protected override Expression VisitBinary(BinaryExpression node)
{
Visit(node.Left);
var left = _expression;
Visit(node.Right);
var right = _expression;
Operator @operator;
switch (node.NodeType)
{
case ExpressionType.And:
case ExpressionType.AndAlso:
@operator = Operator.And;
break;
case ExpressionType.Or:
case ExpressionType.OrElse:
@operator = Operator.Or;
break;
case ExpressionType.ExclusiveOr:
@operator = Operator.OperatorXor;
break;
default:
throw new NotSupportedException(node.ToString());
}
_expression = new OperatorExpression(@operator) { Branches = new[]{left,right}};
return node;
}
protected List<Microsoft.Z3.BoolExpr> VisitBinary(BinaryExpression b)
{
// Use recursion to generate Z3 constraints for each operand of the binary expression
// left side -> create a Z3 expression representing the left side
Expression left = Visit(b.Left);
// right side -> creat a Z3 expression representing the right side
Expression right = Visit(b.Right);
// Put those into a Z3 format
ExpressionType op = b.NodeType;
using (Context ctx = new Context())
{
if (op == ExpressionType.LessThan)
{
// ctx.MkLt(left, right);
}
}
Console.WriteLine(b.ToString());
// TODO - return a Z3 expression
return null;
}
public void CloseContext(BinaryExpression node)
{
if(!_contexts.Any()) return;
var last = _contexts.Last();
if (last.ContextKey == node.ToString()) {
_contexts.Remove(last);
}
}
public static void Main()
{
// Numeric comparison
var user1 = new User {
Age = 13, Name = "Adam"
};
var user2 = new User {
Age = 33, Name = "John"
};
var user3 = new User {
Age = 53, Name = "DBag"
};
// Equal, NotEqual, GreaterThanOrEqual, GreaterThan, LessThan, LessThanOrEqual
var rule = new Rule("Age", "LessThanOrEqual", "33");
Func <User, bool> compiledRule = CompileUserRule <User>(rule);
Console.WriteLine("Rule: " + rule.MemberName + " " + rule.Operator + " " + rule.TargetValue);
Console.WriteLine("Evaluating Rule:");
Console.WriteLine("\tuser1: Name: " + user1.Name + ", Age: " + user1.Age + " : " + compiledRule(user1));
Console.WriteLine("\tuser2: Name: " + user2.Name + ", Age: " + user2.Age + " : " + compiledRule(user2));
Console.WriteLine("\tuser3: Name: " + user3.Name + ", Age: " + user3.Age + " : " + compiledRule(user3));
// Search within a string
var mystring = new simpleString {
searchValue = "I got ants!"
};
rule = new Rule("searchValue", "Contains", "ants");
Func <simpleString, bool> compiledStringRule = CompileStringRule <simpleString>(rule);
compiledStringRule = CompileStringRule <simpleString>(rule);
Console.WriteLine("\nRule: " + rule.MemberName + " " + rule.Operator + " " + rule.TargetValue);
Console.WriteLine("Evaluating Rule:");
Console.WriteLine("\tsearchValue: \"" + mystring.searchValue + "\" : " + compiledStringRule(mystring));
mystring.searchValue = "If you see something, say something.";
Console.WriteLine("\tsearchValue: \"" + mystring.searchValue + "\" : " + compiledStringRule(mystring));
// Dynamic rule creation and execution
Console.WriteLine("\nDynamically constructed rule with simple math expression:");
System.Linq.Expressions.BinaryExpression binaryExpression =
System.Linq.Expressions.Expression.MakeBinary(
System.Linq.Expressions.ExpressionType.Divide,
System.Linq.Expressions.Expression.Constant(1000),
System.Linq.Expressions.Expression.Constant(20)
);
Console.WriteLine("\tRule: " + binaryExpression.ToString());
// Compile the expression.
var compiledExpression = Expression.Lambda <Func <int> >(binaryExpression).Compile();
// Execute the expression.
