Expose simdjson via experimental flag or node:simdjson module #59373

I'm proposing for Node.js to expose the existing [simdjson]((https://github.com/simdjson/simdjson) integration through an experimental flag or via node:simdjson to enable those who want to use it without brower compatibility concern.

Background

Node.js currently includes simdjson internally but doesn't expose it to userland code AFAIU. During a recent discussion with @RafaelGSS on his livestream, it was mentioned that simdjson isn't enabled yet primarily due to insufficient testing to demonstrate API compatibility with browser JSON APIs.

Motivation

• Performance: simdjson offers significant parsing performance improvements over the standard JSON parser
• Community Testing: Exposing it experimentally would allow the community to extensively test compatibility
• Feedback Loop: Early access would help identify compatibility issues and API design concerns
• Innovation: Enables developers to experiment with high-performance JSON parsing in Node.js applications

Proposed Solution

Expose simdjson through one of these approaches:

Option 1: Experimental Flag

node --experimental-simdjson app.js

This would make simdjson available globally, potentially replacing or augmenting the standard JSON object.

Option 2: Dedicated Module

import { parse, stringify } from 'node:simdjson';
// or
const { parse, stringify } = require('node:simdjson');

Option 3: Hybrid Approach

Enable both the experimental flag and module access, allowing for different testing scenarios.

API Considerations

The exposed API may aim for compatibility (if desired) with:

• Standard JSON.parse() and JSON.stringify() signatures
• Browser JSON API behavior and edge cases
• Error handling patterns consistent with existing Node.js APIs

Implementation Considerations

• Mark the API as experimental with appropriate warnings
• Document known limitations or differences from standard JSON
• Provide clear migration path for when/if the API becomes stable
• Consider feature detection mechanisms for applications

I'd love to try out simdjson in my apps instead of the V8 JSON functions.

An experimental exposure could provide valuable data on real-world compatibility and performance, helping to make an informed decision about full integration while giving the community access to simdjson's performance benefits.