Effect 3.18 has been released! This release includes a number of new features and improvements. Here’s a summary of what’s new:
Graph module
An experimental Graph module has been added, with comprehensive graph data structure support.
The Graph module provides:
- Directed and undirected graph support
- Immutable and mutable graph variants
- Type-safe node and edge operations
- Graph algorithms: DFS, BFS, shortest paths, cycle detection, etc.
import { Graph } from "effect"
// Create a graph with mutationsconst graph = Graph.directed<string, number>((mutable) => { const nodeA = Graph.addNode(mutable, "Node A") const nodeB = Graph.addNode(mutable, "Node B") Graph.addEdge(mutable, nodeA, nodeB, 5)})
console.log( `Nodes: ${Graph.nodeCount(graph)}, Edges: ${Graph.edgeCount(graph)}`,)Context.ReadonlyTag
The ReadonlyTag type is the covariant side of a Context.Tag, that can be used to constrain tags that match a certain service shape.
import type { Context } from "effect"import { Effect } from "effect"
export class MyRequirement extends Effect.Service<MyRequirement>()( "MyRequirement", { succeed: () => 42, },) {}
export class MyUseCase extends Effect.Service<MyUseCase>()("MyUseCase", { dependencies: [MyRequirement.Default], effect: Effect.gen(function* () { const requirement = yield* MyRequirement return Effect.fn("MyUseCase.execute")(function* () { return requirement() }) }),}) {}
export function effectHandler<I, Args extends Array<any>, A, E, R>( service: Context.ReadonlyTag<I, (...args: Args) => Effect.Effect<A, E, R>>,) { return Effect.fn("effectHandler")(function* (...args: Args) { const execute = yield* service yield* execute(...args) })}
export const program = effectHandler(MyUseCase)Other changes
resizemethod has been added toEffect.Semaphore, allowing dynamic adjustment of a semaphore’s permits.
There were several other smaller changes made. Take a look through the CHANGELOG to see them all: CHANGELOG.
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