Console.WriteLine("\tResult of rule execution: " + compiledExpression());
Console.WriteLine("\nHit any key to exit");
Console.ReadKey();
}
public void OpenContext(ConvertedExpression expression, BinaryExpression node)
{
if (!SupportedMethods.Contains((expression.Equality ?? string.Empty).TrimStart(ExpressionType.Not.ToString().ToCharArray())))
return;
_contexts.Add(new SubQueryContext { Target = expression.Target,
ContextKey = node.ToString(),
// ReSharper disable PossibleNullReferenceException
NegateContext = expression.Equality.StartsWith(ExpressionType.Not.ToString())
// ReSharper restore PossibleNullReferenceException
});
}
internal override Expression VisitBinary(BinaryExpression b)
{
if (ClientType.CheckElementTypeIsEntity(b.Left.Type) || ClientType.CheckElementTypeIsEntity(b.Right.Type)
|| IsCollectionProducingExpression(b.Left) || IsCollectionProducingExpression(b.Right))
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjection(this.type, b.ToString()));
}
return base.VisitBinary(b);
}
internal override Expression VisitBinary(BinaryExpression b)
{
throw new NotSupportedException(Strings.ALinq_ExpressionNotSupportedInProjectionToEntity(this.type, b.ToString()));
}
protected override Expression VisitBinary(BinaryExpression b)
{
if (b.NodeType == ExpressionType.Coalesce)
{
sb.Append("IsNull(");
Visit(b.Left);
sb.Append(",");
Visit(b.Right);
sb.Append(")");
}
else if (b.NodeType == ExpressionType.Equal || b.NodeType == ExpressionType.NotEqual)
{
if (b.Left is ConstantExpression)
{
if (b.Right is ConstantExpression)
throw new NotSupportedException("NULL == NULL not supported");
Field field = GetField(b.Right);
sb.Append(Equals(field, ((ConstantExpression)b.Left).Value, b.NodeType == ExpressionType.Equal));
}
else if (b.Right is ConstantExpression)
{
Field field = GetField(b.Left);
sb.Append(Equals(field, ((ConstantExpression)b.Right).Value, b.NodeType == ExpressionType.Equal));
}
else
throw new NotSupportedException("Impossible to translate {0}".FormatWith(b.ToString()));
}
else
{
sb.Append("(");
this.Visit(b.Left);
switch (b.NodeType)
{
case ExpressionType.And:
case ExpressionType.AndAlso:
sb.Append(b.Type.UnNullify() == typeof(bool) ? " AND " : " & ");
break;
case ExpressionType.Or:
case ExpressionType.OrElse:
sb.Append(b.Type.UnNullify() == typeof(bool) ? " OR " : " | ");
break;
case ExpressionType.ExclusiveOr:
sb.Append(" ^ ");
break;
case ExpressionType.LessThan:
sb.Append(" < ");
break;
case ExpressionType.LessThanOrEqual:
sb.Append(" <= ");
break;
case ExpressionType.GreaterThan:
sb.Append(" > ");
break;
case ExpressionType.GreaterThanOrEqual:
sb.Append(" >= ");
break;
case ExpressionType.Add:
case ExpressionType.AddChecked:
sb.Append(" + ");
break;
case ExpressionType.Subtract:
case ExpressionType.SubtractChecked:
sb.Append(" - ");
break;
case ExpressionType.Multiply:
case ExpressionType.MultiplyChecked:
sb.Append(" * ");
break;
case ExpressionType.Divide:
sb.Append(" / ");
break;
case ExpressionType.Modulo:
sb.Append(" % ");
break;
default:
throw new NotSupportedException(string.Format("The binary operator {0} is not supported", b.NodeType));
}
this.Visit(b.Right);
sb.Append(")");
}
return b;
}
internal override Expression VisitBinary(BinaryExpression b)
{
if (CommonUtil.IsClientType(b.Left.Type) || CommonUtil.IsClientType(b.Right.Type))
{
throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, SR.ALinqExpressionNotSupportedInProjection, this.type, b.ToString()));
}
return base.VisitBinary(b);
}
internal override Expression VisitBinary(BinaryExpression b)
{
throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, SR.ALinqExpressionNotSupportedInProjectionToEntity, this.type, b.ToString()));
}
