inamiy
April 15, 2026, 9:27am
1
Hello Swift Community!
I gave a talk about Swift Concurrency Type System at try! Swift Tokyo 2026 Conference.
Slide and resource materials are included in:
Formal typing rules and presentation materials for Swift 6.2's concurrency type system, focusing on Capability and Region. Presented at try! Swift Tokyo 2026.
Slide:
Video:
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# Swift Concurrency as Capability + Region Type System (English)
This document systematically summarizes the typing rules for Swift 6.2 Concurrency.
> Important: For the ground truth of function type conversions involving isolation (sync/async), always refer to:
> - `swift/Sources/concurrency-type-check/FuncConversionRules.swift`
> - `docs/diagrams/func-conversion-rules.mmd`
## Table of Contents
<!-- START ToC -->
- [1. Judgment Forms (Judgment)](#1-judgment-forms-judgment)
- [1.1 Connection to Swift (function/task body)](#11-connection-to-swift-functiontask-body)
- [2. Symbols and Auxiliary Definitions (Definitions)](#2-symbols-and-auxiliary-definitions-definitions)
- [2.1 Capability (`@κ`) and Function Type Annotation (`@φ`)](#21-capability-κ-and-function-type-annotation-φ)
- [Capability (`@κ`)](#capability-κ)
- [Function Type Annotation (`@φ = @σ @ι`)](#function-type-annotation-φ--σ-ι)
- [Conversion from `@ι` to capability `@κ` (`toCapability`)](#conversion-from-ι-to-capability-κ-tocapability)
- [Actor Isolation predicate (`isActorIsolated`)](#actor-isolation-predicate-isactorisolated)
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Though this formalization is unofficial and experimental with AI-assistance, beginner guide and PoC code are also included, so they might be helpful for further understandings.
Pls feel free to let me know your thoughts on this!
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