swiftlang/swift

[SR-7152] Investigate a Better Collection for CaseIterable Synthesis

Open

#49,700 opened on Mar 9, 2018

View on GitHub
 (1 comment) (0 reactions) (0 assignees)Swift (69,989 stars) (10,719 forks)batch import
compilergood first issueimprovement

Description
Previous ID SR-7152
Radar None
Original Reporter @CodaFi
Type Improvement
Votes 0
Component/s Compiler
Labels Improvement, StarterBug
Assignee None
Priority Medium

md5: a133635420a390cef5a90e74eb062506

Issue Description:

As of this issue, the derived collection is an Array. We should investigate more effective collections before the final branch date for Swift 4.2/5

Contributor guide

Tech stack
swift
Domain
developer experience
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Swift language basicsUnderstanding of CaseIterable protocolFamiliarity with Swift compiler internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
The issue proposes investigating more efficient collections than Array for CaseIterable synthesis. Start by examining the current implementation in the Swift compiler, likely in the 'lib/Sema/' directory. Look for the synthesis logic for CaseIterable and understand how the collection of all cases is currently generated. Compare the performance characteristics of Array, Set, and other potential data structures. Consider any constraints from the Swift standard library and language design. The goal is to propose a concrete alternative that improves performance without breaking existing code.