private string TranslateBinary(BinaryExpression expression)
{
if (expression.Right.NodeType == ExpressionType.Constant && (((ConstantExpression)expression.Right).Value == null))
{
switch (expression.NodeType)
{
case ExpressionType.Equal:
return "(" + Translate(expression.Left) + " IS NULL)";
case ExpressionType.NotEqual:
return "(" + Translate(expression.Left) + " IS NOT NULL)";
default:
throw new SqlExpressionTranslatorException(expression.ToString());
}
}
string op;
switch (expression.NodeType)
{
case ExpressionType.Add:
case ExpressionType.AddChecked:
op = "+";
break;
case ExpressionType.AndAlso:
op = "AND";
break;
case ExpressionType.Coalesce:
{
string sql = _sqlDialect.SqlFunction(SqlDialect.Function.Coalesce, Translate(expression.Left), Translate(expression.Right));
return expression.Type == typeof (bool) ? TranslateTrue(sql) : sql;
}
case ExpressionType.Divide:
op = "/";
break;
case ExpressionType.Equal:
op = "=";
break;
case ExpressionType.GreaterThan:
op = ">";
break;
case ExpressionType.GreaterThanOrEqual:
op = ">=";
break;
case ExpressionType.LessThan:
op = "<";
break;
case ExpressionType.LessThanOrEqual:
op = "<=";
break;
case ExpressionType.Multiply:
case ExpressionType.MultiplyChecked:
op = "*";
break;
case ExpressionType.NotEqual:
op = "<>";
break;
case ExpressionType.OrElse:
op = "OR";
break;
case ExpressionType.Subtract:
case ExpressionType.SubtractChecked:
op = "-";
break;
default:
throw new SqlExpressionTranslatorException(expression.ToString());
}
return $"({Translate(expression.Left)} {op} {Translate(expression.Right)})";
}
//
// Listing 12-36
//
/// <summary>
/// Performs a sanity check of constant and memberAccess
/// Then it performs a different translation according to
/// the type of the member to be compared with
/// </summary>
private Expression VisitBinaryComparison(BinaryExpression b)
{
// FIRST STEP
// We support only a comparison between constant
// and a possible Images query parameter
ConstantExpression constant =
(b.Left as ConstantExpression ?? b.Right as ConstantExpression);
MemberExpression memberAccess =
(b.Left as MemberExpression ?? b.Right as MemberExpression);
// SECOND STEP
// Sanity check of parameters
if ((memberAccess == null) || (constant == null))
{
throw new NotSupportedException(
string.Format(
"The binary operator '{0}' must compare a valid Images attribute with a constant",
b.NodeType));
}
// We need to get the constant value
if (constant.Value == null)
{
throw new NotSupportedException(
string.Format(
"NULL constant is not supported in binary operator {0}",
b.ToString()));
}
switch (Type.GetTypeCode(constant.Value.GetType()))
{
case TypeCode.String:
case TypeCode.Int16:
case TypeCode.Int32:
case TypeCode.Double:
break;
default:
throw new NotSupportedException(
string.Format(
"Constant {0} is of an unsupported type ({1})",
constant.ToString(),
constant.Value.GetType().Name));
}
// THIRD STEP
// Look for member name through Reflection
// We assume that string properties in Images have the same name
// in QueryParameters
// We have a special check for Images members of complex types
if (memberAccess.Member.ReflectedType == typeof(DateTime))
{
TranslateTimeSpanComparison(b.NodeType, constant, memberAccess);
return b;
}
else if (memberAccess.Member.ReflectedType == typeof(CameraInformation))
{
TranslateCameraInformationComparison(constant, memberAccess);
return b;
}
else if (memberAccess.Member.ReflectedType != typeof(ImageInformation))
{
throw new NotSupportedException(
string.Format(
"Member {0} is not of type Images",
memberAccess.ToString()));
}
TranslateStandardComparisons(b.NodeType, constant, memberAccess);
return b;
}
/// <summary>
/// Process binary comparison operators.
