OneOf?

未关闭
#68 4 条评论 0 个 reaction 已指派 0 人 在 GitHub 查看

还没有人认领这个 Issue。

评估

难度
2/5
预计耗时
1-3 小时
新手友好度
35/100
Issue 类型
功能
描述清晰度
基本清楚
活跃度
停滞
领域
backend

调研方向

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.

由索引模型根据 Issue 内容生成。

描述

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.

主要语言
PureScript
星标
64
派生
42
平均合并
2 天 6 小时
30 天内合并 PR
1

环境准备

  • 没有 Dockerfile 或 Docker Compose 文件
  • 有 Pull Request 模板
  • 没有贡献指南

从这里开始

  1. 先读完整个 Issue,再读项目的贡献指南。
  2. 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
  3. Fork 仓库,在一个分支上完成修改。
  4. 提交 Pull Request,并在描述里引用这个 Issue 编号。

相似的 Issue

更多 Backend & API Design Issue

把新 issue 发到你的邮箱

精选适合新手参与的 GitHub issue 摘要。