swiftlang/swift

Code completion: Stop suggesting old-style protocol metatype syntax in Swift 6 mode

Open

#65,699 opened on May 5, 2023

View on GitHub
 (9 comments) (0 reactions) (1 assignee)Swift (10,719 forks)batch import
bugcode completionexistentialsgood first issuemetatypessource toolingswift 5.9typesunexpected behavior

Repository metrics

Stars
 (69,989 stars)
PR merge metrics
 (Avg merge 8d 17h) (510 merged PRs in 30d)

Description

In Swift 6 mode, [.]Protocol1 is no longer a valid suggestion. Per SE-0335, we should suggest two distinct [.]Type1 completions for a plain protocol/composition — one aiming at any P.Type and another aiming at (any P).Type — that also insert a missing any prefix, and parenthesize the acted-upon existential in the second case.

Test case (should not succeed):

// RUN: %empty-directory(%t)
// RUN: %target-swift-ide-test -batch-code-completion -source-filename %s -filecheck %raw-FileCheck -completion-output-dir %t -swift-version 6

protocol P {}

let _: P#^COMPLETE1?check=META^#
let _: any P#^COMPLETE2?check=META^#
let _: (any P)#^COMPLETE3?check=META^#

// META: Keyword/None: .Protocol[#(any P).Type#]; name=Protocol

Environment

  • Swift 5.9-dev (c1d5118c21d)

Footnotes

  1. [x] means x is optional ↩ ↩2

Contributor guide

Research direction
Examine the code completion logic in the Swift compiler for protocol metatypes in Swift 6 mode, focusing on how SE 0335 changes affect the suggestions for `.Protocol` and `.Type`.
Tech stack
swift
Domain
developer experiencetooling
Issue type
Bug
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.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Swift
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60