Jacek Podkanski bigos

Simplified installation

already I have

choco msys2 emacs

Install GHC

open cmd as administrator

Press Windows button, in ‘Type to search’ type cmd, right-click on Command Promp Desktop app and select Run as administrator.

lines to paste in cmd

New attempt

instaled new test VM

updated the language and found that Power shell responds to

choco version
Chocolatey v0.10.8

installed MSYS2

Used Admin cmd

Missing Instructions

Haskell installation experiment

download core Haskell platform

https://www.haskell.org/platform/

Install it to a destination folder without spaces

update mingw64 terminal

pacman -Syu, then kill the terminal when prompted restart it and resume update with pacman -Su

install required packages

pacman -S mingw64/mingw-w64-x86_64-pkg-config mingw64/mingw-w64-x86_64-clutter mingw64/mingw-w64-x86_64-gobject-introspection

Reader Macros in Common Lisp

This post also appears on lisper.in.

Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.

Paul Graham explains them very well in [On Lisp][] (Chapter 17, Read-Macros):

The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.

	;;; tree traversal

	(defparameter tr '((s
	(num
	(dig
	(1))
	(diga
	(da
	(2a))
	(da

	{-# LANGUAGE OverloadedStrings #-}
	module Main where


	import qualified GI.Gtk as GI (init,
	main)
	import GI.Gtk (boxNew,
	binGetChild,
	boxPackStart,
	checkButtonNew,

	require 'csv'
	# helper code for importing csv orders
	class ReceiptImporter
	attr_reader :found_errors, :invalid_receipts, :skipped_receipts, :imported_receipts, :total_receipts

	def initialize(filepath, mode)
	@depot = Depot.find Depot.current
	@mode = mode
	@record_types = { 'FH' => :file_header,
	'RH' => :receipt_header,

	(defun max-int (a)
	(cond ((null a)
	(error "empty list"))
	((null (cdr a))
	(car a))
	(T
	(max (car a)
	(max-int (cdr a))))))

	;; you can use this function to unfold s-exps so that newline follows after one or more closing brackets
	(defun unfold-lisp ()
	"Unfold lisp code."
	(interactive)
	(search-forward ")")
	(backward-char)
	(search-forward " ")
	(newline-and-indent))

	(global-set-key (kbd "s-0") 'unfold-lisp)

	<html>
	<head>
	<title>Colour selection</title>
	<style>
	.grey{color:#777;}
	.red{color:red;}
	.yellow{color: yellow;}
	.orange-red{color: #ff4500;}
	.tomato{color: #ff6347;}
	.light-coral{color: #f08080;}