public void ExitFactor(QueryParser.FactorContext context)
{
BaseValue constantValue = null;
// parse INT
var constantToken = context.INT();
if (constantToken != null)
{
var value = int.Parse(constantToken.Symbol.Text, CultureInfo.InvariantCulture);
constantValue = new IntValue(value);
}
else if (context.REAL() != null) // parse REAL
{
constantToken = context.REAL();
var value = double.Parse(constantToken.Symbol.Text, CultureInfo.InvariantCulture);
constantValue = new RealValue(value);
}
else if (context.STRING() != null) // parse STRING
{
constantToken = context.STRING();
constantValue = new StringValue(ParseStringValue(constantToken.Symbol));
}
// if this is a constant
if (constantValue != null)
{
_expressions.Push(new ConstantExpression(
constantToken.Symbol.Line,
constantToken.Symbol.Column,
constantValue));
return;
}
// parse ID
string identifier = null;
var identifierToken = context.ID();
if (identifierToken != null)
{
identifier = identifierToken.Symbol.Text;
}
else if (context.COMPLEX_ID() != null) // parse COMPLEX_ID
{
identifierToken = context.COMPLEX_ID();
identifier = ParseComplexIdentifier(identifierToken.Symbol);
}
// this is an ID or a function call
if (identifierToken != null)
{
if (context.LPAREN() == null) // attribute access
{
_expressions.Push(new AttributeAccessExpression(
identifierToken.Symbol.Line,
identifierToken.Symbol.Column,
identifier));
}
else // function call
{
var stackTop = _expressionsFrameStart.Pop();
var parameters = new List <ValueExpression>();
while (_expressions.Count > stackTop)
{
parameters.Add(_expressions.Pop());
}
parameters.Reverse();
_expressions.Push(new FunctionCallExpression(
identifierToken.Symbol.Line,
identifierToken.Symbol.Column,
identifier,
parameters));
}
return;
}
// if this is a unary minus
var unaryOperator = context.ADD_SUB();
if (unaryOperator != null)
{
if (unaryOperator.Symbol.Text == "-")
{
var parameter = _expressions.Pop();
_expressions.Push(new UnaryMinusExpression(
unaryOperator.Symbol.Line,
unaryOperator.Symbol.Column,
parameter));
}
}
// otherwise, this is a subexpression => it is already on the stack
}
/// <summary>
/// Exit a parse tree produced by <see cref="QueryParser.factor"/>.
/// <para>The default implementation does nothing.</para>
/// </summary>
/// <param name="context">The parse tree.</param>
public virtual void ExitFactor([NotNull] QueryParser.FactorContext context)
{
}
public void EnterFactor(QueryParser.FactorContext context)
{
}
