Started work on a beat data structure

src/Beat.ts

@@ -0,0 +1,49 @@
+import BeatUnit from "./BeatUnit";
+
+type BeatInitOptions = {
+    timeSig: {
+        up: number,
+        down: number,
+    },
+    bars: number,
+};
+
+export default class Beat {
+    private timeSigUp: number = 4;
+    private timeSigDown: number = 4;
+    private units: BeatUnit[] = [];
+
+    constructor(options?: BeatInitOptions) {
+        this.setTimeSignature(options.timeSig.up, options.timeSig.down);
+        this.setBars(options.bars);
+    }
+
+    setTimeSignature(up: number, down: number): void {
+        if (Beat.isValidTimeSigRange(up)) {
+            this.timeSigUp = up | 0;
+        }
+        if (Beat.isValidTimeSigRange(down)) {
+            this.timeSigDown = down | 0;
+        }
+    }
+
+    setBars(barCount: number): void {
+        if (barCount*this.timeSigUp < this.units.length) {
+            this.units.splice(barCount, this.units.length - barCount);
+        } else if (barCount > this.bars) {
+            for (let i = 0; i < barCount; i++) {
+                this.units.push(new BeatUnit());
+            }
+        }
+
+        this.bars = barCount;
+    }
+
+    stringify(): string {
+        return "I am a Beat";
+    }
+
+    private static isValidTimeSigRange(sig: number): boolean {
+        return sig >= 2 && sig <= 64;
+    }
+}