---
title: Publishers
framework: combine
role: symbol
role_heading: Enumeration
path: combine/publishers
---

# Publishers

A namespace for types that serve as publishers.

## Declaration

```swift
enum Publishers
```

## Overview

Overview The various operators defined as extensions on Publisher implement their functionality as classes or structures that extend this enumeration. For example, the contains(_:) operator returns a Publishers.Contains instance.

## Topics

### Convenience publishers

- [Publishers.Sequence](combine/publishers/sequence.md)
- [Publishers.Catch](combine/publishers/catch.md)

### Working with subscribers

- [Publishers.ReceiveOn](combine/publishers/receiveon.md)
- [Publishers.SubscribeOn](combine/publishers/subscribeon.md)

### Mapping elements

- [Publishers.Map](combine/publishers/map.md)
- [Publishers.TryMap](combine/publishers/trymap.md)
- [Publishers.MapError](combine/publishers/maperror.md)
- [Publishers.Scan](combine/publishers/scan.md)
- [Publishers.TryScan](combine/publishers/tryscan.md)
- [Publishers.SetFailureType](combine/publishers/setfailuretype.md)

### Filtering elements

- [Publishers.Filter](combine/publishers/filter.md)
- [Publishers.TryFilter](combine/publishers/tryfilter.md)
- [Publishers.CompactMap](combine/publishers/compactmap.md)
- [Publishers.TryCompactMap](combine/publishers/trycompactmap.md)
- [Publishers.RemoveDuplicates](combine/publishers/removeduplicates.md)
- [Publishers.TryRemoveDuplicates](combine/publishers/tryremoveduplicates.md)
- [Publishers.ReplaceEmpty](combine/publishers/replaceempty.md)
- [Publishers.ReplaceError](combine/publishers/replaceerror.md)

### Reducing elements

- [Publishers.Collect](combine/publishers/collect.md)
- [Publishers.CollectByCount](combine/publishers/collectbycount.md)
- [Publishers.CollectByTime](combine/publishers/collectbytime.md)
- [Publishers.TimeGroupingStrategy](combine/publishers/timegroupingstrategy.md)
- [Publishers.IgnoreOutput](combine/publishers/ignoreoutput.md)
- [Publishers.Reduce](combine/publishers/reduce.md)
- [Publishers.TryReduce](combine/publishers/tryreduce.md)

### Applying mathematical operations on elements

- [Publishers.Count](combine/publishers/count.md)
- [Publishers.Comparison](combine/publishers/comparison.md)
- [Publishers.TryComparison](combine/publishers/trycomparison.md)

### Applying matching criteria to elements

- [Publishers.Contains](combine/publishers/contains.md)
- [Publishers.ContainsWhere](combine/publishers/containswhere.md)
- [Publishers.TryContainsWhere](combine/publishers/trycontainswhere.md)
- [Publishers.AllSatisfy](combine/publishers/allsatisfy.md)
- [Publishers.TryAllSatisfy](combine/publishers/tryallsatisfy.md)

### Applying sequence operations to elements

- [Publishers.DropUntilOutput](combine/publishers/dropuntiloutput.md)
- [Publishers.Drop](combine/publishers/drop.md)
- [Publishers.DropWhile](combine/publishers/dropwhile.md)
- [Publishers.TryDropWhile](combine/publishers/trydropwhile.md)
- [Publishers.Concatenate](combine/publishers/concatenate.md)
- [Publishers.PrefixWhile](combine/publishers/prefixwhile.md)
- [Publishers.TryPrefixWhile](combine/publishers/tryprefixwhile.md)
- [Publishers.PrefixUntilOutput](combine/publishers/prefixuntiloutput.md)

### Selecting specific elements

- [Publishers.First](combine/publishers/first.md)
- [Publishers.FirstWhere](combine/publishers/firstwhere.md)
- [Publishers.TryFirstWhere](combine/publishers/tryfirstwhere.md)
- [Publishers.Last](combine/publishers/last.md)
- [Publishers.LastWhere](combine/publishers/lastwhere.md)
- [Publishers.TryLastWhere](combine/publishers/trylastwhere.md)
- [Publishers.Output](combine/publishers/output.md)

### Combining elements from multiple publishers

- [Publishers.CombineLatest](combine/publishers/combinelatest.md)
- [Publishers.CombineLatest3](combine/publishers/combinelatest3.md)
- [Publishers.CombineLatest4](combine/publishers/combinelatest4.md)
- [Publishers.Merge](combine/publishers/merge.md)
- [Publishers.Merge3](combine/publishers/merge3.md)
- [Publishers.Merge4](combine/publishers/merge4.md)
- [Publishers.Merge5](combine/publishers/merge5.md)
- [Publishers.Merge6](combine/publishers/merge6.md)
- [Publishers.Merge7](combine/publishers/merge7.md)
- [Publishers.Merge8](combine/publishers/merge8.md)
- [Publishers.MergeMany](combine/publishers/mergemany.md)
- [Publishers.Zip](combine/publishers/zip.md)
- [Publishers.Zip3](combine/publishers/zip3.md)
- [Publishers.Zip4](combine/publishers/zip4.md)

### Republishing elements by subscribing to new publishers

- [Publishers.FlatMap](combine/publishers/flatmap.md)
- [Publishers.SwitchToLatest](combine/publishers/switchtolatest.md)

### Handling errors

- [Publishers.AssertNoFailure](combine/publishers/assertnofailure.md)
- [Publishers.Catch](combine/publishers/catch.md)
- [Publishers.TryCatch](combine/publishers/trycatch.md)
- [Publishers.Retry](combine/publishers/retry.md)

### Controlling timing

- [Publishers.MeasureInterval](combine/publishers/measureinterval.md)
- [Publishers.Debounce](combine/publishers/debounce.md)
- [Publishers.Delay](combine/publishers/delay.md)
- [Publishers.Throttle](combine/publishers/throttle.md)
- [Publishers.Timeout](combine/publishers/timeout.md)

### Encoding and decoding

- [Publishers.Decode](combine/publishers/decode.md)
- [Publishers.Encode](combine/publishers/encode.md)

### Identifying properties with key paths

- [Publishers.MapKeyPath](combine/publishers/mapkeypath.md)
- [Publishers.MapKeyPath2](combine/publishers/mapkeypath2.md)
- [Publishers.MapKeyPath3](combine/publishers/mapkeypath3.md)

### Working with multiple subscribers

- [Publishers.Multicast](combine/publishers/multicast.md)
- [Publishers.Share](combine/publishers/share.md)

### Buffering elements

- [Publishers.Buffer](combine/publishers/buffer.md)
- [Publishers.BufferingStrategy](combine/publishers/bufferingstrategy.md)
- [Publishers.PrefetchStrategy](combine/publishers/prefetchstrategy.md)

### Using explicit publisher connections

- [Publishers.Autoconnect](combine/publishers/autoconnect.md)
- [Publishers.MakeConnectable](combine/publishers/makeconnectable.md)

### Debugging

- [Publishers.Breakpoint](combine/publishers/breakpoint.md)
- [Publishers.HandleEvents](combine/publishers/handleevents.md)
- [Publishers.Print](combine/publishers/print.md)

## See Also

### Publishers

- [Publisher](combine/publisher.md)
- [AnyPublisher](combine/anypublisher.md)
- [Published](combine/published.md)
- [Cancellable](combine/cancellable.md)
- [AnyCancellable](combine/anycancellable.md)