private ConstructedValueExpression MapTupleParameters(MapTypeContext context, MethodInfo factoryMethod, Type[] typeParams)
{
var expressions = new List <Expression>();
var variables = new List <ParameterExpression>();
var args = new Expression[typeParams.Length];
// We need to assign a value to every parameter. Loop over each parameter and map values where
// available. When we run out of columns or have a column we cannot map, fill in a default value.
// Where a value type may consume many columns (a custom object type, for example) it will
// greedily consume as much as possible before moving to the next parameter.
for (var i = 0; i < typeParams.Length; i++)
{
if (!context.HasColumns())
{
args[i] = typeParams[i].GetDefaultValueExpression();
continue;
}
var elementState = context.ChangeTargetType(typeParams[i]);
var expr = _values.Compile(elementState);
if (expr.IsNothing)
{
args[i] = typeParams[i].GetDefaultValueExpression();
continue;
}
expressions.AddRange(expr.Expressions);
variables.AddRange(expr.Variables);
args[i] = expr.FinalValue;
}
return(new ConstructedValueExpression(expressions, Expression.Call(null, factoryMethod, args), variables));
}
public static ConstructedValueExpression GetCollectionPopulateStatements(ICompiler scalars, ICompiler nonScalars, MapTypeContext context, Type elementType, Expression listVar, MethodInfo addMethod)
{
if (!context.HasColumns())
{
return(new ConstructedValueExpression(null));
}
var expressions = new List <Expression>();
var variables = new List <ParameterExpression>();
// For scalar types (object is treated like a scalar here), map each column to an entry in the
// array, consuming all remaining columns.
if (elementType.IsSupportedPrimitiveType() || elementType == typeof(object))
{
var columns = context.GetColumns();
foreach (var column in columns)
{
var columnState = context.GetSubstateForColumn(column, elementType, null);
var result = scalars.Compile(columnState);
expressions.AddRange(result.Expressions);
expressions.Add(
Expression.Call(
listVar,
addMethod,
result.FinalValue
)
);
variables.AddRange(result.Variables);
}
return(new ConstructedValueExpression(expressions, null, variables));
}
// For all non-scalar types
// loop so long as we have columns and consume columns every iteration.
var elementState = context.ChangeTargetType(elementType);
var numberOfColumns = context.NumberOfColumns();
while (numberOfColumns > 0)
{
var result = nonScalars.Compile(elementState);
var newNumberOfColumns = context.NumberOfColumns();
// We haven't consumed any new columns, so we're done.
if (newNumberOfColumns == numberOfColumns)
{
break;
}
expressions.AddRange(result.Expressions);
expressions.Add(
Expression.Call(listVar, addMethod, result.FinalValue)
);
variables.AddRange(result.Variables);
numberOfColumns = newNumberOfColumns;
}
return(new ConstructedValueExpression(expressions, null, variables));
}