public object GetValue(IMemberExpression expression, object origin, Action <MemberContext> evaluate = null)
{
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
var result = origin;
MemberContext context = new MemberContext(0, origin, origin, expression);
while (context != null)
{
context.Member = this.GetMember(context);
evaluate?.Invoke(context);
if (!context.HasValue)
{
context.Value = this.GetMemberValue(context);
}
result = context.Value;
context = context.Next();
}
return(result);
}
public static void VisitMemberExpressionChildren<TExpression>(
IMemberExpression<TExpression> memberExpression,
IGenericExpressionVisitor visitor)
where TExpression : IExpression
{
GenericExpressionChildVisitor.VisitMemberExpressionChildren<IMemberExpression<TExpression>, TExpression, IGenericExpressionVisitor>(memberExpression, visitor);
}
public void SetValue(IMemberExpression expression, object origin, Func <MemberContext, object> valueFactory, Action <MemberContext> evaluate = null)
{
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
if (valueFactory == null)
{
throw new ArgumentNullException(nameof(valueFactory));
}
var context = new MemberContext(0, origin, origin, expression);
while (context.HasNext)
{
context.Member = this.GetMember(context);
evaluate?.Invoke(context);
if (!context.HasValue)
{
context.Value = this.GetMemberValue(context);
}
context = context.Next();
}
context.Member = this.GetMember(context);
evaluate?.Invoke(context);
context.Value = valueFactory(context);
this.SetMemberValue(context);
}
public override void VisitMemberExpression <TExpression>(IMemberExpression <TExpression> memberExpression)
{
Value = new Expression()
{
MemberExpression = new MemberExpressionFactory(memberExpression).Value
};
}
public void AppendParameterConstant(IMemberExpression owner)
{
if (owner == null)
{
throw new InvalidOperationException(EXCEPTION_UNKNOWN_MESSAGE);
}
void Add(ICollection <IMemberExpression> parameters, string content, TypeCode type)
{
parameters.Add(MemberExpression.Constant(content, type));
};
if (owner is IndexerExpression indexer)
{
Add(indexer.Arguments, GetBufferContent(), Flags.GetConstantType());
}
else if (owner is MethodExpression method)
{
Add(method.Arguments, GetBufferContent(), Flags.GetConstantType());
}
else
{
throw new InvalidOperationException(EXCEPTION_UNKNOWN_MESSAGE);
}
}
public MemberContext(int index, object origin, object target, IMemberExpression expression)
{
this.Depth = 0;
this.Index = index;
this.Origin = origin;
this.Owner = target;
this.Expression = expression;
this.Member = null;
this.Parameters = null;
}
public T Prepend <T>(T expression) where T : MemberExpression
{
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
_previous = expression;
expression._next = this;
return(expression);
}
public HierarchicalExpression(PathAnchor anchor, string[] segments, IMemberExpression accessor)
{
this.Anchor = anchor;
this.Accessor = accessor;
this.Segments = segments ?? Array.Empty <string>();
switch (anchor)
{
case PathAnchor.Root:
if (segments == null || segments.Length == 0)
{
this.Path = HierarchicalNode.PathSeparatorChar.ToString();
}
else
{
this.Path = HierarchicalNode.PathSeparatorChar + string.Join(HierarchicalNode.PathSeparatorChar, segments);
}
break;
case PathAnchor.Current:
if (segments == null || segments.Length == 0)
{
this.Path = ".";
}
else
{
this.Path = "." + HierarchicalNode.PathSeparatorChar + string.Join(HierarchicalNode.PathSeparatorChar, segments);
}
break;
case PathAnchor.Parent:
if (segments == null || segments.Length == 0)
{
this.Path = "..";
}
else
{
this.Path = ".." + HierarchicalNode.PathSeparatorChar + string.Join(HierarchicalNode.PathSeparatorChar, segments);
}
break;
default:
if (segments == null || segments.Length == 0)
{
this.Path = string.Empty;
}
else
{
this.Path = string.Join(HierarchicalNode.PathSeparatorChar, Segments);
}
break;
}
}
public IdentifierExpression AppendIdentifier(IMemberExpression owner)
{
var current = MemberExpression.Identifier(GetBufferContent());
if (owner == null)
{
if (Head == null)
{
Head = current;
