gtkatakura

Basic QTT

Quantitative type theory (QTT) is an extension of dependent type theory which allows us to track the number of computational (non-erased) uses of variables in well-typed lambda terms. With such usage information, QTT allows us to combine dependent types with substructural types, such as linear, affine or relevant types.

While in a Martin-Löf style type theory typing judgments are of form x1 : A1, ..., xn : An ⊢ b : B, in QTT the bindings in the context

Programming as Theory Building

Peter Naur

Peter Naur's classic 1985 essay "Programming as Theory Building" argues that a program is not its source code. A program is a shared mental construct (he uses the word theory) that lives in the minds of the people who work on it. If you lose the people, you lose the program. The code is merely a written representation of the program, and it's lossy, so you can't reconstruct

List of working and non working fetch requests in RN Android

React Native version: 0.62.2
Affected platform: Android (iOS is working fine)
Affected stages: debug & release
Affected JS engines: jsc, v8 & Hermes
Used phones: Redmi Note
Tried to comment out initializeFlipper without success
Tried to set FLIPPER_VERSION=0.39.0 without success
The problem also happens in Postman on macOS with the "SSL certificate verification" option enabled, although the failing URLs don't show any SSL warning in Chrome browser

Charles Proxy Android

Note: Consider using mitmproxy instead of Charles. There is better, more recent, documentation for using mitmproxy on Android.

Steps

1. Add the Network Security Configuration to your app

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

	const path = require('path');

	const webpack = require('webpack');

	const WebpackNodeExternals = require('webpack-node-externals');
	const ReloadServerPlugin = require('reload-server-webpack-plugin');

	const cwd = process.cwd();

	module.exports = {

	import React from 'react'
	import { Link } from 'systems/Core/Link'
	import css from 'styled-jsx/css'

	export const Header = () => {
	return (
	<header className="Root">
	<img src="/logo.svg" width={100} />
	<div className="MainMenu">
	<ul className="MenuList">

	ruby '2.7.1'

	gem 'rails', github: 'rails/rails'
	gem 'tzinfo-data', '>= 1.2016.7' # Don't rely on OSX/Linux timezone data

	# Action Text
	gem 'actiontext', github: 'basecamp/actiontext', ref: 'okra'
	gem 'okra', github: 'basecamp/okra'

	# Drivers

	import { fromGlobalId } from 'graphql-relay';
	import { Model, Types } from 'mongoose';

	// returns an ObjectId given an param of unknown type
	export const getObjectId = (target: string \| Model<any> \| Types.ObjectId): Types.ObjectId \| null => {
	if (target instanceof Types.ObjectId) {
	return new Types.ObjectId(target.toString());
	}

	if (typeof target === 'object') {

	import transformTypescript from "@babel/plugin-transform-typescript"
	import {declare} from "@babel/helper-plugin-utils"
	import {types as t, PluginObj, Node, NodePath} from "@babel/core"
	import template from "@babel/template"
	import {
	TSTypeAliasDeclaration,
	TSType,
	TSTypeParameter,
	TSUnionType,
	TSTypeReference,