/// </summary>
/// <param name="expression">
/// The expression to visit.
/// </param>
/// <returns>
/// The visited expression.
/// </returns>
private Expression VisitBinary(BinaryExpression expression)
{
if (expression != null)
{
// special case for enums, because we send them as strings
UnaryExpression enumExpression = null;
ConstantExpression constantExpression = null;
BinaryExpression stringCompareExpression = null;
if (this.CheckEnumExpression(expression, out enumExpression, out constantExpression))
{
this.Visit(this.RewriteEnumExpression(enumExpression, (ConstantExpression)expression.Right, expression.NodeType));
}
// special case concat as it's OData function isn't infix
else if (expression.NodeType == ExpressionType.Add &&
expression.Left.Type == typeof(string) &&
expression.Right.Type == typeof(string))
{
//rewrite addition into a call to concat, instead of duplicating generation code.
this.Visit(this.RewriteStringAddition(expression));
}
// special case for string comparisons emitted by the VB compiler
else if (this.CheckVBStringCompareExpression(expression, out stringCompareExpression))
{
this.Visit(stringCompareExpression);
}
else
{
BinaryOperatorKind operatorKind;
switch (expression.NodeType)
{
case ExpressionType.AndAlso:
case ExpressionType.And:
operatorKind = BinaryOperatorKind.And;
break;
case ExpressionType.Or:
case ExpressionType.OrElse:
operatorKind = BinaryOperatorKind.Or;
break;
case ExpressionType.Equal:
operatorKind = BinaryOperatorKind.Equal;
break;
case ExpressionType.NotEqual:
operatorKind = BinaryOperatorKind.NotEqual;
break;
case ExpressionType.LessThan:
operatorKind = BinaryOperatorKind.LessThan;
break;
case ExpressionType.LessThanOrEqual:
operatorKind = BinaryOperatorKind.LessThanOrEqual;
break;
case ExpressionType.GreaterThan:
operatorKind = BinaryOperatorKind.GreaterThan;
break;
case ExpressionType.GreaterThanOrEqual:
operatorKind = BinaryOperatorKind.GreaterThanOrEqual;
break;
case ExpressionType.Add:
operatorKind = BinaryOperatorKind.Add;
break;
case ExpressionType.Subtract:
operatorKind = BinaryOperatorKind.Subtract;
break;
case ExpressionType.Multiply:
operatorKind = BinaryOperatorKind.Multiply;
break;
case ExpressionType.Divide:
operatorKind = BinaryOperatorKind.Divide;
break;
case ExpressionType.Modulo:
operatorKind = BinaryOperatorKind.Modulo;
break;
default:
throw new NotSupportedException(
string.Format(
CultureInfo.InvariantCulture,
"The operator '{0}' is not supported in the 'Where' Mobile Services query expression '{1}'.",
expression.NodeType,
expression.ToString()));
}
var node = new BinaryOperatorNode(operatorKind, null, null);
this.filterExpression.Push(node);
this.Visit(expression.Left);
this.Visit(expression.Right);
this.SetChildren(node);
}
}
return expression;
}
/// <summary>
/// Deal with a special case for an index redirection where we are looking for
/// an integer or some simply type. There is only one very special case where this
/// shows up. Unlikely to be used by physics, actually. :-) The second case we
/// handle is dealing with != for two object compares.
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
protected override Expression VisitBinary(BinaryExpression expression)
{
//
// If we are comparing a "new" against a null, then we don't support that.
