public static BlockExpression MergeBlocks(Expression expr1, Expression expr2)
{
IEnumerable <ParameterExpression> variables = new ParameterExpression[0];
IEnumerable <Expression> body = new Expression[0];
if (expr1 is BlockExpression block1)
{
body = body.Concat(block1.Expressions);
variables = variables.Concat(block1.Variables);
}
else
{
body = body.Append(expr1);
}
if (expr2 is BlockExpression block2)
{
body = body.Concat(block2.Expressions);
variables = variables.Concat(block2.Variables);
}
else
{
body = body.Append(expr2);
}
return(Block(variables.Distinct(), body));
}
private static TDelegate DelegateIndexerSet <TDelegate>(Type source, Type returnType,
params Type[] indexTypes)
where TDelegate : class
{
//TODO: check if returnType value is correct
var indexerInfo = source.GetIndexerPropertyInfo(indexTypes);
if (indexerInfo?.SetMethod == null)
{
return(null);
}
ParameterExpression sourceObjectParam;
if (source.IsClassType() || source.GetTypeInfo().IsInterface)
{
sourceObjectParam = Expression.Parameter(typeof(object), "source");
}
else
{
sourceObjectParam = Expression.Parameter(typeof(object).MakeByRefType(), "source");
}
var valueParam = Expression.Parameter(returnType, "value");
var indexExpressions = new ParameterExpression[indexTypes.Length];
for (var i = 0; i < indexTypes.Length; i++)
{
var indexType = indexTypes[i];
indexExpressions[i] = Expression.Parameter(indexType, "i" + i);
}
var callArgs = indexExpressions.Concat(new[] { valueParam }).ToArray();
var paramsExpressions = new[] { sourceObjectParam }.Concat(callArgs);
Expression blockExpr;
if (!(source.IsClassType() || source.GetTypeInfo().IsInterface))
{
#if !NET35
var structVariable = Expression.Variable(source, "struct");
blockExpr = Expression.Block(typeof(object), new[] { structVariable },
Expression.Assign(structVariable, Expression.Convert(sourceObjectParam, source)),
Expression.Call(structVariable, indexerInfo.SetMethod, callArgs),
Expression.Assign(sourceObjectParam, Expression.Convert(structVariable, typeof(object)))
);
#else
throw new ArgumentException("This is not supported for structures in .NET 3.5");
#endif
}
else
{
blockExpr = Expression.Call(Expression.Convert(sourceObjectParam, source),
indexerInfo.SetMethod, callArgs);
}
return(Expression.Lambda <TDelegate>(blockExpr, paramsExpressions).Compile());
}
// Indexer Set
private static Delegate DelegateIndexerSet(Type source, Type valueType, params Type[] indexTypes)
{
var propertyInfo = source.GetProperty(Item, valueType, indexTypes);
if (propertyInfo == null)
{
return(null);
}
var sourceObjectParam = Expression.Parameter(typeof(object), "source");
var valueParam = Expression.Parameter(valueType, "value");
var indexExpressions = new ParameterExpression[indexTypes.Length];
for (var i = 0; i < indexTypes.Length; i++)
{
indexExpressions[i] = Expression.Parameter(indexTypes[i], "index");
}
var callArgs = indexExpressions.Concat(new[] { valueParam }).ToArray();
var paramsExpressions = new[] { sourceObjectParam }.Concat(callArgs).ToArray();
return(Expression.Lambda(Expression.Call(Expression.Convert(sourceObjectParam, source), propertyInfo.GetSetMethod(), callArgs), paramsExpressions).Compile());
}