Will Temple willmtemple

TypeSpec LDM: `extern fn` Declarations

This feature introduces a new kind of declaration to TypeSpec:

'extern' 'fn' Identifier '(' Parameter* ')' (':' TypeRef)? ';'

	packages/http/lib/auth.tsp
	89:model ApiKeyAuth<TLocation extends ApiKeyLocation, TName extends string> {

	packages/http/lib/http.tsp
	15:model Response<Status> {
	30:model Body<T> {
	103:model PlainData<T> {

	packages/json-schema/lib/main.tsp
	158:model Json<T> {

	/**
	* Copyright (c) Will Temple 2022
	*
	* # ELEMENTAL TYPE SYSTEM
	*
	* This module describes an elemental type system composed of only five
	* fundamental type forms that I find to be highly expressive in simply-typed
	* contexts.
	*
	* By simply-typed, I mean systems that do not include type-binding.

	declare class Vehicle {
	engines: number;
	ignition(): void;
	drive(): void;
	}

	declare class Car extends Vehicle {
	wheels: number;
	}

	{
	"scripts": {
	"rush:denial": "rushx clean && rushx build",
	"rush:anger": "rush clean && rush rebuild",
	"rush:bargaining": "rush clean && rush purge && rush update --full && rush rebuild",
	"rush:depression": "while true; do rm -rf common/temp && npm run rush:bargaining; done",
	"rush:acceptance": "cd ..; rm -rf azure-sdk-for-js; git clone https://github.com/azure/azure-sdk-for-js.git"
	}
	}

	// This uses my modified version of typescript from my branch github.com/willmtemple/typescript#alchemy
	import * as ts from "typescript/built/local/typescript";

	import * as fs from "fs";
	import * as os from "os";

	import { promisify } from "util";

	const readFile = promisify(fs.readFile);

	declare export function match<
	DiscriminatedUnion extends { [K in Discriminator]: string \| number },
	Pattern extends Partial<
	{
	[K in DiscriminatedUnion[Discriminator]]: (
	v: Extract<DiscriminatedUnion, { kind: K }>
	) => any;
	}
	>,
	Discriminator extends string \| number = "kind"