function atBreak(code) {
    if (code === codes.eof) {
      return after(code)
    }

    if (markdownLineEnding(code)) {
      return effects.attempt(furtherStart, atBreak, after)(code)
    }

    effects.enter(types.codeFlowValue)
    return inside(code)
  }
At a break.

```markdown
> |     aaa
        ^  ^
```

@type {State}