dabeaz

Code from PyCon India 2019 Keynote Talk
David Beazley (https://www.dabeaz.com)
======================================

This code is presented "as is" and represents what was live-coded
during my closing keynote presentation at PyCon India, Chennai,
October 13, 2009.  I have made no changes to the files.

Requires:  Python 3.6+, numpy, pygame

alf-p-steinbach

Why COW was deemed ungood for std::string.

COW, short for copy on write, is a way to implement mutable strings so that creating strings and logically copying strings, is reduced to almost nothing; conceptually they become free operations like no-ops.

Basic idea: to share a data buffer among string instances, and only make a copy for a specific instance (the copy on write) when that instance's data is modified. The general cost of this is only an extra indirection for accessing the value of a string, so a COW implementation is highly desirable. And so the original C++ standard, C++98, and its correction C++03, had special support for COW implementations, and e.g. the g++ compiler's std::string implementations used COW.

So why was that support dropped in C++11?

In particular, would the same reason or reasons apply to a reference counted immutable string value class?

voltrevo

Comparison of Typescript and Flow

Common Features

• Lots of type inference

• Null/undefined checking

Similar syntax

pkazmierczak

import asyncio


@asyncio.coroutine
def factorial(name, number):
    f = 1
    for i in range(2, number + 1):
        print("Task %s: Compute factorial(%d)..." % (name, i))
        yield from asyncio.sleep(1)
        f *= i

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

willprice

# Ruby is our language as asciidoctor is a ruby gem.
lang: ruby
before_install:
  - sudo apt-get install pandoc
  - gem install asciidoctor
script:
  - make
after_success:
  - .travis/push.sh
env:

robo-corg

from IPython.kernel.zmq.kernelapp import IPKernelApp
from IPython.utils.frame import extract_module_locals
import sys

# Code lifted from IPython/kernel/zmq/embed.py
def embed_kernel_noloop(module=None, local_ns=None, **kwargs):
    """Embed and start an IPython kernel in a given scope
    returning function that can be used to pump a single event
    
    Parameters

sebfisch

Delimited Continuations

Delimited continuations manipulate the control flow of programs. Similar to control structures like conditionals or loops they allow to deviate from a sequential flow of control.

We use exception handling as another example for control flow manipulation and later show how to implement it using delimited continuations. Finally, we show that nondeterminism can also be expressed using delimited continuations.

Exception Handling

henrik

tmux cheatsheet

As configured in my dotfiles.

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