From 7699b5f9f01697a4ac3dcdaf064e11d6d7afb7b0 Mon Sep 17 00:00:00 2001
From: Marton Lederer <marton@lederer.hu>
Date: Sun, 14 Apr 2024 11:28:02 +0200
Subject: [PATCH 1/3] feat: pow refactor wip

---
 src/Quantity.ts | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/Quantity.ts b/src/Quantity.ts
index 800c23b..21e778b 100644
--- a/src/Quantity.ts
+++ b/src/Quantity.ts
@@ -477,16 +477,31 @@ export default class Quantity {
   }
 
   /**
-   * Raise one quantity to the power of an integer. This can cause precision loss
+   * Raise one quantity to the power of another. This can cause precision loss
    * @param x Quantity to raise
    * @param y Exponent
    * @returns Result of the power operation
    */
-  static __pow(x: Quantity, y: number) {
-    if (!Number.isInteger(y)) {
-      throw new Error("Cannot raise Quantity to the power of a non-integer number");
+  static __pow(x: Quantity, y: Quantity | bigint) {
+    if (typeof y !== "bigint" && !Quantity.isQuantity(y)) {
+      throw new Error("Invalid exponent");
     }
-    if (y === 0) return new Quantity(0, x.#D);
+
+    // power of 0
+    if ((typeof y === "bigint" && y === 0n) || Quantity.isQuantity(y) && Quantity.eq(y, new Quantity(0n, y.#D))) {
+      return Quantity.__one(x.#D);
+    }
+
+    // integer power
+    if (typeof y === "bigint") {
+      return new Quantity(
+        x.#qty ** y,
+        x.#D ** y
+      )._convert(x.#D);
+    }
+
+    // ensure same denomination
+    [x, y] = Quantity.sameDenomination(x, y);
 
     let res = x.clone();
 
@@ -506,11 +521,11 @@ export default class Quantity {
   }
 
   /**
-   * Raise one quantity to the power of an integer (in-place). This can cause
+   * Raise one quantity to the power of another (in-place). This can cause
    * precision loss
    * @param y Exponent
    */
-  _pow(y: number) {
+  _pow(y: Quantity | bigint) {
     const res = Quantity.__convert(
       Quantity.__pow(this, y),
       this.#D

From fbe0def03816a97a216cef50191cc186c45061cb Mon Sep 17 00:00:00 2001
From: Marton Lederer <marton@lederer.hu>
Date: Sun, 14 Apr 2024 11:31:01 +0200
Subject: [PATCH 2/3] feat: negative pow wip

---
 src/Quantity.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Quantity.ts b/src/Quantity.ts
index 21e778b..97befc7 100644
--- a/src/Quantity.ts
+++ b/src/Quantity.ts
@@ -494,8 +494,13 @@ export default class Quantity {
 
     // integer power
     if (typeof y === "bigint") {
+      let newRaw = x.#qty ** (y > 0 ? y : -y);
+
+      // TODO: precision
+      if (y < 0) newRaw = 1n / newRaw;
+
       return new Quantity(
-        x.#qty ** y,
+        newRaw,
         x.#D ** y
       )._convert(x.#D);
     }

From 635b851649ff866857ab4f280d7bff9985e1c164 Mon Sep 17 00:00:00 2001
From: Marton Lederer <marton@lederer.hu>
Date: Mon, 15 Apr 2024 10:40:30 +0200
Subject: [PATCH 3/3] feat: support negative integer exponent

---
 src/Quantity.ts | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/Quantity.ts b/src/Quantity.ts
index 97befc7..2748a85 100644
--- a/src/Quantity.ts
+++ b/src/Quantity.ts
@@ -494,15 +494,19 @@ export default class Quantity {
 
     // integer power
     if (typeof y === "bigint") {
-      let newRaw = x.#qty ** (y > 0 ? y : -y);
-
-      // TODO: precision
-      if (y < 0) newRaw = 1n / newRaw;
-
-      return new Quantity(
-        newRaw,
+      const positivePower = new Quantity(
+        x.#qty ** (y > 0 ? y : -y),
         x.#D ** y
       )._convert(x.#D);
+
+      // negative exponent
+      if (y > 0) return positivePower;
+
+      // calculate negative exponent
+      const result = Quantity.__one(x.#D);
+      result._div(positivePower);
+
+      return result;
     }
 
     // ensure same denomination