Pros of swift

• Contains the actual Swift compiler and standard library implementation
• Allows direct contributions to the Swift language codebase
• Provides a comprehensive test suite for Swift language features

Cons of swift

• Larger and more complex codebase, potentially harder for newcomers to navigate
• Requires more technical expertise to contribute effectively
• Changes need to go through a more rigorous review process

Code comparison

swift:

public struct String {
    @usableFromInline
    internal var _guts: _StringGuts

    public init() {
        self._guts = _StringGuts()
    }
}

swift-evolution:

# String Improvements

* Proposal: [SE-0163](0163-string-revision-1.md)
* Authors: [Ben Cohen](https://github.com/airspeedswift), [Dave Abrahams](https://github.com/dabrahams)
* Review Manager: [John McCall](https://github.com/rjmccall)
* Status: **Implemented (Swift 4.0)**
* Implementation: [apple/swift#8719](https://github.com/apple/swift/pull/8719)

The swift repository contains the actual implementation of the String struct, while swift-evolution contains proposals and discussions about language improvements, such as the String revision proposal shown above.

Pros of swift-package-manager

• Focused on package management and dependency resolution
• Provides practical tools for Swift developers to manage projects
• Actively maintained with frequent updates and bug fixes

Cons of swift-package-manager

• Narrower scope compared to the broader language evolution discussions
• Less community involvement in decision-making processes
• More technical and implementation-focused, potentially less accessible to non-developers

Code comparison

swift-package-manager:

import PackageDescription

let package = Package(
    name: "MyPackage",
    dependencies: [
        .package(url: "https://github.com/example/example-package.git", from: "1.0.0"),
    ]
)

swift-evolution:

struct SE0001_AllowTrailingClosures: SwiftEvolutionProposal {
    static let id = 1
    static let status = .implemented(version: "3.0")
    static let title = "Allow (most) keywords as argument labels"
}

The swift-package-manager code demonstrates package configuration, while swift-evolution showcases proposal metadata structures.

Pros of swift-syntax

• Focuses specifically on Swift syntax parsing and manipulation
• Provides a more targeted and specialized toolset for syntax-related tasks
• Offers a comprehensive API for working with Swift source code programmatically

Cons of swift-syntax

• Narrower scope compared to swift-evolution's broader focus on language evolution
• May require more technical expertise to utilize effectively
• Less community involvement in discussions and proposals

Code Comparison

swift-syntax:

import SwiftSyntax

let sourceFile = try SyntaxParser.parse(source: "let x = 5")
let variable = sourceFile.statements.first?.item.as(VariableDeclSyntax.self)
print(variable?.bindings.first?.pattern)

swift-evolution:

// No direct code comparison available as swift-evolution
// is primarily focused on language proposals and discussions
// rather than providing a code-level API

Summary

Swift-syntax is a specialized tool for working with Swift syntax, offering powerful APIs for parsing and manipulating Swift code. Swift-evolution, on the other hand, serves as a platform for discussing and proposing changes to the Swift language itself. While swift-syntax provides more direct code-level functionality, swift-evolution offers a broader perspective on the language's development and future direction.

Pros of swift-argument-parser

• Focused on command-line argument parsing, providing a more specialized and user-friendly solution
• Offers a declarative approach to defining command-line interfaces, simplifying implementation
• Includes built-in support for generating help text and error messages

Cons of swift-argument-parser

• Limited scope compared to swift-evolution, which covers broader language changes
• May require additional dependencies for more complex command-line applications
• Less community involvement in the development process

Code Comparison

swift-argument-parser:

struct Example: ParsableCommand {
    @Argument(help: "The name to greet")
    var name: String

    func run() throws {
        print("Hello, \(name)!")
    }
}

swift-evolution:

struct Example {
    let name: String
    
    init(name: String) {
        self.name = name
    }
    
    func greet() {
        print("Hello, \(name)!")
    }
}

The swift-argument-parser example demonstrates its declarative approach to defining command-line interfaces, while the swift-evolution example shows a more traditional Swift structure without specific command-line parsing features.

Pros of swift-nio

• Focused on high-performance networking and I/O operations
• Provides a robust foundation for building server-side Swift applications
• Actively maintained and regularly updated by Apple

Cons of swift-nio

• More complex and specialized compared to swift-evolution
• Steeper learning curve for developers new to networking concepts
• Limited scope, primarily focused on networking rather than language evolution

Code Comparison

swift-nio example:

let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
let bootstrap = ServerBootstrap(group: group)
    .serverChannelOption(ChannelOptions.backlog, value: 256)
    .childChannelInitializer { channel in
        channel.pipeline.addHandler(EchoHandler())
    }

swift-evolution example:

struct MyProposal: Proposal {
    static let title = "Add a new feature to Swift"
    static let status = .awaitingReview
    static let proposal = SE0999()
    static let authors = ["John Doe"]
}

Summary

While swift-evolution focuses on the Swift language's development process and proposals, swift-nio is a specialized networking framework. swift-nio offers powerful tools for building high-performance networking applications but has a narrower scope compared to swift-evolution's broader impact on the Swift language itself.

Pros of Rust

• More mature and established project with a larger community
• Focuses on the entire language implementation, not just proposals
• Offers a more comprehensive view of the language's development

Cons of Rust

• Larger codebase, potentially more challenging for newcomers to navigate
• Less focused on language evolution proposals compared to Swift Evolution
• May require more time to understand the project structure and contribute

Code Comparison

Swift Evolution (proposal example):

public struct SE0001_AllowTrailingClosures {
    public static let proposal = Proposal(
        number: 1,
        status: .implemented(version: "3.0"),
        title: "Allow (most) keywords as argument labels",
        description: """
        Swift should allow the use of all keywords except `inout`, `var`, and `let` as argument labels.
        """
    )
}

Rust (language feature implementation):

pub fn allow_keywords_as_identifiers(input: &str) -> bool {
    match input {
        "inout" | "var" | "let" => false,
        _ => true
    }
}

The Swift Evolution repository focuses on language proposals, while the Rust repository contains the actual implementation of language features. Swift Evolution's code is more structured around proposal documentation, whereas Rust's code directly implements language functionality.