private IEnumerable <(string typeName, string attributeCreator)> CollectAttributedTypes(
ICompilingContext context)
{
var collected =
from type in context.Assembly.GetTypes()
let attribute = (CompileAttribute)type.Attributes.FirstOrDefault(a => a.Match(_attributeType))
where attribute != null
select(type, attribute);
foreach (var(type, attribute) in collected)
{
if (attribute.GetValues().Union(attribute.GetProperties().Select(x => x.value))
.Any(x => x.Contains("typeof")))
{
RequireNamespaces(type.UsingNamespaceList.Union(new[] { type.Namespace }));
}
yield return(type.FullName, ToCreator(attribute));
}
}
public CompileCodeSnippetBuilder(ICompilingContext context)
{
_context = context ?? throw new ArgumentNullException(nameof(context));
}
/// <summary>
/// 执行占位符对 <see cref="Placeholder"/> 中外部方法（extern）的调用，得到代码片段字符串。
/// </summary>
/// <param name="placeholderInfo">包含表达式树中解析出来的占位符信息。</param>
/// <param name="context">编译期代码执行所需的上下文信息。</param>
/// <returns>占位符中的编译期代码执行后得到的代码片段字符串。</returns>
internal static string Execute(this PlaceholderVisitor.PlaceholderInfo placeholderInfo, ICompilingContext context)
{
var lambda = placeholderInfo.Compile();
var codeSnippet = lambda(context);
codeSnippet = placeholderInfo.Wrap(codeSnippet);
return(codeSnippet);
}
