dflow

is a minimal Dataflow programming engine

Features

• Implemented in TypeScript, available both on Node and Deno.
• Expressive API.
• Easily create nodes, just extending DflowNode class.
• Example nodes catalog with basic JavaScript features. NOTA BENE: it is supposed that you implement your own nodes, for example node addition could be implemented using bigint or some floating point library, according to your needs.
• Minimal internal type system. It is possible to connect an output of type T only to an input of type U, if and only if U includes T.
• Graphic interface implemented with WebComponents. (demo here) (to be completed).

Installation

Node

With npm do

npm install dflow

Deno

Create an import_map.json file like this.

{
  "imports": {
    "dflow/": "https://unpkg.com/dflow/"
  }
}

Then you can import for example the following.

import { DflowHost } from "dflow/dflow.ts";
import { nodesCatalog } from "dflow/nodes/index.ts";

const dflow = new DflowHost({ nodesCatalog });

With deno you can then launch your script like this

deno run --importmap=import_map.json path/to/my/script.ts

It is recommended to point to a specific version, for instance to point to version 0.36 or whatever, then change your import map accordingly

{
  "imports": {
-    "dflow/": "https://unpkg.com/dflow/"
+    "dflow/": "https://unpkg.com/[email protected]/"
  }
}

Usage

This is a trivial sample graph that will run sin(π / 2) = 1 computation.

   ----------------
  | number = π / 2 |
   ----------------
   |
   |
   ---------
  | mathSin |
   ---------
    \
     \
     ------------
    | consoleLog |
     ------------

You can run the following code with any of the following:

• launching command deno run https://raw.githubusercontent.com/fibo/dflow/main/examples/usage.js
• cloning this repo and launching node examples/usage.js.

You should see a number 1 printed on output.

import { DflowHost } from "dflow";
import { nodesCatalog } from "dflow/nodes";

function rungraph() {
  // use builtin nodes
  const dflow = new DflowHost({ nodesCatalog });
  const catalog = dflow.nodesCatalog;

  // create nodes
  const numNode = dflow.newNode({
    kind: catalog.data.kind,
    // set numNode output to π / 2
    outputs: [{ data: Math.PI / 2 }],
  });
  const sinNode = dflow.newNode({
    kind: catalog.mathSin.kind,
  });
  const consoleLogNode = dflow.newNode({
    kind: catalog.consoleLog.kind,
  });

  // connect numNode to sinNode and sinNode to consoleLog
  dflow.connect(numNode).to(sinNode);
  dflow.connect(sinNode).to(consoleLogNode);

  // run graph
  dflow.run();
}

rungraph();

License

MIT