swift1013 B

Swift — Task list (struct, protocol, optionals)

A realistic Swift snippet with an enum, a protocol, a struct with a computed property, optionals and optional binding, and higher-order functions — for testing highlighters, the Swift compiler, SwiftLint, and parsers.

Syntax highlighting Code parsing Editor testing

Preview — first 47 linesswift

// A small task model in Swift: an enum, a protocol, a struct with a
// computed property, optionals, and higher-order functions.
import Foundation

enum Priority: Int, CaseIterable {
    case low = 1, normal, high
}

protocol Summarizable {
    var summary: String { get }
}

struct Task: Summarizable {
    let title: String
    var priority: Priority = .normal
    var done: Bool = false

    var summary: String {
        let box = done ? "[x]" : "[ ]"
        return "\(box) \(title) (priority \(priority.rawValue))"
    }
}

struct TaskList {
    private(set) var tasks: [Task] = []

    mutating func add(_ task: Task) {
        tasks.append(task)
    }

    func next() -> Task? {
        tasks.filter { !$0.done }.max { $0.priority.rawValue < $1.priority.rawValue }
    }
}

var list = TaskList()
list.add(Task(title: "Write tests", priority: .high))
list.add(Task(title: "Ship release"))

for task in list.tasks {
    print(task.summary)
}

if let up = list.next() {
    print("next up: \(up.title)")
}

Specifications

Language: Swift
Kind: realistic snippet
Lines: 46
Encoding: UTF-8
Line Endings: LF

Testing contract

Expected to pass

Scenario: Compile the file and exercise the optional-returning members it declares.
Expected result: It compiles with no warnings and no force-unwraps: the struct's computed property, the protocol conformance and the higher-order functions all type-check, and the optional binding path is taken when a lookup misses rather than trapping.

What is a .swift file?

Swift (.swift) is a plain-text source file for the Swift programming language — a statically typed, compiled language from Apple used for iOS, macOS, and server development. It emphasises safety with optionals and value types, and features structs, protocols, generics, and pattern matching.

How to use this file

Use an example .swift file to test syntax highlighters, the Swift compiler, linters and formatters (SwiftLint, swift-format), and parser or language-detection tooling.

How to use this file for testing

“Swift — Task list (struct, protocol, optionals)” is a deterministic Novus Examples fixture for Syntax highlighting, Code parsing, Editor testing. Idiomatic hello-world programs and realistic snippets across sixteen languages, exercising comments, string escapes, interpolation, numeric literals, and language keywords — for testing syntax highlighters, editor themes, and tree-sitter grammars.

Documented properties for this file: Swift · UTF-8 · LF. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.

Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.

This is a short, known-correct source file. Run it through your syntax highlighter, linter, formatter, tree-sitter grammar, or parser, and open it in the in-browser editor to tweak and re-download. Each snippet exercises comments, string escapes, literals, and language keywords.

Code examples

swift task-list.swift

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