}
else
{
Head = Head.Append(current);
}
return(current);
}
if (owner is IndexerExpression indexer)
{
if (Flags.IsAttaching())
{
if (indexer.Arguments.Count == 0 || indexer.Arguments[indexer.Arguments.Count - 1].ExpressionType != MemberExpressionType.Identifier)
{
throw new InvalidOperationException(EXCEPTION_UNKNOWN_MESSAGE);
}
return(((MemberExpression)((IdentifierExpression)indexer.Arguments[indexer.Arguments.Count - 1]).Last()).Append(current));
}
indexer.Arguments.Add(current);
return(current);
}
else if (owner is MethodExpression method)
{
if (Flags.IsAttaching())
{
if (method.Arguments.Count == 0 || method.Arguments[method.Arguments.Count - 1].ExpressionType != MemberExpressionType.Identifier)
{
throw new InvalidOperationException(EXCEPTION_UNKNOWN_MESSAGE);
}
return(((MemberExpression)((IdentifierExpression)method.Arguments[method.Arguments.Count - 1]).Last()).Append(current));
}
method.Arguments.Add(current);
return(current);
}
throw new InvalidOperationException(EXCEPTION_UNKNOWN_MESSAGE);
}
/// <summary>
/// 查找指定表达式节点位于表达式中的最末节点元素。
/// </summary>
/// <param name="expression">指定的要查找的表达式节点。</param>
/// <returns>返回的最末表达式元素。</returns>
public static IMemberExpression Last(this IMemberExpression expression)
{
if (expression == null)
{
return(null);
}
while (expression.Next != null)
{
expression = expression.Next;
}
return(expression);
}
/// <summary>
/// 查找指定表达式节点位于表达式中的首个节点元素。
/// </summary>
/// <param name="expression">指定的要查找的表达式节点。</param>
/// <returns>返回的首个表达式元素。</returns>
public static IMemberExpression First(this IMemberExpression expression)
{
if (expression == null)
{
return(null);
}
while (expression.Previous != null)
{
expression = expression.Previous;
}
return(expression);
}
public static bool TryParse(string text, int start, int count, out IMemberExpression expression)
{
return((expression = Parse(text, start, count, null)) != null);
}
public virtual void VisitMemberExpression <TExpression>(IMemberExpression <TExpression> memberExpression)
where TExpression : IExpression
{
Visit(memberExpression);
}
public void SetValue(IMemberExpression expression, object origin, object value, Action <MemberContext> evaluate = null)
{
this.SetValue(expression, origin, _ => value, evaluate);
}
public override void VisitMemberExpression <TExpression>(IMemberExpression <TExpression> memberExpression)
{
Steps.Add(new WriteExpression <TExpression>(memberExpression.ObjectExpression));
Steps.Add(new WriteDot());
Steps.Add(new WriteName(memberExpression.MemberName));
}
public static bool TryParse(string text, out IMemberExpression expression)
{
return((expression = Parse(text, 0, 0, null)) != null);
}
internal static Type GetMemberType(IMemberExpression expression, Type originType)
{
if (originType == null)
{
throw new ArgumentNullException(nameof(originType));
}
if (expression == null)
{
return(originType);
}
var element = expression;
var elementType = originType;
while (element != null)
{
switch (element.ExpressionType)
{
case MemberExpressionType.Constant:
elementType = ((ConstantExpression)element).Value?.GetType();
break;
case MemberExpressionType.Identifier:
var identifier = (IdentifierExpression)element;
elementType = elementType.GetProperty(identifier.Name)?.PropertyType ??
elementType.GetField(identifier.Name)?.FieldType;
break;
case MemberExpressionType.Indexer:
var memberName = elementType.GetCustomAttribute <DefaultMemberAttribute>()?.MemberName;
if (string.IsNullOrEmpty(memberName))
{
throw new InvalidOperationException("");
}
elementType = elementType.GetProperty(memberName)?.PropertyType;
break;
case MemberExpressionType.Method:
var method = (MethodExpression)element;
if (method.HasArguments)
{
var parameterTypes = new Type[method.Arguments.Count];
for (var i = 0; i < method.Arguments.Count; i++)
{
parameterTypes[i] = GetMemberType(method.Arguments[i], originType);
}
elementType = elementType.GetMethod(method.Name, parameterTypes)?.ReturnType;
}
else
{
elementType = elementType.GetMethod(method.Name)?.ReturnType;
}
break;
}
element = element.Next;
}
return(elementType);
}
