---
title: "SE-0071: Allow (most) keywords in member references"
framework: swift-evolution
role: article
path: swift-evolution/0071-member-keywords
---

# SE-0071: Allow (most) keywords in member references

* Proposal: [SE-0071](0071-member-keywords.md)
* Author: [Doug Gregor](https://github.com/DougGregor)
* Review Manager: [Chris Lattner](https://github.com/lattner)
* Status: **Implemented (Swift 3.0)**
* Decision Notes: [Rationale](https://forums.swift.org/t/accepted-se-0071-allow-most-keywords-in-member-references/2421)

## Introduction

The [Swift API Design Guidelines](https://swift.org/documentation/api-design-guidelines/) consider enum cases as values that use the lowerCamelCase naming conventions. This means that case names that previously did not conflict with keywords (such as `Default`, `Private`, `Repeat`) now cause conflicts, a problem that is particularly acute when the naming conventions are applied by the Clang importer (per [SE-0005](0005-objective-c-name-translation.md)). To mitigate this issue, this proposal allows the use of most keywords after a ".", similarly to how [SE-0001](0001-keywords-as-argument-labels.md) allows keywords are argument labels.

* [\[Idea\] Allowing most keywords after "."](https://forums.swift.org/t/idea-allowing-most-keywords-after/1592) * [\[Review\] SE-0071: Allow (most) keywords in member references](https://forums.swift.org/t/review-se-0071-allow-most-keywords-in-member-references/2346)

## Motivation

[SE-0005](0005-objective-c-name-translation.md) started lower-camel-casing importer enum cases, which created a number of enum types whose names conflict with keywords. For example:

```swift enum UITableViewCellStyle : Int {   case \`default\`   case value1   case value2   case subtitle }

enum SCNParticleImageSequenceAnimationMode : Int {   case \`repeat\`   case clamp   case autoReverse } ```

The need to use back-ticks to declare the enumeration is not terribly onerous, especially given that these are Objective-C APIs with very-long names (`UITableViewCellStyleDefault`, `SCNParticleImageSequenceAnimationModeRepeat`). However, at the use site, the back-ticks are messy:

```swift let cell = UITableViewCell(style: .`default`, reuseIdentifier: nil) particleSystem.imageSequenceAnimationMode = SCNParticleImageSequenceAnimationMode.`repeat` ```

## Proposed solution

Allow the use of keywords after the `.` in a member access, except for those keywords that have special meaning in the language: `self`, `dynamicType`, `Type`, `Protocol`, (*note*: this list should track the evolution of the actual language). For example, the above example would become:

```swift let cell = UITableViewCell(style: .default, reuseIdentifier: nil) particleSystem.imageSequenceAnimationMode = SCNParticleImageSequenceAnimationMode.repeat ```

## Impact on existing code

This change doesn't break any existing code; the back-ticks will continue to work as they always have. As we did with [SE-0001](0001-keywords-as-argument-labels.md), we can provide warnings with Fix-Its that remove spurious back-ticks at use sites. While not semantically interesting, this helps developers clean up their code.