public void ExitComparison(QueryParser.ComparisonContext context)
{
var opToken = context.REL_OP();
if (opToken == null)
{
return;
}
var op = opToken.Symbol;
var right = _expressions.Pop();
var left = _expressions.Pop();
BinaryOperatorExpression value = null;
switch (op.Text)
{
case "<":
value = new LessThanOperator(op.Line, op.Column, left, right);
break;
case "<=":
value = new LessThanOrEqualOperator(op.Line, op.Column, left, right);
break;
case "<>":
case "!=":
value = new NotEqualOperator(op.Line, op.Column, left, right);
break;
case "==":
case "=":
value = new EqualOperator(op.Line, op.Column, left, right);
break;
case ">":
value = new GreaterThanOperator(op.Line, op.Column, left, right);
break;
case ">=":
value = new GreaterThanOrEqualOperator(op.Line, op.Column, left, right);
break;
}
Trace.Assert(value != null, "Invalid comparison operator " + op.Text);
_expressions.Push(value);
}
public void CreateExpressionTest1()
{
// Arrange
Expression parameterExpression = Expression.Parameter(typeof(Employee), "sample");
Expression expressionProperty = Expression.Property(parameterExpression, nameof(Employee.Age));
Expression expressionConstant = Expression.Constant(20);
Expression expectedExpression = Expression.GreaterThanOrEqual(expressionProperty, expressionConstant);
var _operator = new GreaterThanOrEqualOperator();
// Act
Expression resultExpression = _operator.CreateExpression(expressionProperty, expressionConstant);
// Assert
Assert.AreEqual(expectedExpression.ToString(), resultExpression.ToString(), "Expression not correct");
}
private static ExpTreeNode GetAsExpressionTree(this ParseTreeNode parsedNode, ExpTreeNode parentExpNode)
{
//The current node is a variable / value token. Create a value node and return it back
if (!parsedNode.ChildNodes.Any())
{
switch (parsedNode.Term.Name)
{
case "variable":
{
var varName = parsedNode.FindTokenAndGetValue <string>();
return(new VariableValue(varName, parentExpNode));
}
case "boolean":
return(new LiteralValue(parsedNode.FindTokenAndGetValue <bool>(), parentExpNode));
case "integer":
case "decimal":
return(new LiteralValue(parsedNode.FindTokenAndGetValue <double>(), parentExpNode));
case "SingleQuoteString":
case "DoubleQuoteString":
return(new LiteralValue(parsedNode.FindTokenAndGetValue <string>(), parentExpNode));
default:
throw parsedNode.GetException($"Invalid token type '{parsedNode.Term.Name}' in expression");
}
}
// Look on the next node down
else if (parsedNode.ChildNodes.Count == 1)
{
return(GetAsExpressionTree(parsedNode.ChildNodes[0], parentExpNode));
}
//Ignore parenthesis, the middle non-terminal is what we want
// Look on the next node down
else if (parsedNode.ChildNodes.Count == 3 && parsedNode.ChildNodes[0]?.Token?.Text == "(")
{
return(GetAsExpressionTree(parsedNode.ChildNodes[1], parentExpNode));
}
//Binary operator
else if (parsedNode.ChildNodes.Count == 3)
{
BinaryOperatorBase binaryOp;
var opStr = parsedNode.ChildNodes[1].FindToken().ValueString;
switch (opStr)
{
// Math
case "+":
binaryOp = new AdditionOperator(parentExpNode);
break;
case "-":
binaryOp = new SubtractionOperator(parentExpNode);
break;
case "*":
binaryOp = new MultiplacationOperator(parentExpNode);
break;
case "/":
binaryOp = new DivisionOperator(parentExpNode);
break;
case "%":
binaryOp = new ModulusOperator(parentExpNode);
break;
case "^":
binaryOp = new PowerOperator(parentExpNode);
break;
// Bool
case "~==":
binaryOp = new LooseEqualsOperator(parentExpNode);
break;
case "~!=":
binaryOp = new LooseNotEqualsOperator(parentExpNode);
break;
case "==":
binaryOp = new EqualsOperator(parentExpNode);
break;
case "!=":
binaryOp = new NotEqualsOperator(parentExpNode);
break;
case "like":
binaryOp = new LikeOperator(parentExpNode);
break;
case "match":
binaryOp = new MatchOperator(parentExpNode);
break;
case ">":
binaryOp = new GreaterThanOperator(parentExpNode);
break;
case ">=":
binaryOp = new GreaterThanOrEqualOperator(parentExpNode);
break;
case "<":
binaryOp = new LessThanOperator(parentExpNode);
break;
case "<=":
binaryOp = new LessThanOrEqualOperator(parentExpNode);
break;
case "&&":
binaryOp = new AndOperator(parentExpNode);
break;
case "||":
binaryOp = new OrOperator(parentExpNode);
break;
default:
throw parsedNode.ChildNodes[1].GetException($"Unrecognized operator '{opStr}'");
}
binaryOp.LeftOperand = GetAsExpressionTree(parsedNode.ChildNodes[0], binaryOp);
binaryOp.RightOperand = GetAsExpressionTree(parsedNode.ChildNodes[2], binaryOp);
//Optimize
if (binaryOp.LeftOperand is LiteralValue && binaryOp.RightOperand is LiteralValue)
{
return(new LiteralValue(binaryOp.Eval(), parentExpNode));
}
return(binaryOp);
}
// Unary operator
else if (parsedNode.ChildNodes.Count == 2)
{
var opVal = parsedNode.ChildNodes[0].FindToken().Value;
UnaryOperatorBase unaryOp;
if (parsedNode.ChildNodes[0].FindToken().Value is TypeCode convertType)
{
unaryOp = new TypeConversionOperator(convertType, parentExpNode);
}
else
{
var opStr = opVal.ToString();
switch (opStr)
{
case "!":
unaryOp = new NotOperator(parentExpNode);
break;
//Property Checking
case "lengthof":
unaryOp = new LengthOperator(parentExpNode);
break;
case "typeof":
unaryOp = new TypeOperator(parentExpNode);
break;
default:
unaryOp = new GenericUnaryMathFunctionOperator(opStr, parentExpNode);
break;
}
}
unaryOp.Operand = GetAsExpressionTree(parsedNode.ChildNodes[1], unaryOp);
//Optimize
if (unaryOp.Operand is LiteralValue)
{
return(new LiteralValue(unaryOp.Eval(), parentExpNode));
}
return(unaryOp);
}
else
{
throw parsedNode.GetException($"Invalid number of tokens ({parsedNode.ChildNodes.Count})");
}
}
public Bitmap Visit(GreaterThanOrEqualOperator expr)
{
return(ComputeFunction(expr));
}
public virtual void Visit(GreaterThanOrEqualOperator binaryOperator)
{
Visit(binaryOperator.Left);
Visit(binaryOperator.Right);
}
public override void Visit(GreaterThanOrEqualOperator binaryOperator)
{
WriteBinaryExpression(binaryOperator, ">=");
}
public override void Visit(GreaterThanOrEqualOperator binaryOperator)
{
Visit(binaryOperator.Left);
Write(" >= ");
Visit(binaryOperator.Right);
}