add dotnet_{api,version}

Author: scivision

+stdlib/dotnet_api.m

@@ -0,0 +1,7 @@
+%% DOTNET_API major version integer .NET 
+
+function v = dotnet_api()
+
+v = System.Environment.Version.Major;
+
+end

+stdlib/dotnet_version.m

@@ -0,0 +1,9 @@
+%% DOTNET_VERSION version string
+
+function v = dotnet_version()
+
+vs = System.Environment.Version;
+
+v = sprintf('%d.%d.%d', vs.Major, vs.Minor, vs.Build);
+
+end

+stdlib/is_symlink.m

@@ -12,7 +12,14 @@
   switch e.identifier
     case "MATLAB:UndefinedFunction"
       if stdlib.has_dotnet()
-        ok = is_symlink_dotnet(p);
+        if stdlib.dotnet_api >= 6
+          ok = ~isempty(System.IO.FileInfo(p).LinkTarget);
+        else
+           attr = string(System.IO.File.GetAttributes(p).ToString());
+           % https://learn.microsoft.com/en-us/dotnet/api/system.io.fileattributesN
+           % ReparsePoint is for Linux, macOS, and Windows
+           ok = contains(attr, 'ReparsePoint');
+        end
       elseif stdlib.has_java()
         ok = java.nio.file.Files.isSymbolicLink(javaPathObject(stdlib.absolute(p)));
       else
@@ -29,23 +36,6 @@
 end
 
 
-function ok = is_symlink_dotnet(p)
-
-try
-  ok = ~isempty(System.IO.FileInfo(p).LinkTarget);
-catch e
-  if strcmp(e.identifier, "MATLAB:noSuchMethodOrField")
-   attr = string(System.IO.File.GetAttributes(p).ToString());
-   % https://learn.microsoft.com/en-us/dotnet/api/system.io.fileattributesN
-   % ReparsePoint is for Linux, macOS, and Windows
-   ok = contains(attr, 'ReparsePoint');
-  else
-    rethrow(e)
-  end
-end
-
-end
-
 %!test
 %! if !ispc
 %! p = tempname();