Learning some Fantomas AST

Made a test encoder/decored for a simple namespace declaration with Fantomas OAK Ast, see fantomas tools page

given

Oak (1,0-1,15)
        ModuleOrNamespaceNode (1,0-1,15)
            ModuleOrNamespaceHeaderNode (1,0-1,15)
                MultipleTextsNode (1,0-1,9)
                    namespace (1,0-1,9)
                IdentListNode (1,10-1,15)
                    A (1,10-1,11)
                    B (1,12-1,13)
                    C (1,14-1,15)

it will output A.B.C (lowered)

you can run it as dotnet fsi script.fsx or in vscode with dotnet sdk installed. cheers!

let oakAst = 
    "hello.one.two"
    |> FantomasWriter.makeNamespace  []

oakAst 
|> FantomasReader.extractNsFromOak 
|> Option.iter (printfn "NAMESPACE: %s")

Fabulous.AST

if you want to make your life easier and drop the custom write part for Oak, you can make use of the awesome Fabulous.AST DSL nuget package

#r "nuget:Fabulous.AST"

open System
open Fabulous.AST
open type Fabulous.AST.Ast

// using Fabulous.AST life becomes easier for writing oak
let oakAst = 
    Ast.Oak(){
        Ast.Namespace("hello.one.two") {}
    }
    |> Gen.mkOak

Here a Gist of It