class Polynomial (#19)

Co-authored-by: Pablo Deymonnaz <[email protected]>

evm_bridge/src/polynomial.test.ts

@@ -0,0 +1,12 @@
+import { Field, Scalar } from "o1js";
+import { Polynomial } from "./polynomial.js";
+
+test("Evaluate polynomial", () => {
+    const coef = [Scalar.from(1), Scalar.from(2), Scalar.from(3)];
+    const p = new Polynomial(coef);
+    const x = Scalar.from(4);
+
+    let evaluation = p.evaluate(x);
+    let expected = Scalar.from(27);
+    expect(expected).toEqual(evaluation);
+});

evm_bridge/src/polynomial.ts

@@ -0,0 +1,17 @@
+import { Scalar } from "o1js"
+
+export class Polynomial {
+    coef: Array<Scalar>
+
+    constructor(coef: Array<Scalar>) {
+        this.coef = coef
+    }
+
+    evaluate(x: Scalar): Scalar {
+        let result = Scalar.from(0)
+        for (let i = 0; i < this.coef.length; i++) {
+            result = result.mul(x).add(this.coef[i])
+        }
+        return result
+    }
+}