chitchcock

Stevey's Google Platforms Rant

I was at Amazon for about six and a half years, and now I've been at Google for that long. One thing that struck me immediately about the two companies -- an impression that has been reinforced almost daily -- is that Amazon does everything wrong, and Google does everything right. Sure, it's a sweeping generalization, but a surprisingly accurate one. It's pretty crazy. There are probably a hundred or even two hundred different ways you can compare the two companies, and Google is superior in all but three of them, if I recall correctly. I actually did a spreadsheet at one point but Legal wouldn't let me show it to anyone, even though recruiting loved it.

I mean, just to give you a very brief taste: Amazon's recruiting process is fundamentally flawed by having teams hire for themselves, so their hiring bar is incredibly inconsistent across teams, despite various efforts they've made to level it out. And their operations are a mess; they don't real

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

Francesco149

this has been rewritten yet again as most workarounds aren't required anymore since wine 3+

example video of the final result: https://www.youtube.com/watch?v=zkqzQoeOGfU

with touchscreen: https://www.youtube.com/watch?v=GcIrlorWmaQ

performance is indistinguishable from windows. there might be a very slight ~25ms sound latency which is easily compensated with +25 local offset

tested on

Hirrolot

Supercompilation is a deep program transformation technique due to V. F. Turchin, a prominent computer scientist, cybernetician, physicist, and Soviet dissident. He described the concept as follows [^supercompiler-concept]:

A supercompiler is a program transformer of a certain type. The usual way of thinking about program transformation is in terms of some set of rules which preserve the functional meaning of the program, and a step-by-step application of these rules to the initial program. ... The concept of a supercompiler is a product of cybernetic thinking. A program is seen as a machine. To make sense of it, one must observe its operation. So a supercompiler does not transform the program by steps; it controls and observes (SUPERvises) the running of the machine that is represented by the program; let us call this machine M₁. In observing the operation of

joepie91

Lower precedence means a stronger binding; ie. this list is sorted from strongest to weakest binding, and in the case of equal precedence between two operators, the associativity decides the binding.

Prec	Abbreviation	Example	Assoc	Description
1	SELECT	e . attrpath [or def]	none	Select attribute denoted by the attribute path attrpath from set e. (An attribute path is a dot-separated list of attribute names.) If the attribute doesn’t exist, return default if provided, otherwise abort evaluation.
2	APP	e1 e2	left	Call function e1 with argument e2.
3	NEG	-e	none	Numeric negation.
4	HAS_ATTR	e ? attrpath	none	Test whether set e contains the attribute denoted by attrpath; return true or false.
5	CONCAT	e1 ++ e2	right	List concatenation.
6	MUL	e1 * e2	le

lelandbatey

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

pkhuong

#!/usr/bin/env sed -re s|^|\x20\x20\x20\x20| -e s|^\x20{4}\x23\x23{(.*)$|<details><summary>\1</summary>\n| -e s|^\x20{4}\x23\x23}$|\n</details>| -e s|^\x20{4}\x23\x23\x20?|| -e s|\x0c|\x20|

license, imports

# Yannakakis.py by Paul Khuong
#
# To the extent possible under law, the person who associated CC0 with
# Yannakakis.py has waived all copyright and related or neighboring rights
# to Yannakakis.py.

andyrbell

# use ImageMagick convert
# the order is important. the density argument applies to input.pdf and resize and rotate to output.pdf
convert -density 90 input.pdf -rotate 0.5 -attenuate 0.2 +noise Multiplicative -colorspace Gray output.pdf

edolstra

General notes

• nix-channel and ~/.nix-defexpr are gone. We'll use $NIX_PATH (or user environment specific overrides configured via nix set-path) to look up packages. Since $NIX_PATH supports URLs nowadays, this removes the need for channels: you can just set $NIX_PATH to e.g. https://nixos.org/channels/nixos-15.09/nixexprs.tar.xz and stay up to date automatically.

• By default, packages are selected by attribute name, rather than the name attribute. Thus nix install hello is basically equivalent to nix-env -iA hello. The attribute name is recorded in the user environment manifest and used in upgrades. Thus (at least by default) hello won't be upgraded to helloVariant.

  @vcunat suggested making this an arbitrary Nix expression rather than an attrpath, e.g. firefox.override { enableFoo = true; }. However, such an expression would not have a key in the user environment, unlike an attrpath. Better to require an explicit flag for this.

TBD: How to deal with search path clashes.

edolstra

Nix Flake MVP

Goals

• To provide Nix repositories with an easy and standard way to reference other Nix repositories.

• To allow such references to be queried and updated automatically.

• To provide a replacement for nix-channel, NIX_PATH and Hydra