TimeSpan and DateTime
switch (op)
{
case "+":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Add);
break;
case "-":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Subtract);
break;
default:
throw new CompilationException("Binary operator not supported for datetime and timespan: " + op, root.ChildNodes[1]);
}
#endregion
}
else if (leftExpr.IsTimeSpan() && rightExpr.IsDateTime())
{
#region TimeSpan and DateTime
switch (op)
{
case "+":
expr = ConstantHelper.TryEvalConst(root, rightExpr, leftExpr, ExpressionType.Add);
break;
default:
throw new CompilationException("Binary operator not supported for timespan and datetime: " + op, root.ChildNodes[1]);
}
#endregion
}
else if (leftExpr.IsString() && rightExpr.IsString())
{
#region String and String
switch (op)
{
case "+":
var concat = ReflectionHelper.StringConcat;
expr = ConstantHelper.TryEvalConst(root, concat, leftExpr, rightExpr);
break;
case "=":
case "!=":
case "<>":
expr = PrepareStringEquality(root, leftExpr, rightExpr);
if (op[0] != '=')
{
expr = ConstantHelper.TryEvalConst(root, expr, ExpressionType.Not, expr.Type);
}
break;
case ">":
expr = ConstantHelper.TryEvalConst(root, PrepareStringComparison(root, leftExpr, rightExpr), Expression.Constant(0), ExpressionType.GreaterThan);
break;
case "<":
expr = ConstantHelper.TryEvalConst(root, PrepareStringComparison(root, leftExpr, rightExpr), Expression.Constant(0), ExpressionType.LessThan);
break;
case "<=":
case "!>":
expr = ConstantHelper.TryEvalConst(root, PrepareStringComparison(root, leftExpr, rightExpr), Expression.Constant(0), ExpressionType.LessThanOrEqual);
break;
case ">=":
case "!<":
expr = ConstantHelper.TryEvalConst(root, PrepareStringComparison(root, leftExpr, rightExpr), Expression.Constant(0), ExpressionType.GreaterThanOrEqual);
break;
case "like":
throw new CompilationException("Instead of LIKE, use predefined functions StartsWith, EndsWith and Contains", root.ChildNodes[1]);
default:
throw new CompilationException("Binary operator not supported for strings: " + op, root.ChildNodes[1]);
}
#endregion
}
else if (leftExpr.IsNumeric() && rightExpr.IsNumeric())
{
#region Numeric and Numeric
ExpressionTreeExtensions.AdjustArgumentsForBinaryOperation(ref leftExpr, ref rightExpr, root);
switch (op)
{
case "+":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Add);
break;
case "-":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Subtract);
break;
case "*":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Multiply);
break;
case "/":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Divide);
break;
case "%":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Modulo);
break;
case "&":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.And);
break;
case "|":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Or);
break;
case "^":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.ExclusiveOr);
break;
case "<":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.LessThan);
break;
case "<=":
case "!>":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.LessThanOrEqual);
break;
case ">":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.GreaterThan);
break;
case ">=":
case "!<":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.GreaterThanOrEqual);
break;
case "=":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Equal);
break;
case "!=":
case "<>":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.NotEqual);
break;
default:
throw new CompilationException("Binary operator not supported yet for numerics: " + op, root.ChildNodes[1]);
}
#endregion
}
else if (leftExpr.IsBoolean() && rightExpr.IsBoolean())
{
#region Boolean and Boolean
switch (op)
{
case "and":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.AndAlso);
break;
case "or":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.OrElse);
break;
case "xor":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.ExclusiveOr);
break;
case "=":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.Equal);
break;
case "!=":
case "<>":
expr = ConstantHelper.TryEvalConst(root, leftExpr, rightExpr, ExpressionType.NotEqual);
break;
default:
throw new CompilationException("Binary operator not supported yet for booleans: " + op, root.ChildNodes[1]);
}
#endregion
}
else
{
throw new CompilationException(string.Format("Binary operator {0} is not yet supported for types {1} and {2}",
op, leftExpr.Type.FullName, rightExpr.Type.FullName), root.ChildNodes[1]);
}
return(expr);
}