[WIP] add replacements for System.Numerics Vector3 / Quaternion

[0x53A]

This adds replacements for System.Numerics Vector3 and Quaternion.

The reason for porting System.Numerics instead of binding an existing JS lib is that I want to run the same code serverside and clientside.

If you just need something for client side, i would still recomment to use a native js lib.

In the current WIP state this is just the subset I needed for my project, I plan to complete V3 and Q.

I do NOT plan to add everything from the package, i don't really care about Plane or Vector2, or Matrix_x_.

[alfonsogarciacaro]

Looks good! Seems SIMD support has been dropped from JS standards so I guess we don't need to worry about that. We don't need to add everything from System.Numerics (we already have BigInteger for example) and vectors/quaternions should already be very useful. Just let me know if you need any help with this.

[0x53A]

V3 / Q are the first replaced types to use member fields instead of member properties, so I had to modify FSharp2Fable a little bit.

When you have some time, could you review these changes please?

If that part is OK, then adding the remaining methods is just simple work.

[alfonsogarciacaro]

Looks good! I just added a minor comment :+1:

[0x53A]

after overriding equality, it now fails with this weird error:

[0x53A]

Ok, splitting the file into two so that there actually is a Vector3.js helped a bit, but equality still doesn't work:

[0x53A]

It somehow still accessed the old file that I had split, a git clean later it now fails with

So some code expects a file Vector3.js, some other code expects a System.Numerics.js ( ఠ ͟ʖ ఠ)

[0x53A]

It generated this weird code:

System.Numerics.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.Vector3$reflection = Vector3$reflection;
exports.Vector3$$$$002Ector$$Z7138B98C = Vector3$$$$002Ector$$Z7138B98C;
exports.Vector3$$$$002Ector$$Z69591B0C = Vector3$$$$002Ector$$Z69591B0C;

// ...

var _System = require("./System.Text");

var _Vector = _interopRequireDefault(require("./Vector3"));

var _Util = require("./Util");

// ...

Vector3.prototype.Equals = function (other$$1) {
  const this$$$8 = this;

  if (other$$1 instanceof _Vector.default) {
    const vother = other$$1;
    return Vector3$$Equals$$ZF6770AE(this$$$8, vother);
  } else {
    return false;
  }
};

// ...

Vector3.prototype.CompareTo = function (other$$2) {
  const this$$$10 = this;

  if ((0, _Util.equals)(other$$2, null)) {
    return (0, _String.toFail)((0, _String.printf)("other is null")) | 0;
  } else if (other$$2 instanceof _Vector.default) {
    const vother$$1 = other$$2;
    return (0, _Util.compareArrays)([this$$$10.X, this$$$10.Y, this$$$10.Z], [vother$$1.X, vother$$1.Y, vother$$1.Z]) | 0;
  } else {
    return (0, _String.toFail)((0, _String.printf)("invalid type, expected 'other' to be a Vector, but it is '%O'"))(_Reflection.obj) | 0;
  }
};

// ...

Note the var _Vector = _interopRequireDefault(require("./Vector3")); and the usages of _Vector.default.

so the typechecks are the issue.

Or rather the fact that structs should have an autogenerated parameterless ctor, but fable doesn't seem to generate one.

[alfonsogarciacaro]

Hmm, I'd have to look at the PR more carefully to find the problem but I see you're using bclType for the Vector3 replacement. This was create to automatically find the JS code using the namespace of the type as the file name and then resolving the mangling of the class and member names.

Also, numeric operations are tricky because they must be resolved in different places. You probably need to add the new BclQuaternion and BclVector3 to the following functions in Replacements.fs: applyOp, equals, compare, compareIf, getZero, getOne, defaultof