https://github.com/thautwarm/fastparse.fs

fast, easy, typed, minimal
https://github.com/thautwarm/fastparse.fs

parser

Last synced: 7 months ago
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fast, easy, typed, minimal

• Host: GitHub
• URL: https://github.com/thautwarm/fastparse.fs
• Owner: thautwarm
• Created: 2018-09-03T07:54:58.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2018-09-06T08:12:04.000Z (over 7 years ago)
• Last Synced: 2025-04-09T15:50:23.730Z (10 months ago)
• Topics: parser
• Language: F#
• Homepage:
• Size: 22.5 KB
• Stars: 8
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

          
```F#

    open FastParse.Parser

    open FastParse.Lexer

    type sexpr = 

    | Term of string

    | S    of sexpr list

    (** auto lexer *)

    let lexer_tb = [

        R "term"  "[^\(\)\s]+"

        R "space" "\s+"

        C "unname" ["("]

        C "unname" [")"]

    ]

    let term : token parser = token_by_name "term"

    let l: token parser = token_by_value "("

    let r: token parser = token_by_value ")"

    let rec lisp tokens  =

        let l = 

            fun tokens ->

                let many: sexpr list parser = 

                    rep lisp 0 -1 <| fun lst -> lst

                let l: sexpr list parser =

                    both l many <| fun _ lst -> lst

                let r: sexpr parser = 

                    both l r    <| fun lst _ -> S lst

                r tokens

        let m: sexpr parser = map term <| fun it -> Term it.value

        either l m tokens 

    

    let filt = Seq.filter <| fun (it: token) -> it.name <> "space"

    

    let tokens = filt >> Array.ofSeq 

                 <| lex None lexer_tb 

                    {filename = ""

                     text = "(add 1 (mul 1 2 3))"}

    let tokens = {arr = tokens; offset = 0}

    

    let value = parse tokens lisp

    sprintf "%A" value

    (**

    output:

    S [Term "add"; Term "1"; S [Term "mul"; Term "1"; Term "2"; Term "3"]]

    *)

```