jorendorff

This was written in response to: https://twitter.com/hillelogram/status/1227118562373963776

---

People mix the predicate "If a directed graph is a tree, it's a DAG" with the proposition "For all directed graphs, if a directed graph is a tree, it's a DAG".

First, for simplification: let's assume we're talking here about all graphs in the world with up to 10 nodes to be able to enumerate them. Also, note that we're talking about directed, not undirected, graphs.

To prove the proposition "For all..." is true, which is "(For graph G1, if it's a tree, it's a DAG) AND (For graph G2, if it's a tree, it's a DAG) AND...", since it's ANDs, we need to prove (For graph G1, if...) is true and we need to prove (For graph G2, if...) is true, ... etc.

jorendorff

use std::fmt::Debug;

struct Reader<'a> {
    buf: &'a [u8],
}

impl<'a> Reader<'a> {
    fn read<'b>(&'b mut self, len: usize) -> Result<&'a [u8], ()> {
        if len <= self.buf.len() {
            let (read, remains) = self.buf.split_at(len);

jorendorff

import random

random.seed()

def flip():
  return random.choice([True, False])

def run():
  b = flip()
  n = 1

jorendorff

extern crate termion;
use std::io::{Write, Stdout, stdout, stdin};
use termion::event::{Key, Event};
use termion::input::TermRead;
use termion::raw::{IntoRawMode, RawTerminal};
use termion::screen::AlternateScreen;


pub struct Editor {
    screen: AlternateScreen<Stdout>,

jorendorff

# Some more privileged methods, with some private data.
class Availability:
    def __init__(self):
        self._is_open = False

    def open(self):
        self._is_open = True

    def close(self):
        self._is_open = False

jorendorff

CIS claims 72 terrorists have come to the US from the 7 countries in Trump's travel ban. Here's what I learned.

• These cases aren't about actual attacks in the U.S. The Ninth Circuit said "The Government has pointed to no evidence that any alien from any of the countries named in the Order has perpetrated a terrorist attack in the United States." The reason I got into this mess is people claiming the court lied. They did not lie. Nor is CIS lying. This list is mainly people who aided terrorist groups, and a few FBI sting operations. In all 11 cases I got to, no attack occurred.

• These people were not all admitted to the U.S. under current vetting procedures. See the last case listed below.

Cases

I had an hour to spend. I looked into these cases, mostly relying on news accounts.

jorendorff

# To run this code, you'll need the sample data (133 MB download, unzips to 492 MB):
#     http://bit.ly/2avfASU
#     tar xjf sample.tar.bz2

defmodule Elindex.Searcher do
  def search(word) do
    File.ls!("sample")
    |> Stream.map(fn(filename) ->
         fn ->
            Path.join("sample", filename)

jorendorff

function evaluate(context, expr, origExpr, onSuccess, onError)
{
    var result;
    var commandLine = createFirebugCommandLine(context, win);
    // gets the debuggee object: 
    var dglobal = DebuggerLib.getDebuggeeGlobal(context.window, context);
    var resObj;

    // that works:
    commandLine.someFunction = dglobal.makeDebuggeeValue(function()

jorendorff

Good-bye constructor functions?

tl;dr

Constructor function were workaround to specify constructor for a class without class. Now, having class nothing presribes the class being equivalent to its constructor. It always brought confusion and now with constructor empowered, it brings two-space problem. The class keyword can return plain objects, which have [[Construct]] calling the constructor of the class.

Problems

jorendorff

require 'video_title_validator'

class Post < ActiveRecord::Base
  attr_accessible :body, :title, :image, :video_title, :video_url

  validates :video_url, :presence => true, :if => :video_title_present?

  def video_title_present?
    puts "YES IT IS BEING CALLED, FINALLY"
    !self.video_title.blank?