//
if (expression.Left.IsNull() || expression.Right.IsNull())
{
Expression nonNull = expression.Left.IsNull() ? expression.Right : expression.Left;
if (nonNull.NodeType == ExpressionType.New)
{
throw new InvalidOperationException(string.Format("Doing a null comparison to a temporary object created in the query is very likely to generate incorrect code - not supported ({0})", expression.ToString()));
}
}
// If this is an array index, then...
if (expression.NodeType == ExpressionType.ArrayIndex && expression.IsLeafType())
{
var rootExpr = expression.Left as MemberExpression;
if (rootExpr != null)
{
return Expression.ArrayIndex(VisitExpressionImplemented(rootExpr), expression.Right);
}
}
// If this is a comparison, and these are objects that have indicies (in whatever we are looping through)...
if (expression.NodeType == ExpressionType.Equal || expression.NodeType == ExpressionType.NotEqual)
{
// Are we pointing to something we can deal with?
var indexLeft = ExtractIndexReference(expression.Left);
if (indexLeft != null)
{
var indexRight = ExtractIndexReference(expression.Right);
if (indexRight != null)
{
if (expression.NodeType == ExpressionType.NotEqual)
{
return Expression.NotEqual(indexLeft, indexRight);
} else
{
return Expression.Equal(indexLeft, indexRight);
}
}
}
}
return base.VisitBinary(expression);
}
internal override Expression VisitBinary(BinaryExpression b)
{
if ((ClientTypeUtil.TypeOrElementTypeIsEntity(b.Left.Type) || ClientTypeUtil.TypeOrElementTypeIsEntity(b.Right.Type)) || (ProjectionAnalyzer.IsCollectionProducingExpression(b.Left) || ProjectionAnalyzer.IsCollectionProducingExpression(b.Right)))
{
throw new NotSupportedException(System.Data.Services.Client.Strings.ALinq_ExpressionNotSupportedInProjection(this.type, b.ToString()));
}
return base.VisitBinary(b);
}
/// <summary>
/// Process binary comparison operators.
/// </summary>
/// <param name="expression">
/// The expression to visit.
/// </param>
/// <returns>
/// The visited expression.
/// </returns>
private Expression VisitBinary(BinaryExpression expression)
{
if (expression != null)
{
// special case for enums, because we send them as strings
UnaryExpression enumExpression = null;
ConstantExpression constantExpression = null;
if (this.CheckEnumExpression(expression, out enumExpression, out constantExpression))
{
this.Visit(this.RewriteEnumExpression(enumExpression, (ConstantExpression)expression.Right, expression.NodeType));
}
// special case concat as it's OData function isn't infix
else if (expression.NodeType == ExpressionType.Add &&
expression.Left.Type == typeof(string) &&
expression.Right.Type == typeof(string))
{
//rewrite addition into a call to concat, instead of duplicating generation code.
