roc/examples/csv/main.roc
2022-07-16 23:18:16 +02:00

54 lines
2.1 KiB
Plaintext

app "main"
packages { pf: "platform/main.roc" }
imports [Parser.Core.{Parser, map, apply}, Parser.Str.{RawStr}, Parser.CSV.{CSV, record, field, string, nat}]
provides [main] to pf
input = "Airplane!,1980,\"Robert Hays,Julie Hagerty\"\r\nCaddyshack,1980,\"Chevy Chase,Rodney Dangerfield,Ted Knight,Michael O'Keefe,Bill Murray\"\r\n"
main =
when Parser.CSV.parseStr movieInfoParser input is
Ok movies ->
moviesString =
movies
|> List.map movieInfoExplanation
|> Str.joinWith("\n")
nMovies = List.len movies |> Num.toStr
"Parse success! \(nMovies) movies were found:\n\n\(moviesString)\n"
Err problem ->
when problem is
ParsingFailure failure ->
"Parsing failure: \(failure)\n"
ParsingIncomplete leftover ->
leftoverStr = leftover |> List.map Parser.Str.strFromRaw |> List.map (\val -> "\"\(val)\"") |> Str.joinWith ", "
"Parsing incomplete. Following leftover fields while parsing a record: \(leftoverStr)\n"
SyntaxError error ->
"Parsing failure. Syntax error in the CSV: \(error)"
MovieInfo := {title: Str, releaseYear: Nat, actors: List Str}
movieInfoParser =
record (\title -> \releaseYear -> \actors -> @MovieInfo {title, releaseYear, actors})
|> apply (field string)
|> apply (field nat)
|> apply (field actorsParser)
actorsParser =
string
|> map (\val -> Str.split val ",")
movieInfoExplanation = \@MovieInfo {title, releaseYear, actors} ->
enumeratedActors = enumerate actors
releaseYearStr = Num.toStr releaseYear
"The movie '\(title)' was released in \(releaseYearStr) and stars \(enumeratedActors)"
enumerate : List Str -> Str
enumerate = \elements ->
{before: inits, others: last} = List.split elements (List.len elements - 1)
last
|> List.prepend (inits |> Str.joinWith ", ")
|> Str.joinWith " and "
# movieInfoToStr = \@MovieInfo {title, releaseYear, actors} ->
# releaseYearStr = Num.toStr releaseYear
# actorsStr = actors |> Str.joinWith ", "
# "MovieInfo {title: \(title), releaseYear: \(releaseYearStr)}, actors: [\(actorsStr))]}"