Moximillian

@Moximillian·10 public vizzes

Journey into PAT-land

This example shows a programmer’s repeated attempts to create a unified interface for dequeuing reusable cells across UITableView and UICollectionView in Swift, using protocols with associated types and generics. The code illustrates the progression from a simple protocol that fails to preserve type information, through generic and PAT-based approaches, to a final multiprotocol solution incorporating a parent protocol and Self-typed static methods. It highlights the Swift compiler’s constraints, such as lack of parametrized extensions and existential casting limitations, while referencing ProtoKit, UITableView, UICollectionView, and IndexPath.

Nov 26, 2018

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Gist b7643abc7d460e1673981d3f41bb9b40

This example demonstrates a Swift language extension that optimizes the `reversed()` operation on lazy collections. It defines a `ReversedCollectionProtocol` for bidirectional collections, and an extension that lets reversing a lazy reversed collection return a lazy representation of the original, avoiding unnecessary materialization. The code uses Swift generics and associated types (`Elements.Base`) to express this optimization, and notes a fallback using parametrized extensions for Swift versions prior to 4.2.

Jun 11, 2018

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Gist 6ec7e2d2e5b12c1bce0d09b7faa51ee2

This example demonstrates a key-value observing (KVO) binding mechanism in Swift, where changes to a property on one NSObject subclass (Foo.bar) automatically update a property on another (Zoq.fot). The code uses the Foundation framework, specifically the `observe(_:options:changeHandler:)` method with KeyPaths, and stores a `Disposable` object via `objc_setAssociatedObject` to manage observation lifecycle. Reassigning the target object (Zoq) triggers the `Disposable` deinit, which invalidates the observation and stops further updates, as shown by the printed deinit messages and unchanged `fot` values after reassignment.

May 25, 2018

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Example of how init/func behaves in protocols and protocol extensions

This example demonstrates how Swift handles `init` and `func` declarations in protocols versus protocol extensions. It defines two similar protocol pairs—one where `P1` declares both members, and another where `P2` is empty and relies entirely on its extension—to show that a struct’s own implementations always take precedence over those in the extension. The code creates instances of `S1` and `S2` and calls their methods, printing "S1 init"/"S1 func" and "S2 init"/"S2 func" respectively, proving that the extension’s fallback implementations are never invoked when the struct provides its own.

Apr 28, 2018

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Examples how to use closures

This example shows two ways to define and call functions that accept closures in Swift. The first passes an inline closure that takes an integer and returns a string, producing a computed result. The second uses an escaping closure that returns a `UIViewController`, demonstrating how to instantiate a view controller lazily. The code relies on Swift’s closure syntax and the UIKit `UIViewController` class, with the second closure marked `@escaping` to allow storage beyond the function call.

Apr 22, 2018

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bar chart

This example shows a small, static bar chart of five categorical values, with each bar colored individually and labeled A through E. The chart displays the data using SVG rectangles, with linear and ordinal scales mapping the values to positions and heights. The code uses d3.js version 3.5, specifically d3.scale.linear and d3.scale.ordinal, along with d3.svg.axis for the x and y axes. The data is hard-coded in the script and rendered on a light grey canvas with margins applied via a group transform.

Mar 23, 2017

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bar chart

This example displays an empty SVG canvas sized at 960 by 500 pixels. It uses D3 v3’s selection and append methods to create the SVG element inside the page body. The code sets up the basic structural foundation for a bar chart but does not yet include any data or visual marks. The rendering relies on D3’s SVG manipulation capabilities, with the styling applied through a fixed full-viewport body layout. The current state shows only the blank plotting area, leaving the chart’s data and bar geometry entirely unspecified.

Mar 22, 2017

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house

A static SVG illustration of a house scene depicts a red building with a brown roof, yellow door, green ground, and a column of smoke rising from a chimney. The composition includes decorative stars, a whiskey label, and text reading “SMOKE NO FIRE.” The code applies a gooey filter effect to the smoke shapes using SVG filters and animates nothing. It is built with pure SVG markup inside an HTML file, using no JavaScript or D3 APIs, and renders entirely via inline SVG elements.

Mar 22, 2017

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Swift protocol and extensions for adding support to closures in UIKit classes. Extension support for UIButton, UIGestureRecognizer, UIBarButtonItem etc. Swift 3.0.

This example demonstrates a Swift protocol that adds closure-based event handling to UIKit classes, replacing traditional target-action patterns. Code extensions for UIButton, UIPageControl, UIGestureRecognizer, and UIBarButtonItem use the Closurable protocol to wrap callbacks in a ClosureContainer object, stored via objc_setAssociatedObject. The container exposes an @objc selector that invokes the stored closure, allowing UIKit to call the handler dynamically. The code pairs each UI component’s standard addTarget or initializer with custom convenience methods, keeping the call site concise. No external libraries are required; the implementation relies solely on Swift 3.0 and the Objective-C runtime.

Feb 4, 2017

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New valuetype for enums to convert a minimum and maximum value into Range<Int>

This example demonstrates a custom Swift enum value type that converts string literals into `Range<Int>` values, enabling pattern matching and range checks for age categories. The `StringRangeRawValue` struct conforms to `StringLiteralConvertible` and `Equatable`, parsing comma-separated strings like "0,1" into ranges. An `AgeGroup` enum uses this type for cases such as `.Infant`, `.Toddler`, and `.Child`. The code shows two use cases: a `switch` statement matching an integer age against enum values, and an `if` statement using the `~=` operator to test whether a value falls within a range.

Mar 24, 2016