antonycourtney

-- This should all work with the DuckDb shell CLI, available from https://duckdb.org/docs/installation/index
-- (Select the CLI tab)

-- first create a view on the Parquet file:
CREATE VIEW books AS SELECT * from './goodreads_books.parquet';

-- take a look at the schema:
PRAGMA table_info(books);

-- Fix up one of the columns (book_id), converting it from VARCHAR to INTEGER (int32):

antonycourtney

A realistic RxJS app with diamond wiring

Consider the following user interface (inspired by Strava) for looking at time-series charts of network data:

Notes on this interface and my Rx implementation of it:

• Each chart (stacked vertically) charts a different metric (latency, packet loss and throughput) but over the same time period.
• As the user moves the mouse left and right on any chart, the vertical line (called the tracker) moves to track the mouse position on all charts. The number displayed in the gray box on the right is the value underneath the tracker for that metric.

antonycourtney

Received: by 10.140.161.21 with HTTP; Fri, 22 Feb 2008 06:35:48 -0800 (PST)
Message-ID: <3be64c030802220635i3380e50fh70bf62e0bdc6d5a0@mail.gmail.com>
Date: Fri, 22 Feb 2008 09:35:48 -0500
From: "Antony Courtney" <antony.courtney@gmail.com>
To: "Conal Elliott" <conal@conal.net>
Subject: Re: Fruit
Cc: Yampa-Users <yampa-users@cs.yale.edu>
In-Reply-To: <ea8ae9fb0802211906t232938c5wded0a56b35ceaa2d@mail.gmail.com>
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antonycourtney

/* @flow */

/* Paste this into https://flow.org/try/ to see the bug: */

const f = (lut: ?{[key: string]: number}): number => {
  
  // This correctly notices that we're doing a null check on lut:
  const testKey = 'fizz'
  const y = (lut != null) ? lut[testKey] : 0	
  

antonycourtney

/* @flow */

import * as Immutable from 'immutable'

/**
 * A timer object for use in OneRef-based immutable state
 *
 */

export type TimerUpdater = (f: (ts: Timer) => Timer) => void

antonycourtney

A really simple interpreter to use while learning about monads.  Based on
the paper "Monads for Functional Programming" by Phil Wadler.

the type of terms:

> data Term = Con Int
>	    | Div Term Term
>   deriving Show

antonycourtney

--
-- Some experiments with a Picture type based on an attribute-grammar
-- model of Layout

module FunPic where

import Haven

-- A type for representing the dimensions of a rectangle, as (width,height)
type Dimension = (Double,Double)

antonycourtney

import Color exposing (..)
import Graphics.Collage exposing (..)
import Graphics.Element exposing (..)
import List exposing (..)
import Signal exposing (..)
import Time exposing (..)
import Array

-- a square of the given width and color:
square : Float -> Color -> Form

antonycourtney

/**
 *
 * ChatAppState.js - atate of Chat application as an Immutable record
 *
 * Our application state consists of a collection of message threads
 * and a current thread (identified by its thread ID)
 *
 * Each thread id maps to a Thread (a collection of Message) 
 */
const emptyThread = new Thread();

antonycourtney

function invokeLater(f) {
  window.setTimeout(f, 0);
}