SafeTypes is a Swift package that delivers a suite of constrained wrappers for common data structures and primitives, enforcing specific conditions and providing functionality to operate safely within those bounds.
If you are targetting Swift 5.9+ I highly suggest you install SafeTypesMacros alongside it. It adds macros for non optional initializers from literals (compilation-time check for literal values. Eg: #Positive(1) evaluates to Postive(1) instead of Optional<Postive(1)>, and #Positive(-1) would fail to compile).
By ensuring conditions at compile time, SafeTypes allows developers to write safer, more robust and expressive code with reduced boilerplate, increased performance, and improved documentation through its constrained types.
ℹ️ Note: Most constructors from these custom types will be optional so any client needs to construct and deal with the unhappy path at construction.
For compile time check validation (and non optional initializers) for literals (only literals, not dynamic values) SafeTypesMacros adds special macros for it! I definitely recommend you check it out!
- Type-safe containers that prevent invalid states
- Enforced type constraints and operations
- Enhanced code readability and maintainability
- Simplified method interfaces and APIs
- Streamlined unit testing by eliminating redundant unhappy-path checks
Add the following to your Package.swift file's dependencies:
.package(url: "https://github.com/lucaswkuipers/SafeTypes.git", from: "1.0.0")Or simply Select File > Add Package Dependencies, and enter the following URL:
https://github.com/lucaswkuipers/SafeTypes.git
And then, wherever needed:
import SafeTypesBelow are some of the types provided by SafeTypes and brief examples of their usage:
An array that is guaranteed to have more than one element.
// ✅ Non Optional Initializers
MultiElementsArray(1, 2) // MultiElementsArray<Int>
MultiElementsArray(1.0, 2.0, 3.0) // MultiElementsArray<Double>
MultiElementsArray(false, true, true, false) // MultiElementsArray<Bool>
// ❓ Optional Initializers
MultiElementsArray(["Alice", "Bob"]) // Optional<MultiElementsArray<String>>
MultiElementsArray(repeating: 1, count: 2) // Optional<MultiElementsArray<Int>>
// ❌ Fails to compile
MultiElementsArray(1) // Doesn't compile, missing argument
MultiElementsArray() // Doesn't compile, missing argumentsAn array that is guaranteed to have at least one element.
// ✅ Non Optional Initializers
NonEmptyArray(1) // NonEmptyArray<Int>
NonEmptyArray(1.0, 2.0) // NonEmptyArray<Double>
NonEmptyArray(false, true, true) // NonEmptyArray<Bool>
// ❓ Optional Initializers
NonEmptyArray(["Alice", "Bob"]) // Optional<NonEmptyArray<String>>
NonEmptyArray(repeating: 1, count: 1) // Optional<NonEmptyArray<Int>>
// ❌ Fails to compile
NonEmptyArray() // Doesn't compile, missing argumentsA string that's guaranteed to contain at least one character (can be empty character).
// ❓ Optional Initializers
NonEmptyString(["Alice", "Bob"]) // Optional<NonEmptyString>
NonEmptyString(repeating: 1, count: "h") // Optional<NonEmptyString>
// ❌ Fails to compile
NonEmptyString() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#NonEmptyStringand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
A number that is guaranteed to be greater than zero (value > 0)
// ❓ Optional Initializers
Positive(123) // Optional<Positive<Int>>
Positive(42.69) // Optional<Positive<Double>>
// ❌ Fails to compile
Positive() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#Positiveand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
A number that is guaranteed to be less than zero (value < 0)
// ❓ Optional Initializers
Negative(-123) // Optional<Negative<Int>>
Negative(-42.69) // Optional<Negative<Double>>
// ❌ Fails to compile
Negative() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#Negativeand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
A number that is guaranteed to be less than or equal to zero (value <= 0)
// ❓ Optional Initializers
NonPositive(-123) // Optional<NonPositive<Int>>
NonPositive(-42.69) // Optional<NonPositive<Double>>
NonPositive(0) // Optional<NonPositive<Int>>
NonPositive(0.0) // Optional<NonPositive<Double>>
// ❌ Fails to compile
NonPositive() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#NonPositiveand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
A number that is guaranteed to be greater than or equal to zero (value >= 0)
// ❓ Optional Initializers
NonNegative(123) // Optional<NonNegative<Int>>
NonNegative(42.69) // Optional<NonNegative<Double>>
NonNegative(0) // Optional<NonNegative<Int>>
NonNegative(0.0) // Optional<NonNegative<Double>>
// ❌ Fails to compile
NonNegative() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#NonNegativeand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
A number that is guaranteed to be different than zero (value != 0)
// ❓ Optional Initializers
NonZero(123) // Optional<NonZero<Int>>
NonZero(42.69) // Optional<NonZero<Double>>
NonZero(-123) // Optional<NonZero<Int>>
NonZero(-42.69) // Optional<NonZero<Double>>
// ❌ Fails to compile
NonZero() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#NonZeroand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
Represents a value that's within the range of -1 to 1, inclusive.
// ❓ Optional Initializers
MinusOneToOne(-1) // Optional<MinusOneToOne<Int>>
MinusOneToOne(-1.0) // Optional<MinusOneToOne<Double>>
MinusOneToOne(-0.314159) // Optional<MinusOneToOne<Double>>
MinusOneToOne(0) // Optional<MinusOneToOne<Int>>
MinusOneToOne(0.0) // Optional<MinusOneToOne<Double>>
MinusOneToOne(0.1234) // Optional<MinusOneToOne<Double>>
MinusOneToOne(1) // Optional<MinusOneToOne<Double>>
// ❌ Fails to compile
#MinusOneToOne(-1.1) // Doesn't compile, macro argument can't be less than -1
#MinusOneToOne(42.1) // Doesn't compile, macro argument can't be greater than 1
#MinusOneToOne() // Doesn't compile, missing macro argument
MinusOneToOne() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#MinusOneToOneand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
Represents a value from 0 to 1, inclusive.
// ❓ Optional Initializers
ZeroToOne(0) // Optional<ZeroToOne<Int>>
ZeroToOne(0.0) // Optional<ZeroToOne<Double>>
ZeroToOne(0.1234) // Optional<ZeroToOne<Double>>
ZeroToOne(1) // Optional<ZeroToOne<Double>>
// ❌ Fails to compile
ZeroToOne() // Doesn't compile, missing initializer argument
⚠️ Attention: To use#ZeroToOneand other helpful macros, make sure to install the addon macros SwiftTypesMacros (Swift 5.9+)
Each type guarantees compliance with its stated constraints so that your functions and methods can rely on those qualities and pass them on (not losing information).
SafeTypes is awesome and SafeTypesMacros makes it even more so by enabling you to construct the types from SafeTypes from literals and have them be evaluated (as valid or not) at compile time. Check it out.
Contributions are what make the open-source community such a fantastic place to learn, inspire, and create. Any contributions you make are greatly appreciated.
If you want to start contributing but don't know what to work on, try looking at the open Issues Tab
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Fork the Project
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Create your Branch (
git checkout -b feature/AmazingFeature) -
Commit your Changes (
git commit -m 'Add some AmazingFeature') -
Push to the Branch (
git push origin feature/AmazingFeature) -
Open a Pull Request
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Oh and don't forget to add or update tests when applicable! :D
Thank you so much for contributing <3
Distributed under the MIT License. See LICENSE for more information.
Feel free to reach out to me:
SafeTypes can be found at Swift Package Index
Some of the relevant sources of inspiration:
Thank you so much for considering SafeTypes for your next Swift project – I hope you find it as enjoyable to use as I found it to write!
