---
title: "CompositionLocalMap"
description: "A read-only, immutable snapshot of the [CompositionLocals][CompositionLocal] that are set at a
specific position in the composition hierarchy."
type: "interface"
---

<div class='type'>Interface</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>



```kotlin
public sealed interface CompositionLocalMap
```


A read-only, immutable snapshot of the `CompositionLocals` that are set at a
specific position in the composition hierarchy.


## Functions

```kotlin
public operator fun <T> get(key: CompositionLocal<T>): T
```


Returns the value of the provided `composition local` at the position in the composition
hierarchy represented by this `CompositionLocalMap` instance. If the provided `key` is not
set at this point in the hierarchy, its default value will be used.

For `non-static CompositionLocals`, this function will return the latest
value of the CompositionLocal, which might change over time across the same instance of the
CompositionLocalMap. Reads done in this way are not tracked in the snapshot system.

For `static CompositionLocals`, this function returns the value at
the time of creation of the CompositionLocalMap. When a static CompositionLocal is
reassigned, the entire composition hierarchy is recomposed and a new CompositionLocalMap is
created with the updated value of the static CompositionLocal.