Apple has open-sourced the Swift syntax parser, and the compiler is migrating to a pure-swift frontend. The package manager is open-source. So there's plenty of opportunity for an open-source IDE -- built on swift. And the free Visual Studio Code support based on the Swift language is good enough for most features.<p>There's little hope that IntelliJ could extend their own tooling to Swift's evolving language. Indeed, Swift has compile-time-checked regular expressions, concretely-typed generics, and so much more not seen in other languages.<p>Swift is catching up to Rust's memory/ownership model and building out both C and C++ interoperation, making them a powerful solution for safe systems programming.<p>Refactorings across a class hierarchy don't help Swift much since value types are preferred.<p>What's really missing from XCode or Swift-LS is partial parsing: effective feedback when your code is incomplete or broken, and good feedback about the mini-build that parses the Package.swift declaration.