this.Visit(this.RewriteStringAddition(expression));
}
else
{
this.filter.Append("(");
this.Visit(expression.Left);
switch (expression.NodeType)
{
case ExpressionType.AndAlso:
this.filter.Append(" and ");
break;
case ExpressionType.OrElse:
this.filter.Append(" or ");
break;
case ExpressionType.Equal:
this.filter.Append(" eq ");
break;
case ExpressionType.NotEqual:
this.filter.Append(" ne ");
break;
case ExpressionType.LessThan:
this.filter.Append(" lt ");
break;
case ExpressionType.LessThanOrEqual:
this.filter.Append(" le ");
break;
case ExpressionType.GreaterThan:
this.filter.Append(" gt ");
break;
case ExpressionType.GreaterThanOrEqual:
this.filter.Append(" ge ");
break;
case ExpressionType.Add:
this.filter.Append(" add ");
break;
case ExpressionType.Subtract:
this.filter.Append(" sub ");
break;
case ExpressionType.Multiply:
this.filter.Append(" mul ");
break;
case ExpressionType.Divide:
this.filter.Append(" div ");
break;
case ExpressionType.Modulo:
this.filter.Append(" mod ");
break;
default:
throw new NotSupportedException(
string.Format(
CultureInfo.InvariantCulture,
Resources.FilterBuildingExpressionVisitor_OperatorUnsupported,
expression.NodeType,
expression.ToString()));
}
this.Visit(expression.Right);
this.filter.Append(")");
}
}
return expression;
}
private static CriteriaOperator ProcessBinaryExpression(BinaryExpression expression, ParameterOption option)
{
switch (expression.NodeType)
{
case ExpressionType.AndAlso:
return ProcessAndExpression(expression, option);
case ExpressionType.OrElse:
return ProcessOrExpression(expression, option);
case ExpressionType.Equal:
case ExpressionType.NotEqual:
case ExpressionType.GreaterThan:
case ExpressionType.GreaterThanOrEqual:
case ExpressionType.LessThan:
case ExpressionType.LessThanOrEqual:
if (IsMemberExpression(expression.Right))
return ProcessMemberExpression(expression, option);
else
return ProcessSimpleExpression(expression, option);
default:
throw new Exception("Unhandled binary expression: " + expression.NodeType + ", " + expression.ToString());
}
}
/// <summary>
/// Process binary comparison operators.
/// </summary>
/// <param name="expression">The expression to visit.</param>
/// <returns>The visited expression.</returns>
protected override Expression VisitBinary(BinaryExpression expression)
{
if (expression != null)
{
// Special case concat as it's OData function isn't infix
if (expression.NodeType == ExpressionType.Add &&
expression.Left.Type == typeof(string) &&
expression.Right.Type == typeof(string))
{
this.filter.Append("concat(");
this.Visit(expression.Left);
this.filter.Append(",");
this.Visit(expression.Right);
this.filter.Append(")");
}
else
{
this.filter.Append("(");
this.Visit(expression.Left);
switch (expression.NodeType)
{
case ExpressionType.AndAlso:
this.filter.Append(" and ");
break;
case ExpressionType.OrElse:
this.filter.Append(" or ");
break;
case ExpressionType.Equal:
this.filter.Append(" eq ");
break;
case ExpressionType.NotEqual:
this.filter.Append(" ne ");
break;
case ExpressionType.LessThan:
this.filter.Append(" lt ");
break;
case ExpressionType.LessThanOrEqual:
this.filter.Append(" le ");
break;
case ExpressionType.GreaterThan:
this.filter.Append(" gt ");
break;
case ExpressionType.GreaterThanOrEqual:
this.filter.Append(" ge ");
break;
case ExpressionType.Add:
this.filter.Append(" add ");
break;
case ExpressionType.Subtract:
this.filter.Append(" sub ");
break;
case ExpressionType.Multiply:
this.filter.Append(" mul ");
break;
case ExpressionType.Divide:
this.filter.Append(" div ");
break;
case ExpressionType.Modulo:
this.filter.Append(" mod ");
break;
default:
throw new NotSupportedException(
string.Format(
CultureInfo.InvariantCulture,
Resources.FilterBuildingExpressionVisitor_VisitOperator_Unsupported,
expression.NodeType,
expression.ToString()));
}
this.Visit(expression.Right);
this.filter.Append(")");
}
this.MarkVisited();
}
return expression;
}
private static string ExtractOperator(BinaryExpression binary)
{
string op = Regex.Match(binary.ToString(), " (==|=|!=|<=|>=|<|>) ").Groups[1].Value;
if (op == "==" ||op =="=")
return "should equal";
if (op == "!=")
return "should not equal";
if (op == "<=")
return "should be less than or equal to";
if (op == "<")
return "should be less than";
if (op == ">=")
return "should be greater than or equal to";
if (op == ">")
return "should be greater than";
return "should " + op;
}
