feat(adjacency) hasVertex

packages/adjacency/src/api.ts

@@ -41,6 +41,12 @@ export interface IGraph<T = number> {
 	 * @param to -
 	 */
 	hasEdge(from: T, to: T): boolean;
+	/**
+	 * Returns true if a vertex exists for the given id.
+	 *
+	 * @param id -
+	 */
+	hasVertex(id: T): boolean;
 	/**
 	 * Returns number of edges for given vertex. By default only outgoing edges
 	 * are counted, but can be customized via given {@link DegreeType}. Note: In

packages/adjacency/src/binary.ts

@@ -71,6 +71,10 @@ export class AdjacencyBitMatrix implements IGraph<number> {
 		return this.mat.at(from, to) !== 0;
 	}
 
+	hasVertex(id: number): boolean {
+		return this.mat.popCountRow(id) !== 0 || this.mat.popCountColumn(id) !== 0;
+	}
+
 	degree(id: number, type: DegreeType = "out") {
 		let degree = 0;
 		if (this.undirected || type !== "in")

packages/adjacency/src/list.ts

@@ -60,6 +60,10 @@ export class AdjacencyList implements IGraph<number> {
 		return true;
 	}
 
+	hasVertex(id: number) {
+		return !!this.adjacency[id];
+	}
+
 	addEdge(from: number, to: number) {
 		const vertex = this.ensureVertexData(from);
 		this.ensureVertexData(to);

packages/adjacency/src/sparse.ts

@@ -53,6 +53,10 @@ export class AdjacencyMatrix extends CSR implements IGraph<number> {
 		return this.at(from, to) !== 0;
 	}
 
+	hasVertex(id: number): boolean {
+		return this.degree(id, "inout") > 0;
+	}
+
 	numEdges() {
 		const n = this.data.length;
 		return this.undirected ? n / 2 : n;

packages/adjacency/test/binary.ts

@@ -68,4 +68,16 @@ group("adjacency (bitmatrix)", {
 			"edges"
 		);
 	},
+	hasVertex: () => {
+		const m = defAdjBitMatrix(6, [
+			[0, 1],
+			[5, 4],
+		] satisfies typeof edges, true);
+		assert.ok(m.hasVertex(0));
+		assert.ok(m.hasVertex(1));
+		assert.ok(!m.hasVertex(2));
+		assert.ok(!m.hasVertex(3));
+		assert.ok(m.hasVertex(4));
+		assert.ok(m.hasVertex(5));
+	}
 });

packages/adjacency/test/list.ts

@@ -24,4 +24,14 @@ group("adjacency (list)", {
 		);
 		// console.log(m.toString());
 	},
+	hasVertex: () => {
+		const m = defAdjList([
+			[1, 2],
+			[2, 0],
+		]);
+		assert.ok(m.hasVertex(0));
+		assert.ok(m.hasVertex(1));
+		assert.ok(m.hasVertex(2));
+		assert.ok(!m.hasVertex(3));
+	}
 });

packages/adjacency/test/sparse.ts

@@ -37,4 +37,16 @@ group("adjacency (sparse)", {
 			"edges"
 		);
 	},
+	hasVertex: () => {
+		const m = defAdjMatrix(6, [
+			[0, 1],
+			[5, 4],
+		] satisfies typeof edges, true);
+		assert.ok(m.hasVertex(0));
+		assert.ok(m.hasVertex(5));
+		assert.ok(m.hasVertex(1));
+		assert.ok(m.hasVertex(4));
+		assert.ok(!m.hasVertex(2));
+		assert.ok(!m.hasVertex(3));
+	}
 });

packages/bitfield/test/index.ts

@@ -1,5 +1,18 @@
 import { group } from "@thi.ng/testament";
-// import * as assert from "assert";
-// import * as b from "../src/index.js"
+import * as assert from "assert";
+import { BitField } from "../src/index.js"
 
-group("bitfield", {});
+group("bitfield", {
+	'setAt (boolean)': () => {
+		const bf = new BitField(8);
+		assert.ok(!bf.at(1));
+		bf.setAt(1, true);
+		assert.ok(!!bf.at(1));
+	},
+	'setAt (number)': () => {
+		const bf = new BitField(8);
+		assert.ok(!bf.at(1));
+		bf.setAt(1, 4);
+		assert.ok(!!bf.at(1));
+	}
+});