aoc2017-day16-parser-choice.fs

#r "packages/FParsec/lib/net40-client/FParsecCS.dll"
#r "packages/FParsec/lib/net40-client/FParsec.dll"
open FParsec

type Operation =
    | Spin of int
    | Exchange of int * int
    | Partner of char * char

type ParserState = unit

let pspin : Parser<Operation,ParserState> = 
    pchar 's' >>. pint32 |>> Spin

let pexchange = 
    pchar 'x' 
      >>. tuple2 (pint32 .>> pchar '/') pint32 
      |>> Exchange

let ppartner = 
    pchar 'p' 
      >>. tuple2 (asciiLetter .>> pchar '/') asciiLetter 
      |>> Partner

let parseOperation = choice [ pspin; pexchange; ppartner ]

let parseOperations = run (sepBy parseOperation (pstring ","))

"po/k,x4/0,s12,x7/6" |> parseOperations
// Success: [Partner ('o','k'); Exchange (4,0); Spin 12; Exchange (7,6)]