Swift Logic Operators

Swift Logic Operators provides logical operators for optional Boolean values and Predicates.

Features

• Logical NOT (!) for Predicates and optional Booleans
• Logical AND (&&) for Predicates and optional Booleans
• Logical OR (||) for Predicates and optional Booleans
• Logical NAND (!&&) for optional Booleans
• Logical NOR (!||) for optional Booleans
• Logical XOR (^) for Predicates and optional Booleans
• Logical XNOR (!^) for optional Booleans
• Equality (==) and Inequality (!=) comparisons for Predicates and optional values

Usage

Logical Operators for Optional Booleans

NOT (!)

Performs a logical NOT operation on an optional Boolean value.

!true  == false
!false == true
!nil   == nil

AND (&&)

Performs a logical AND operation between two optional Boolean values.

true && false  == false
true && nil    == nil
false && nil   == nil
false && false == false
true && true   == true
nil && nil     == nil

NAND (!&&)

Performs a logical NAND operation between two optional Boolean values.

true !&& false  == true
true !&& nil    == nil
false !&& nil   == nil
false !&& false == true
true !&& true   == false
nil !&& nil     == nil

OR (||)

Performs a logical OR operation between two optional Boolean values.

true || false   == true
true || nil     == true
false || nil    == nil
false || false  == false
nil || nil      == nil

NOR (!||)

Performs a logical NOR operation between two optional Boolean values.

true !|| false  == false
true !|| nil    == nil
false !|| nil   == nil
false !|| false == true
nil !|| nil     == nil

Equality (==)

Checks for equality between two optional Boolean values.

true == false == false
true == true  == true
true == nil   == nil
nil == nil    == nil

Inequality (!=)

Checks for inequality between two optional Boolean values.

true != false == true
true != true  == false
true != nil   == nil
nil != nil    == nil

XOR (^)

Performs a logical XOR operation between two optional Boolean values.

true ^ false   == true
true ^ nil     == nil
false ^ nil    == nil
false ^ false) == false

XNOR (!^)

Performs a logical XNOR operation between two optional Boolean values.

true !^ false  == false
true !^ nil    == nil
false !^ nil   == nil
false !^ false == true

Logical Operators for Predicates

AND (&&)

Performs a logical AND operation between two Boolean-returning closures.

let isEven: (Int) -> Bool = { $0 % 2 == 0 }
let isPositive: (Int) -> Bool = { $0 > 0 }
let isEvenAndPositive = isEven && isPositive

isEvenAndPositive(4)  == true
isEvenAndPositive(-4) == false
isEvenAndPositive(3)  == false
isEvenAndPositive(-3) == false

OR (||)

Performs a logical OR operation between two Boolean-returning closures.

let isEven: (Int) -> Bool = { $0 % 2 == 0 }
let isNegative: (Int) -> Bool = { $0 < 0 }
let isEvenOrNegative = isEven || isNegative

isEvenOrNegative(4)  == true
isEvenOrNegative(-4) == true
isEvenOrNegative(3)  == false
isEvenOrNegative(-3) == true

NOT (!)

Performs a logical NOT operation on the result of a Boolean-returning closure.

let isEven: (Int) -> Bool = { $0 % 2 == 0 }
let isOdd = !isEven

isEven(4) = true
isOdd(4)  = false
isEven(5) = false
isOdd(5)  = true

EQUAL (==)

Performs a logical equality check between the results of two Boolean-returning closures.

let isEven: (Int) -> Bool = { $0 % 2 == 0 }
let isPositive: (Int) -> Bool = { $0 > 0 }
let isEvenAndPositiveEqual = isEven == isPositive

isEvenAndPositiveEqual(4)  == false
isEvenAndPositiveEqual(-4) == false
isEvenAndPositiveEqual(3)  == false
isEvenAndPositiveEqual(-3) == true

NOT EQUAL (!=)

Performs a logical inequality check between the results of two Boolean-returning closures.

let isEven: (Int) -> Bool = { $0 % 2 == 0 }
let isPositive: (Int) -> Bool = { $0 > 0 }
let isEvenAndPositiveDifferent = isEven != isPositive

isEvenAndPositiveDifferent(4)  = true
isEvenAndPositiveDifferent(-4) = true
isEvenAndPositiveDifferent(3)  = true
isEvenAndPositiveDifferent(-3) = false

XOR (^)

Performs a logical XOR (exclusive OR) operation between two Boolean-returning closures.

let isEven: (Int) -> Bool = { $0 % 2 == 0 }
let isPositive: (Int) -> Bool = { $0 > 0 }
let isEvenOrPositive = isEven ^ isPositive

isEvenOrPositive(4)  == false
isEvenOrPositive(-4) == true
isEvenOrPositive(3)  == true
isEvenOrPositive(-3) == false

Tests

This package includes comprehensive tests for all custom logical operators and functions. The tests ensure that the operators behave correctly with all possible combinations of optional Boolean values.

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

Installation

To install LogicOperators, add the following line to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/coenttb/swift-logic-operators.git", from: "0.1.0")
]

You can then make LogicOperators available to your package's target by including LogicOperators in the dependencies of any target in your package, as follows:

targets: [
    .target(
        name: "TheNameOfYourTarget",
        dependencies: [
            .product(name: "LogicOperators", package: "swift-logic-operators")
        ]
    )
]

Finally, import LogicOperators in your .swift file(s), as follows:

import LogicOperators

...your swift code...