Hi,

My current project involves lexing and parsing script code, and as such I'm using fslex and fsyacc. Fslex LexBuffers can come in either LexBuffer<char> and LexBuffer<byte> varieties, and I'd like to have the option to use both.

In order to user both, I need a lexeme function of type ^buf -> string. Thus far, my attempts at specialization have looked like:

let inline lexeme (lexbuf: ^buf) : ^buf -> string where ^buf : (member Lexeme: char array) =
  new System.String(lexbuf.Lexeme)

let inline lexeme (lexbuf: ^buf) : ^buf -> string where ^buf : (member Lexeme: byte array) =
  System.Text.Encoding.UTF8.GetString(lexbuf.Lexeme)

I'm getting a type error stating that the function body should be of type ^buf -> string, but the inferred type is just string. Clearly, I'm doing something (majorly?) wrong.

Is what I'm attempting even possible in F#? If so, can someone point me to the proper path?

Thanks!