What is this function for exactly? Without the use case it is not clear that this function produces the right string.

Either way I think you should split the function into two functions -- one to get the string and one to get the kind.

The use case is essentially unparse - this is for formatting ocamldoc comments. The AST returned by the parser contains Reference.ts and we need to convert it back to a string to insert in the reformatted text.

Another suggestion was to keep the original string in the AST, but on reflection that didn't look right. I suppose another possibility is to use the location info in the AST to get it from the original string too.

The AST returned by the parser contains Reference.ts

I suspect this is the problem. Really the parser should produce something that is pretty close to one-to-one with the syntax and we should translate them into Reference.ts when we store the information into the things in Lang. Reference.ts don't keep enough information for re-printing them as they were, and maintaining that information when processing them would be annoying.

The function could be made a little more useful by returning the list of component, the kind and the label: : t -> string list * tag_any * string option and allow the user to concatenate it.

Otherwise in #351, I suggest to expose Parser_.Ast and later to simplify it. This is one of the simplifications I had in mind. What do you think ?

The function could be made a little more useful by returning the list of component, the kind and the label: : t -> string list * tag_any * string option and allow the user to concatenate it.

I don't think this does what you want for a reference like:

Foo.module-type-Bar.t

The last part of the reference is not the only part that has a meaningful kind.

Also, you'll conflate:

Foo.type-t

with

type:Foo.t

which I imagine you'd prefer not to do (assuming you are trying to print the comments as they were written, rather than trying to normalize them).

I see. Returning the type of each part is also not good because it would be too hard to known what should be printed and how.