This is a lightweight, fast and easy to use directed acyclic graph (DAG) implementation in Swift.
It is developed and maintained as part of the Fireblade Game Engine project.

These instructions will get you a copy of the project up and running on your local machine and provide a code example.

• Swift Package Manager (SPM)
• Swiftlint for linting - (optional)
• SwiftEnv for Swift version management - (optional)

Fireblade Graph is available for all platforms that support Swift 5 and higher and the Swift Package Manager (SPM).

Extend the following lines in your Package.swift file or use it to create a new project.

// swift-tools-version:5.2

import PackageDescription

let package = Package(
    name: "YourPackageName",
    dependencies: [
    .package(url: "https://github.com/fireblade-engine/graph.git", from: "1.3.0")
    ],
    targets: [
        .target(
            name: "YourTargetName",
            dependencies: ["FirebladeGraph"])
    ]
)

The Node is the core element of the package.
It is representing a node in a directed acyclic graph (DAG) and holds a (weak) reference to its parent node and references to its child nodes.

To create a graph create a node and add children.

let rootNode = Node<Void>()

let child1 = Node<Void>()
let child2 = Node<Void>()

rootNode.addChild(child1)
rootNode.addChild(child2)

A DAG implementation starts to shine when you can add functionality or behavior to its nodes.
This is acchieved by subclassing Node and implementing the desired behavior in its .updateFromParent() method as well as setting the node's generic Content constraint.

class StringNode: Node<String> {

	let content: String
	
	func myFunc() { ... } // or functions

    override open func updateFromParent() {
        super.updateFromParent()
    
        // ... and do fancy stuff here ...
    }
}

let node = StringNode("Hello World!")

To traverse through the graph from root to leave nodes call .update() on the root node of the graph.

let rootNode = Node<Void>()

// ... build up your graph here ...

rootNode.update()

We use SemVer for versioning. For the versions available, see the tags on this repository.

• Christian Treffs

See also the list of contributors who participated in this project.

This project is licensed under the MIT License - see the LICENSE file for details