PidginFsharp

F# port of the Pidgin parser combinator library. It builds on the same primitive parsers and combinators described in the Pidgin documentation

This port was started mainly as a practice project to learn more about F# programming, it's not intended for production use yet due to features of Pidgin still missing, and there has been no focus put on performance. If you're looking for a production-ready parser library and can use C#, then you can use the original Pidgin, or if you're looking for a mature and performant library in F#, take a look at FParsec.

Examples

To illustrate the sytax being used, here are a couple of examples.

Parse a single 'a' character.

let parser = token 'a'

Parse a digit and a letter after each other.

let parser =
    [ tokenPred Char.IsDigit
      tokenPred Char.IsLetter ]
    |> sequence

Parse a list of digit characters between an opening and closing parenthesis.

let parser =
    tokenPred Char.IsDigit
    |> separated (token ',')
    |> between (token '(') (token ')')

Parse a list of integers between an opening and closing parenthesis, and actually return the parsed integer values.

let integer =
    tokenPred Char.IsDigit
    |> atLeastOnce
    |> select (String.Concat >> Int32.Parse)

let parser =
    integer
    |> separated (token ',')
    |> between (token '(') (token ')')

A recursive example (the same one from the Pidgin docs), matching a single digit between an equal number of closing and opening parantheses.

let rec parenthesised state =
    digitInsideParens
    |> between (token '(') (token ')') <| state
and digitInsideParens state =
    either (tokenPred Char.IsDigit) parenthesised <| state

You can find many more small examples in the unit test project, and a more complex one is a simple Json parser.