charting refactor into shapes, not debugged

src/common.js

@@ -0,0 +1,44 @@
+export function mixin(child, ...parents) {
+    // child is modified directly, assigning fields from parents that are missing in child.  parents fields are
+    // assigned by parents order, highest priority first
+    for( const parent of parents ) {
+        for ( const key in parent) {
+            if (parent.hasOwnProperty(key) && !child.hasOwnProperty(key)) {
+                child[key] = parent[key];
+            }
+        }
+    }
+    return child;
+}
+
+
+export function prototype(parent, child) {
+    const result = Object.create(parent);
+    Object.assign(result, child)
+    return result
+}
+
+export function invokeCallback(cbs, prop, ...args) {
+    if (prop in cbs) cbs[prop].call(cbs, ...args)
+}
+
+export function invokeCallbacks(callbacks, prop, ...args) {
+    if (!callbacks) return
+    callbacks.forEach((cb)=>invokeCallback(cb, prop, ...args))
+}
+
+
+export function encodeIEE754(value) {
+    const buffer = new ArrayBuffer(4);
+    const view = new DataView(buffer);
+    view.setFloat32(0, value, false /* big endian */);
+    return view.getUint32(0, false);
+}
+
+
+export function decodeIEE754(value) {
+    const buffer = new ArrayBuffer(4);
+    const view = new DataView(buffer);
+    view.setUint32(0, value, false)
+    return view.getFloat32(0, false)
+}