swiftlang/swift

[SR-4294] Warn about overly-nested generic type specifiers

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#46,877 opened on Mar 20, 2017

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bugcompilerdiagnostics qualitygood first issue

Description
Previous ID SR-4294
Radar None
Original Reporter @jckarter
Type Bug
Votes 0
Component/s Compiler
Labels Bug, DiagnosticsQoI, StarterBug
Assignee None
Priority Medium

md5: c1aab4167ab2d03975e533b9a662698f

Issue Description:

https://twitter.com/steipete/status/843896945718546434

The tweet is in C++, but the same problem could affect Swift. A warning about overly-nested generic type specifiers that have enough piled-up closing >>>>>> brackets to be mistaken for a conflict marker in version control might be helpful, not only for tooling interaction, but for code cleanliness, since you should probably consider using a type alias at that point.

Contributor guide

Tech stack
swift
Domain
developer experiencetooling
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.
half day
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 basicsCompiler architectureSwift generics syntax
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Investigate the Swift compiler's diagnostic system to understand how warnings are emitted for complex types. Look at the parser or type checker for handling nested generic type specifiers. Consider adding a warning when the nesting depth exceeds a certain threshold. Refer to existing warnings in the compiler for guidance.
[SR-4294] Warn about overly-nested generic type specifiers · swiftlang/swift#46877 | Good First Issue