Swift structure skills cover the fundamental building blocks of the language: collections, optionals, control flow, closures, and other essential language features.

Available References

Collections

[Array](./references/collections_array.md) - Ordered collections, map/filter/reduce operations
[Dictionary](./references/collections_dictionary.md) - Key-value pairs, lookups, transformations
[Set](./references/collections_set.md) - Unique elements, set algebra operations

Language Features

[Optionals](./references/optionals.md) - Optional binding, unwrapping, nil handling
[Closures](./references/closures.md) - Closure expressions, trailing closure syntax
[Generics](./references/generics.md) - Generic types, constraints, associated types
[Extensions](./references/extensions.md) - Type extensions, computed properties
[Control Flow](./references/control_flow.md) - Conditionals, loops, pattern matching
[Error Handling](./references/error_handling.md) - Throws, do-catch, Result type

Data Types

[Strings](./references/strings.md) - String manipulation, interpolation, Unicode

Quick Reference

Collections Comparison

Collection	Order	Duplicates	Use When
Array	Ordered	Allowed	Indexed access needed
Dictionary	Unordered	Keys unique	Key-based lookup
Set	Unordered	Not allowed	Uniqueness required

Optional Handling

// Optional binding
if let value = optional { }
guard let value = optional else { return }

// Nil coalescing
let value = optional ?? defaultValue

// Optional chaining
let result = object?.property?.method()

Common Higher-Order Functions

array.map { $0 * 2 }           // Transform
array.filter { $0 > 0 }         // Select
array.reduce(0, +)              // Combine
array.compactMap { Int($0) }    // Transform + remove nil
array.flatMap { $0 }            // Flatten

Best Practices

Use appropriate collection - Match collection to use case
Handle optionals safely - Never force unwrap without certainty
Leverage higher-order functions - Cleaner functional code
Use extensions for organization - Group related functionality
Prefer generics for reusability - Type-safe flexible code
Make switch exhaustive - Handle all cases
Use do-catch properly - Handle errors appropriately

For More Information

Each reference file contains detailed information, code examples, and best practices for specific topics. Visit https://swiftzilla.dev for comprehensive Swift documentation.

npx skills add swiftzilla/skills --skill swift_structure