From cba741f572c332a0f34bc8db1e9e78c2d788eb29 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 17 May 2026 21:38:15 +0000
Subject: [PATCH 1/2] Initial plan


From 0a5d448e097f110e96cc6fa2467811873a461342 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 17 May 2026 21:40:39 +0000
Subject: [PATCH 2/2] Initialize TypeScript NumPy-style core API

---
 .gitignore          |  2 ++
 README.md           | 24 +++++++++++++-
 package-lock.json   | 30 ++++++++++++++++++
 package.json        | 17 ++++++++++
 src/index.ts        | 77 +++++++++++++++++++++++++++++++++++++++++++++
 test/numpst.test.js | 25 +++++++++++++++
 tsconfig.json       | 46 +++++++++++++++++++++++++++
 7 files changed, 220 insertions(+), 1 deletion(-)
 create mode 100644 .gitignore
 create mode 100644 package-lock.json
 create mode 100644 package.json
 create mode 100644 src/index.ts
 create mode 100644 test/numpst.test.js
 create mode 100644 tsconfig.json

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b947077
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+node_modules/
+dist/
diff --git a/README.md b/README.md
index 1c3e3c7..c213cde 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,23 @@
-# numpst
\ No newline at end of file
+# numpst
+
+A small TypeScript port of common NumPy-style vector operations.
+
+## API
+
+- `array(iterable)`
+- `zeros(length)`
+- `ones(length)`
+- `arange(start, stop?, step?)`
+- `add(a, b)`
+- `subtract(a, b)`
+- `multiply(a, b)`
+- `divide(a, b)`
+- `sum(values)`
+- `mean(values)`
+
+## Development
+
+```bash
+npm install
+npm test
+```
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..172e560
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,30 @@
+{
+  "name": "numpst",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "numpst",
+      "version": "1.0.0",
+      "license": "ISC",
+      "devDependencies": {
+        "typescript": "^6.0.3"
+      }
+    },
+    "node_modules/typescript": {
+      "version": "6.0.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-6.0.3.tgz",
+      "integrity": "sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    }
+  }
+}
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..991951d
--- /dev/null
+++ b/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "numpst",
+  "version": "1.0.0",
+  "description": "TypeScript port of NumPy",
+  "main": "dist/index.js",
+  "scripts": {
+    "test": "npm run build && node --test test",
+    "build": "tsc"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "typescript": "^6.0.3"
+  },
+  "types": "dist/index.d.ts"
+}
diff --git a/src/index.ts b/src/index.ts
new file mode 100644
index 0000000..435cb9f
--- /dev/null
+++ b/src/index.ts
@@ -0,0 +1,77 @@
+export type VectorLike = number[];
+
+const assertSameLength = (a: VectorLike, b: VectorLike): void => {
+  if (a.length !== b.length) {
+    throw new Error(`Shape mismatch: ${a.length} !== ${b.length}`);
+  }
+};
+
+export const array = (values: Iterable<number>): number[] => [...values];
+
+export const zeros = (length: number): number[] => {
+  if (!Number.isInteger(length) || length < 0) {
+    throw new Error("length must be a non-negative integer");
+  }
+  return new Array<number>(length).fill(0);
+};
+
+export const ones = (length: number): number[] => {
+  if (!Number.isInteger(length) || length < 0) {
+    throw new Error("length must be a non-negative integer");
+  }
+  return new Array<number>(length).fill(1);
+};
+
+export const arange = (start: number, stop?: number, step = 1): number[] => {
+  if (step === 0) {
+    throw new Error("step must not be zero");
+  }
+
+  const from = stop === undefined ? 0 : start;
+  const to = stop === undefined ? start : stop;
+  const out: number[] = [];
+
+  if (step > 0) {
+    for (let i = from; i < to; i += step) {
+      out.push(i);
+    }
+  } else {
+    for (let i = from; i > to; i += step) {
+      out.push(i);
+    }
+  }
+
+  return out;
+};
+
+const elementwise = (
+  a: VectorLike,
+  b: VectorLike,
+  op: (left: number, right: number) => number,
+): number[] => {
+  assertSameLength(a, b);
+  return a.map((value, idx) => op(value, b[idx]!));
+};
+
+export const add = (a: VectorLike, b: VectorLike): number[] =>
+  elementwise(a, b, (left, right) => left + right);
+
+export const subtract = (a: VectorLike, b: VectorLike): number[] =>
+  elementwise(a, b, (left, right) => left - right);
+
+export const multiply = (a: VectorLike, b: VectorLike): number[] =>
+  elementwise(a, b, (left, right) => left * right);
+
+export const divide = (a: VectorLike, b: VectorLike): number[] =>
+  elementwise(a, b, (left, right) => left / right);
+
+export const sum = (values: VectorLike): number =>
+  values.reduce((acc, current) => acc + current, 0);
+
+export const mean = (values: VectorLike): number => {
+  if (values.length === 0) {
+    throw new Error("cannot compute mean of empty array");
+  }
+
+  return sum(values) / values.length;
+};
diff --git a/test/numpst.test.js b/test/numpst.test.js
new file mode 100644
index 0000000..10e5912
--- /dev/null
+++ b/test/numpst.test.js
@@ -0,0 +1,25 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+const np = require('../dist/index.js');
+
+test('array construction helpers', () => {
+  assert.deepEqual(np.array([1, 2, 3]), [1, 2, 3]);
+  assert.deepEqual(np.zeros(3), [0, 0, 0]);
+  assert.deepEqual(np.ones(2), [1, 1]);
+  assert.deepEqual(np.arange(4), [0, 1, 2, 3]);
+  assert.deepEqual(np.arange(1, 6, 2), [1, 3, 5]);
+});
+
+test('vector arithmetic', () => {
+  const a = [1, 2, 3];
+  const b = [4, 5, 6];
+  assert.deepEqual(np.add(a, b), [5, 7, 9]);
+  assert.deepEqual(np.subtract(b, a), [3, 3, 3]);
+  assert.deepEqual(np.multiply(a, b), [4, 10, 18]);
+  assert.deepEqual(np.divide(b, a), [4, 2.5, 2]);
+});
+
+test('reductions', () => {
+  assert.equal(np.sum([1, 2, 3, 4]), 10);
+  assert.equal(np.mean([1, 2, 3, 4]), 2.5);
+});
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..3ae2719
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,46 @@
+{
+  // Visit https://aka.ms/tsconfig to read more about this file
+  "compilerOptions": {
+    // File Layout
+    "rootDir": "src",
+    "outDir": "dist",
+
+    // Environment Settings
+    // See also https://aka.ms/tsconfig/module
+    "module": "commonjs",
+    "target": "es2020",
+    "types": [],
+    // For nodejs:
+    // "lib": ["esnext"],
+    // "types": ["node"],
+    // and npm install -D @types/node
+
+    // Other Outputs
+    "sourceMap": true,
+    "declaration": true,
+    "declarationMap": true,
+
+    // Stricter Typechecking Options
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+
+    // Style Options
+    // "noImplicitReturns": true,
+    // "noImplicitOverride": true,
+    // "noUnusedLocals": true,
+    // "noUnusedParameters": true,
+    // "noFallthroughCasesInSwitch": true,
+    // "noPropertyAccessFromIndexSignature": true,
+
+    // Recommended Options
+    "strict": true,
+    "jsx": "react-jsx",
+    "verbatimModuleSyntax": false,
+    "isolatedModules": true,
+    "noUncheckedSideEffectImports": true,
+    "moduleDetection": "force",
+    "skipLibCheck": true,
+
+    "esModuleInterop": true,
+  }
+}