docs(defmulti): update readme, add graphviz example

packages/defmulti/README.md

@@ -22,6 +22,7 @@ This project is part of the
 - [Usage examples](#usage-examples)
     - [Dynamic dispatch: Simple S-expression interpreter](#dynamic-dispatch--simple-s-expression-interpreter)
     - [True multiple arg dispatch](#true-multiple-arg-dispatch)
+    - [Dispatch value graph visualization](#dispatch-value-graph-visualization)
 - [Authors](#authors)
 - [License](#license)
 
@@ -53,7 +54,7 @@ yarn add @thi.ng/defmulti
 <script src="https://unpkg.com/@thi.ng/defmulti/lib/index.umd.js" crossorigin></script>
 ```
 
-Package sizes (gzipped, pre-treeshake): ESM: 750 bytes / CJS: 811 bytes / UMD: 885 bytes
+Package sizes (gzipped, pre-treeshake): ESM: 799 bytes / CJS: 862 bytes / UMD: 936 bytes
 
 ## Dependencies
 
@@ -106,6 +107,7 @@ function, but also exposes the following operations:
 - `.rels()` - return all dispatch value relationships
 - `.parents(id)` - direct parents of dispatch value `id`
 - `.ancestors(id)` - transitive parents of dispatch value `id`
+- `.dependencies()` - returns iterator of all dispatch value relationship pairs
 
 #### Dispatch value hierarchies
 
@@ -327,6 +329,46 @@ apr({type: "isa", balance: 10000});
 // Error: invalid account type: isa
 ```
 
+#### Dispatch value graph visualization
+
+To facilitate better introspection of dynamically constructed/added `defmulti()`
+implementations (with possibly deep hierarchies of dispatch values), we can
+utilize the `.dependencies()` method to extract all dispatch value relationships
+and use these to build [dependency
+graph](https://github.com/thi-ng/umbrella/tree/develop/packages/dgraph), which
+then can also be visualized.
+
+```ts
+import { defDGraph } from "@thi.ng/dgraph";
+import { toDot } from "@thi.ng/dgraph-dot";
+
+const fn = defmulti((x) => x);
+
+// dummy impls
+fn.add("a", () => {});
+fn.add("d", () => {});
+
+// dispatch value relationships
+fn.isa("b", "a");
+fn.isa("c", "b");
+fn.isa("e", "d");
+
+// build dependency graph and export as Graphviz DOT format
+console.log(toDot(defDGraph(fn.dependencies()), { id: (id) => id }));
+// digraph g {
+// "b"[label="b"];
+// "c"[label="c"];
+// "e"[label="e"];
+// "a"[label="a"];
+// "d"[label="d"];
+// "b" -> "a";
+// "c" -> "b";
+// "e" -> "d";
+// }
+```
+
+![Graphviz output](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/defmulti/readme.dot.svg)
+
 ## Authors
 
 Karsten Schmidt

packages/defmulti/tpl.readme.md

@@ -70,6 +70,7 @@ function, but also exposes the following operations:
 - `.rels()` - return all dispatch value relationships
 - `.parents(id)` - direct parents of dispatch value `id`
 - `.ancestors(id)` - transitive parents of dispatch value `id`
+- `.dependencies()` - returns iterator of all dispatch value relationship pairs
 
 #### Dispatch value hierarchies
 
@@ -292,6 +293,46 @@ apr({type: "isa", balance: 10000});
 // Error: invalid account type: isa
 ```
 
+#### Dispatch value graph visualization
+
+To facilitate better introspection of dynamically constructed/added `defmulti()`
+implementations (with possibly deep hierarchies of dispatch values), we can
+utilize the `.dependencies()` method to extract all dispatch value relationships
+and use these to build [dependency
+graph](https://github.com/thi-ng/umbrella/tree/develop/packages/dgraph), which
+then can also be visualized.
+
+```ts
+import { defDGraph } from "@thi.ng/dgraph";
+import { toDot } from "@thi.ng/dgraph-dot";
+
+const fn = defmulti((x) => x);
+
+// dummy impls
+fn.add("a", () => {});
+fn.add("d", () => {});
+
+// dispatch value relationships
+fn.isa("b", "a");
+fn.isa("c", "b");
+fn.isa("e", "d");
+
+// build dependency graph and export as Graphviz DOT format
+console.log(toDot(defDGraph(fn.dependencies()), { id: (id) => id }));
+// digraph g {
+// "b"[label="b"];
+// "c"[label="c"];
+// "e"[label="e"];
+// "a"[label="a"];
+// "d"[label="d"];
+// "b" -> "a";
+// "c" -> "b";
+// "e" -> "d";
+// }
+```
+
+![Graphviz output](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/defmulti/readme.dot.svg)
+
 ## Authors
 
 ${authors}