feat(rstream-graph): add node2(), update sub/div

packages/rstream-graph/src/graph.ts

@@ -1,4 +1,4 @@
-import { IObjectOf } from "@thi.ng/api";
+import { IObjectOf, Tuple } from "@thi.ng/api";
 import { IAtom } from "@thi.ng/atom";
 import { isFunction, isPlainObject, isString } from "@thi.ng/checks";
 import { illegalArgs } from "@thi.ng/errors";
@@ -270,6 +270,20 @@ export const node1 = (
     xform ? src[inputID].subscribe(xform, id) : src[inputID].subscribe({}, id)
 );
 
+/**
+ * Syntax sugar for `node()`, intended for nodes w/ 2 inputs, by default
+ * named `a` & `b` (but can be overridden).
+ *
+ * @param xform
+ * @param inputIDs
+ * @param reset
+ */
+export const node2 = (
+    xform: Transducer<IObjectOf<any>, any>,
+    inputIDs: Tuple<string, 2> = ["a", "b"],
+    reset = false
+) => node(xform, inputIDs, reset);
+
 /**
  * Helper function to verify given object of inputs has required input IDs.
  * Throws error if validation fails.

packages/rstream-graph/src/nodes/math.ts

@@ -1,7 +1,7 @@
 import { IObjectOf } from "@thi.ng/api";
 import { map } from "@thi.ng/transducers";
 import { NodeFactory } from "../api";
-import { node } from "../graph";
+import { node, node2 } from "../graph";
 
 /**
  * Addition node.
@@ -42,17 +42,15 @@ export const mul: NodeFactory<number> = node(
  *
  * Inputs: `a`, `b`
  */
-export const sub: NodeFactory<number> = node(
-    map((ports: IObjectOf<number>) => ports.a - ports.b),
-    ["a", "b"]
+export const sub: NodeFactory<number> = node2(
+    map((ports: IObjectOf<number>) => ports.a - ports.b)
 );
 
 /**
  * Division node.
  *
  * Inputs: `a`, `b`
  */
-export const div: NodeFactory<number> = node(
-    map((ports: IObjectOf<number>) => ports.a / ports.b),
-    ["a", "b"]
+export const div: NodeFactory<number> = node2(
+    map((ports: IObjectOf<number>) => ports.a / ports.b)
 );