❯ python3 -c "print('1\n' * 532 + '\n' + ','.join(['1'] * 21))" > testfile

app [main] { pf: platform "https://github.com/roc-lang/basic-cli/releases/download/0.17.0/lZFLstMUCUvd5bjnnpYromZJXkQUrdhbva4xdBInicE.tar.br" }

import pf.Stdout
import pf.File

parseLine = \line ->
    line |> Str.splitOn "," |> List.mapTry Str.toI64

constructComesBefore = \elems ->
    List.walk
        elems
        (Dict.empty {})
        (\acc, a ->
            Dict.insert acc a (Set.empty {}))

parse = \s ->
    lines = Str.splitOn s "\n"
    split = List.findFirstIndex? lines (Str.isEmpty)
    ordering =
        List.takeFirst lines split
        |> List.mapTry? (\_ -> Ok 1)
        |> constructComesBefore
    pageNumbers =
        List.dropFirst lines (split + 1)
        |> List.dropIf Str.isEmpty
        |> List.mapTry? parseLine
    Ok { ordering, pageNumbers }

main =
    when File.readUtf8! "testfile" |> parse is
        Ok contents ->
            contents.pageNumbers
            |> List.len
            |> Num.toStr
            |> Stdout.line!

        Err _ -> Task.ok {}

❯ roc dev ./err.roc --linker=legacy
malloc(): unsorted double linked list corrupted

❯ roc version
roc nightly pre-release, built from commit 97ab13e on Mi 18 Dez 2024 09:02:06 UTC