/// <summary>
/// Gets the return type of the expression when evaluated.
/// </summary>
/// <param name="expression">The expression to check.</param>
/// <param name="query">The query context used to evaluate the return type
/// of the expression.</param>
/// <param name="variableResolver">The object used to resolve variable references in the expression tree.</param>
/// <returns>
/// Returns the <see cref="SqlType"/> that an evaluation of the expression
/// would return, or <c>null</c> if the final result of the evaluation has
/// no return type.
/// </returns>
public static SqlType ReturnType(this SqlExpression expression, IRequest query, IVariableResolver variableResolver)
{
var visitor = new ReturnTypeVisitor(query, variableResolver);
return visitor.GetType(expression);
}
/// <summary>
/// Gets the return type of the expression when evaluated.
/// </summary>
/// <param name="expression">The expression to check.</param>
/// <param name="query">The query context used to evaluate the return type
/// of the expression.</param>
/// <param name="variableResolver">The object used to resolve variable references in the expression tree.</param>
/// <returns>
/// Returns the <see cref="SqlType"/> that an evaluation of the expression
/// would return, or <c>null</c> if the final result of the evaluation has
/// no return type.
/// </returns>
public static SqlType ReturnType(this SqlExpression expression, IRequest query, IVariableResolver variableResolver)
{
var visitor = new ReturnTypeVisitor(query, variableResolver);
return(visitor.GetType(expression));
}
/// <summary>
/// Gets the return type of the expression when evaluated.
/// </summary>
/// <param name="expression">The expression to check.</param>
/// <param name="queryContext">The query context used to evaluate the return type
/// of the expression.</param>
/// <param name="variableResolver">The object used to resolve variable references in the expression tree.</param>
/// <returns>
/// Returns the <see cref="DataType"/> that an evaluation of the expression
/// would return, or <c>null</c> if the final result of the evaluation has
/// no return type.
/// </returns>
public static DataType ReturnType(this SqlExpression expression, IQueryContext queryContext, IVariableResolver variableResolver)
{
var visitor = new ReturnTypeVisitor(queryContext, variableResolver);
return visitor.GetType(expression);
}
