webstrand

// Find the first item of a list.
export type Head<List extends readonly unknown[]> =
	0 extends keyof List ? List[0] : never;

// Find the last item of a list.
export type Last<List extends readonly unknown[]> =
	List["length"] extends 0 ? never
	: List extends [] ? never
	: number extends List["length"] ? List[1e+309]
	: List[Tail<List>["length"]];

webstrand

export interface Multimap<K, V> extends Map<K, V> {
	clear(): void;
	delete(key: K): boolean;
	delete(key: K, value: V): boolean;
	forEach(callbackfn: (value: V, key: K, map: this) => void, thisArg?: any): void;
	get(key: K): V | undefined;
	get(key: K, value: V): V | undefined;
	getAll(key: K): Set<V> | undefined;
	has(key: K): boolean;
	has(key: K, value: V): boolean;

webstrand

type Bind1<T> = T extends (this: unknown, ...args: infer V) => infer W ? (...args: V) => W : T extends (this: infer U, ...args: infer V) => infer W ? (this: U, ...args: V) => W : never;

export type EmitterParameters<T extends Emitter<any>> = T extends Emitter<infer U> ? Parameters<U> : [];

export interface EmitterEmittable<F extends (...args: any[]) => any, E extends (...args: any[]) => any = F>  {
	/*
	 * Emit the {@link values}.
	 *
	 * @param defaultContext Default context to bind each function's `this`.
	 * @param values Values to emit.

webstrand

/**
 * Unshift T onto the arguments list of S.
 */
type Unshift<S extends (...args: any[]) => any, T> = 
    S extends (...args: infer U) => any ? (arg: T, ...args: U) => any : never;

/**
 * Generate all the prefixes of T, not including
 * the nullary function nor T itself (unless T variadic).
 * Return types are not preserved.

webstrand

export type MapTree<K extends readonly [unknown, ...unknown[]], V> = {
	0: Map<K[number], V>,
	1: ((..._: K) => any) extends ((_: infer Head, ...__: infer Tail) => any)
		? Tail extends readonly [unknown, ...unknown[]]
			? Map<Head, MapTree<Tail, V>>
			: never
		: never
}[K extends readonly [unknown] ? 0 : 1] & {
	setKey(key: Readonly<K>, value: V): void;
	getKey(key: Readonly<K>): V | undefined;

webstrand

#!/usr/bin/perl
use strict;
use warnings;
use v5.26;
use Errno qw(EAGAIN EWOULDBLOCK EINTR);
use Fcntl qw(O_WRONLY);
STDOUT->autoflush(1);

# This is a tool like cat, except that it watches for STDOUT close and exits
# immediately.

webstrand

#!/usr/bin/perl
BEGIN{B:{$_=<<'STRAP'; chomp; exit (eval() // exit print STDERR $@)}}
#line 4 "STDIN"
	my $payload = "/tmp/payload";
	last unless $0 eq "-";
	my $F; do { local $^F=9999; open($F, '>', $payload) or die "$payload: $!" };
	$payload //= "/proc/self/fd/" . fileno($F);
	chmod(0744, $F) or die "$payload: $!";
	$/="\n__END__\n";
	print $F <<EVAL, scalar <STDIN> or die "$payload: $!";

webstrand

export type AppendV1<Tuple extends unknown[], Last> = 
  Tuple extends [infer _1] ? [_1, Last] :
  Tuple extends [infer _1, infer _2] ? [_1, _2, Last] :
  Tuple extends [infer _1, infer _2, infer _3] ? [_1, _2, _3, Last] :
  Tuple extends [infer _1, infer _2, infer _3, infer _4] ? [_1, _2, _3, _4, Last] :
  Tuple extends [infer _1, infer _2, infer _3, infer _4, infer _5] ? [_1, _2, _3, _4, _5, Last] :
  Tuple extends [infer _1, infer _2, infer _3, infer _4, infer _5, infer _6] ? [_1, _2, _3, _4, _5, _6, Last] :
  Tuple extends [infer _1, infer _2, infer _3, infer _4, infer _5, infer _6, infer _7] ? [_1, _2, _3, _4, _5, _6, _7, Last] :
  Tuple extends [infer _1, infer _2, infer _3, infer _4, infer _5, infer _6, infer _7, infer _8] ? [_1, _2, _3, _4, _5, _6, _7, _8, Last] :
  Tuple extends [infer _1, infer _2, infer _3, infer _4, infer _5, infer _6, infer _7, infer _8, infer _9] ? [_1, _2, _3, _4, _5, _6, _7, _8, _9, Last] :

webstrand

type Concat<U extends unknown[], V extends unknown[]> = {
	0: V,
	1: {
		0: U,
		1: [U[0], V[0]],
		2: [U[0], V[0], V[1]],
		3: [U[0], V[0], V[1], V[2]],
		4: [U[0], V[0], V[1], V[2], V[3]],
		5: [U[0], V[0], V[1], V[2], V[3], V[4]],
		6: [U[0], V[0], V[1], V[2], V[3], V[4], V[5]],

webstrand

import alias from "@rollup/plugin-alias";
import commonjs from "@rollup/plugin-commonjs";
import resolve from "@rollup/plugin-node-resolve";
import typescript from "@rollup/plugin-typescript";
import { createFilter } from "@rollup/pluginutils";
import surplusCompiler from "surplus/compiler";

function surplus({ include, exclude, sourceMap = false }) {
	const filter = createFilter(include, exclude);