---
title: LazyMapSequence
framework: swift
role: symbol
role_heading: Structure
path: swift/lazymapsequence
---

# LazyMapSequence

A Sequence whose elements consist of those in a Base Sequence passed through a transform function returning Element. These elements are computed lazily, each time they’re read, by calling the transform function on a base element.

## Declaration

```swift
@frozen struct LazyMapSequence<Base, Element> where Base : Sequence
```

## Topics

### Instance Methods

- [map(_:)](swift/lazymapsequence/map(_:)-2qa3r.md)
- [map(_:)](swift/lazymapsequence/map(_:)-50gkd.md)

### Type Aliases

- [LazyMapSequence.Elements](swift/lazymapsequence/elements.md)

### Default Implementations

- [BidirectionalCollection Implementations](swift/lazymapsequence/bidirectionalcollection-implementations.md)
- [Collection Implementations](swift/lazymapsequence/collection-implementations.md)
- [LazySequenceProtocol Implementations](swift/lazymapsequence/lazysequenceprotocol-implementations.md)
- [RandomAccessCollection Implementations](swift/lazymapsequence/randomaccesscollection-implementations.md)
- [Sequence Implementations](swift/lazymapsequence/sequence-implementations.md)

## Relationships

### Conforms To

- [BidirectionalCollection](swift/bidirectionalcollection.md)
- [Collection](swift/collection.md)
- [Copyable](swift/copyable.md)
- [Escapable](swift/escapable.md)
- [LazyCollectionProtocol](swift/lazycollectionprotocol.md)
- [LazySequenceProtocol](swift/lazysequenceprotocol.md)
- [RandomAccessCollection](swift/randomaccesscollection.md)
- [Sequence](swift/sequence.md)

## See Also

### Lazy Wrappers

- [LazySequence](swift/lazysequence.md)
- [LazyFilterSequence](swift/lazyfiltersequence.md)
- [LazyPrefixWhileSequence](swift/lazyprefixwhilesequence.md)
- [LazyDropWhileSequence](swift/lazydropwhilesequence.md)
- [LazyCollection](swift/lazycollection.md)
- [LazyDropWhileCollection](swift/lazydropwhilecollection.md)
- [LazyFilterCollection](swift/lazyfiltercollection.md)
- [LazyMapCollection](swift/lazymapcollection.md)
- [LazyPrefixWhileCollection](swift/lazyprefixwhilecollection.md)