OneOf?

Abierto
#68 4 comentarios 0 reacciones 0 asignados Ver en GitHub

Nadie ha tomado este issue todavía.

Evaluación

Dificultad
2/5
Tiempo estimado
1-3 horas
Aptitud para principiantes
35/100
Tipo de issue
Nueva funcionalidad
Claridad
Bastante claro
Estado de actividad
Estancado
Área
backend

Línea de trabajo

Start by reading the existing parser alternatives and error-combination operators in the library to see whether they already provide lazy, as-needed parsing. The issue includes a proposed oneOf implementation but names no files or tests; identify the relevant entry points and tests before deciding whether a new helper is needed. Done means establishing whether the helper exists or, if it does not, adding and testing the proposed behavior.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

status: needs more info

Feels like we probably already have a oneOf function that can make sure that not all branches are evaluated at once (to ensure efficient as-needed parsing), since using alt naively can lead to really really slow decoding, but I honestly don't know where it is. Is there something I'm missing that already implements this?:

oneOf :: forall f a
   . Foldable f
  => f (Foreign -> F a)
  -> Foreign
  -> F a
oneOf f js = go (fromFoldable f) js
  where
    go (read : xs) js = do
      case runExcept (read js) of
        Right pv -> pure pv
        Left e -> do
          case runExcept (go xs js) of
            Right pv' -> pure pv'
            Left e' -> throwError (e <> e')
    go Nil _ = do
      throwError $ pure (ForeignError "No more parsers to attempt in oneOf")

If not, I could PR this, but feels like it probably exists as a simple combination of some operators.

Lenguaje dominante
PureScript
Estrellas
64
Forks
42
Merge medio
2 d 6 h
PR fusionados (30 d)
1

Preparar el entorno

  • Sin Dockerfile ni archivo de Docker Compose
  • Tiene una plantilla de pull request
  • Sin guía de contribución

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. Abre un pull request que haga referencia al número del issue.

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