gfredericks

(ns user.test
  (:require
   [clojure.test :refer [deftest is]]
   [clojure.test.check.results :as results]
   [clojure.test.check.generators :as gen]
   [clojure.test.check.properties :as prop]
   [clojure.test.check.clojure-test :refer [defspec]]))

(def gen-lazy-flatten-merge-by-keyfn
  (gen/elements [identity - #(mod % 17)]))

gfredericks

#+TITLE: What Are All These Class Files Even About?, and Other Stories
#+AUTHOR: Gary Fredericks
#+EMAIL: fredericksgary@gmail.com
#+DATE: 2018-11-30, Clojure/conj
#+CATEGORY: CONJ

* Latex Prelude
#+LaTeX_CLASS: beamer
#+LaTeX_CLASS_OPTIONS: [presentation]
#+BEAMER_THEME: Madrid

gfredericks

#!/usr/bin/env bash

#! top-of-file comments can be written using more #! lines, which 
#! is a valid comment in both clojure and bash

":";# alternately this works too

#! The construction below uses cross-language syntactic hackery to
#! specify the -Sdeps arg in a part of the file that's interpreted
#! by clojure as clojure syntax (i.e., not a line comment), so it 

gfredericks

(ns user.bijections
  (:refer-clojure :exclude [-> comp update])
  (:require [clojure.core :as core]
            [clojure.set :as set])
  (:import (java.util UUID)))

;;
;; Motivation:
;;
;; - avoid the edge cases inherent in allowing multiple

gfredericks

# Creates a git repo with 2^N files. N is the only arg. Creates a
# bare repo called "files".

require 'digest/sha1'
require 'zlib'

def filename(id)
  "objects/#{id[0...2]}/#{id[2..-1]}"
end

gfredericks

;; goals:
;; - unbounded distribution (arbitrarily large bigints can be generated,
;;   even for small `size`)
;; - but respects `size` -- with larger `size`, larger numbers are likely
;;   to be generated
;; - has a roughly 0.1% chance of generating an integer larger than 
;;   Double/MAX_VALUE (2^1024)

;; sizing background: https://github.com/clojure/test.check/blob/master/doc/growth-and-shrinking.md

gfredericks

;;
;; This file is clojure code that draws itself in a swing buffer
;; (https://twitter.com/pjstadig/status/771152863410188288)
;;

(defn draw-in-swing-buffer
  [s]
  (let [panel (doto (javax.swing.JPanel.)
                (.setLayout (java.awt.BorderLayout.)))
        frame (doto (javax.swing.JFrame.)

gfredericks

(def regular-quine
  "A regular quine. Evals to itself."
  '(let [thing '(list 'let ['thing (list 'quote thing)]
                      thing)]
     (list 'let ['thing (list 'quote thing)]
           thing)))

(= regular-quine (eval regular-quine)) ;; => true

(def counting-quine

gfredericks

Independent bindings in gen/let

The Problem

adapted from CLJ-1997

A common usage of gen/let might look something like this:

(gen/let [a gen-a

gfredericks

(ns user.defn+spec
  (:require [clojure.spec :as s]))

(defn non-&-sym? [x] (and (symbol? x) (not= '& x)))

(s/def ::arglist
  (s/cat :normal-args (s/* (s/cat :name non-&-sym?
                                  :spec-form (s/? (s/cat :- #{:-}
                                                         :spec ::s/any))))
         :varargs (s/? (s/cat :& #{'&}