Marduk Bolaños mardukbp

So you want to write a sync system for a web app with offline and realtime support? Good luck. You might find the following resources useful.

Overview articles

Database in a browser, a spec (Stepan Parunashvili)

What problem are we trying to solve with a sync system?
The web of tomorrow (Nikita Prokopov)

Since it has come up a few times, I thought I’d write up some of the basic ideas around domain modeling in Clojure, and how they relate to keyword names and Specs. Firmly grasping these concepts will help us all write code that is simpler, cleaner, and easier to understand.

Clojure is a data-oriented language: we’re all familiar with maps, vectors, sets, keywords, etc. However, while data is good, not all data is equally good. It’s still possible to write “bad” data in Clojure.

“Good” data is well defined and easy to read; there is never any ambiguity about what a given data structure represents. Messy data has inconsistent structure, and overloaded keys that can mean different things in different contexts. Good data represents domain entities and a logical model; bad data represents whatever was convenient for the programmer at a given moment. Good data stands on its own, and can be reasoned about without any other knowledge of the codebase; bad data is deeply and tightly coupled to specific generating and

Create a Project using Django, preact and bulma

Python setup

Init folders:

mkdir project_name
cd project_name
pipenv --shell
pipenv install django djangorestframework django_rest_knox

##Examples of Higher-Order Functions in XQuery

Here are a few examples of higher-order functions in XQuery. For more examples, see the very nice discussion of higher-order functions in XQuery 3.0 at the BaseX website.

N.B. In some implementations, these functions may not be implemented or may have different names/function signatures. The first four functions have been tested using Saxon PE and the second four using Zorba.

An introduction to recursion in XQuery

Created: Nov 28, 2017
Updated: Nov 29, 2017: Now covers transformation of XML documents

Recursion is a powerful programming technique, but the idea is simple: instead of performing a single operation, a function calls itself repeatedly to whittle through a larger task. In XQuery, recursion can be used to accomplish complex tasks on data that a plain FLWOR expression (which iterates through a sequence) cannot, such as transforming an entire XML document from one format into another, like TEI or DocBook into HTML, EPUB, LaTeX, or XSL-FO. Transforming a document is well-suited to recursion because each of the document's nodes may need to be examined and manipulated based on the node's type, name, and location in the document; and once a node has been processed, the transformation must continue processing the nodes' children and descendants until the deepest leaf node has been processed. But learning the technique of recursion is often hard for a beginning program

Type vs Data Constructors

In a data declaration, a type constructor is the thing on the left hand side of the equals sign. The data constructor(s) are the things on the right hand side of the equals sign. You use type constructors where a type is expected, and you use data constructors where a value is expected.

Data constructors

To make things simple, we can start with an example of a type that represents a colour.

data Colour = Red | Green | Blue

SVG fragment builds for reveal.js

Basic use case

make an SVG (maybe in inkscape)
- save it someplace reveal.js can find it (maybe next to your presentation)
- figure out how to identify them (maybe use named layers)
in reveal.js/index.html
- add reveal-svg-fragment.js as a dependency
- in a <section> of reveal.js markup
add data-svg-fragment="" to something, e.g.

	<# :
	@echo off & setlocal & set __args=%* & pwsh.exe -NoProfile -Command Invoke-Expression ('. { ' + (Get-Content -LiteralPath ""%~f0"" -Raw) + ' }' + $env:__args) & exit /b %ERRORLEVEL%
	#> Add-Type @'
	// ========== BEGIN C# CODE ==========
	using System;
	using System.Runtime.InteropServices;

	public class Program
	{
	public static void Main(string[] args)

	from BaseHTTPServer import BaseHTTPRequestHandler
	import urlparse, json

	class GetHandler(BaseHTTPRequestHandler):

	def do_GET(self):
	parsed_path = urlparse.urlparse(self.path)
	message = '\n'.join([
	'CLIENT VALUES:',
	'client_address=%s (%s)' % (self.client_address,

	"**************************************************************************
	* Allowable characters: *
	* - a-z *
	* - A-Z *
	* - 0-9 *
	* - .+/\~<>@%\|&?
	* - blank, tab, cr, ff, lf *
	* *
	* Variables: *
	* - variables must be declared before use *