I have a token sequence. No I need to write a parser consuming the sequence. The abbreviated version of the parser can be soethoing like this:

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let rec parse (nodes:Node list) (tokens : Token seq) =

   let token = Seq.hd tokens

   //Advance the tokens by one

   .....

 

   let new_nodes, leftover_tokens = parse_token tokens token

   parse (nodes @ new_nodes) leftover_tokens

The question here is how do I advance the token sequence? Doing this with Seq.skip 1 would seem to do the trick, but I guess that the new sequence created this way will keep repeating skipping every time the sequence is acessed, effectively making this process O(n^2).

So what's the way to deal with this?

one more thing: parse_token can recurisevely call parse which can advance the tokens sequence further, therefore straightforward Seq.fold over the token sequence would not work here