https://github.com/capnslipp/with

with(…) { … } Statement (a Swift µ-Library)
https://github.com/capnslipp/with

context operator operators scope swift swift-library utilities utility

Last synced: 3 months ago
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with(…) { … } Statement (a Swift µ-Library)

• Host: GitHub
• URL: https://github.com/capnslipp/with
• Owner: capnslipp
• License: unlicense
• Created: 2020-03-06T15:34:41.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2024-09-11T19:20:43.000Z (5 months ago)
• Last Synced: 2024-10-13T10:06:41.917Z (4 months ago)
• Topics: context, operator, operators, scope, swift, swift-library, utilities, utility
• Language: Swift
• Homepage:
• Size: 51.8 KB
• Stars: 10
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# With

With is a Swift micro-library that provides a `with` statement— _which is modeled after the `with` functionality found in Python, JavaScript, Visual Basic, Object Pascal, Delphi; `using` found in C#; and `also`/`let` found in Kotlin._

With provides a set of overloaded generic free functions that are useful for:

* Object or value initialization and setup in a declarative style _(think Swift UI's hierarchical style, but for anything, anywhere)_.

* Performing multiple operations on an object/value fetched via a method/property, while staying D.R.Y and without needing to create a local var _(while still avoiding invoking the method/getter repeatedly)_.

* Performing calculations with an object/value that only needs to live long enough to be configured and do some calc _(and you're only interested in a result object/value)_.

With provides a free function `func with(_ subject: SubjectT, operations: (inout SubjectT) -> Void) -> SubjectT` that can be used on any object or value type to do stuff like this:

```swift

// initializes a value-type `hitTestOptions` dictionary  for use with

//   `SCNView`'s `hitTest(…)` with the desired options some of which have

//   changed in newer OS versions (which the standard dictionary literal syntax

//   can't cleanly do)

let hitTestOptions = with([SCNHitTestOption : Any]()) {

	$0[.boundingBoxOnly] = true

	$0[.rootNode] = _myRootNode

	if #available(iOS 11.0, tvOS 11.0, macOS 10.13, *) {

		$0[.searchMode] = SCNHitTestSearchMode.all.rawValue

	} else {

		$0[.sortResults] = true

		$0[.firstFoundOnly] = false

	}

}

```

Or like this:

```swift

// initializes the object-type `newButton` with title, sizing, styling, etc.

//   and adds the view to a superview

let newButton = with(UIButton(type: .system)) {

	$0.titleLabel!.font = .systemFont(ofSize: 13)

	$0.setTitle("My Button", for: .normal)

	$0.autoresizingMask = [ .flexibleLeftMargin, .flexibleBottomMargin ]

	$0.contentEdgeInsets = UIEdgeInsets(top: 6.5, left: 7, bottom: 6.5, right: 7)

	with($0.layer) { layer in

		layer.borderWidth = 1.0

		layer.borderColor = UIColor.white.cgColor

		layer.cornerRadius = 5

	}

	$0.sizeToFit()

	

	rootViewController.view.addSubview($0)

}

```

With also has an alternate `func withMap(_ subject: SubjectT, operations: (inout SubjectT) -> ReturnT) -> SubjectT` form that can return an arbitrary value from the closure (instead of the value passed in):

```swift

// initializes a `DateFormatter`, configures it, and uses it to calculate a

//   `String` which is the only thing we want to hang onto

let dateString = withMap(DateFormatter()) {

	$0.dateStyle = .medium

	$0.timeStyle = .none

	$0.locale = Locale(identifier: "en_US")

	

	let currentDate = Date()

	return $0.string(from: currentDate)

}

```