---
title: "init(upstream:_:)"
framework: combine
role: symbol
role_heading: Initializer
path: "combine/publishers/maperror/init(upstream:_:)"
---

# init(upstream:_:)

## Declaration

```swift
init(upstream: Upstream, _ map: @escaping (Upstream.Failure) -> Failure)
```

## See Also

### Creating an error-mapping publisher

- [init(upstream:transform:)](combine/publishers/maperror/init(upstream:transform:).md)