taylorwood

(ns polydact.core
  (:import (clojure.lang IFn)
           (org.graalvm.polyglot Context Value)
           (org.graalvm.polyglot.proxy ProxyArray ProxyExecutable ProxyObject)))

(set! *warn-on-reflection* true)

(comment
  (do
    (def context

taylorwood

;; "human" date/time format parsing

(def human-time-parser
  (insta/parser
    "S = H (':' M)? ' '? P? (' ' Z)?
     H = #'[1-9]' | #'1[0-2]'
     M = #'0[0-9]' | #'[1-5][0-9]'
     P = AM | PM
     AM = 'A' 'M'?
     PM = 'P' 'M'?

taylorwood

GraalVM native image + deps.edn example

A CLI tool that reads JSON from stdin then writes it to stdout in EDN format.

Build

➜ clojure -A:native-image

taylorwood

(ns hickory-css-selectors
  "Convert CSS selectors into Hickory selectors."
  (:require [clojure.string :as cs]
            [hickory.select :as s]
            [instaparse.core :as p]
            [instaparse.transform :as pt]))

(def css-selector-parser
  "An incomplete and not very good parser for CSS selectors.
  https://drafts.csswg.org/selectors-3/#selectors"

taylorwood

Google Redirect (Beta)

Google has a https://www.google.com/url?q= endpoint that redirects to q, and it turns out you can nest these recursively and it'll 302 redirect you to each one in succession.

So here's the the most inefficient link to Google that will fit in a Tweet:

https://www.google.com/url?q=https%3A%2F%2Fwww.google.com%2Furl%3Fq%3Dhttps%253A%252F%252Fwww.google.com%252Furl%253Fq%253Dhttps%25253A%25252F%25252Fwww.google.com%25252Furl%25253Fq%25253Dhttps%2525253A%2525252F%2525252Fwww.google.com

Here's some Clojure I used to make the link:

taylorwood

What happened?

This compilation error was generated by a Scala Slick query that's essentially a SQL SELECT with two JOINs and a GROUP BY:

slick.SlickTreeException: Cannot convert node to SQL Comprehension
GroupBy t3 : Vector[(t3<(Option[String'], Option[String'])>, Vector[t4<{s5: Option[scala.math.BigDecimal'], s6: SOption[OptionDisc/Int], s7: Option[String'], s8: SOption[OptionDisc/Int], s9: Option[String']}>])]
  from s2: Bind : Vector[t4<{s5: Option[scala.math.BigDecimal'], s6: SOption[OptionDisc/Int], s7: Option[String'], s8: SOption[OptionDisc/Int], s9: Option[String']}>]
    from s10: Filter s11 : Vector[t12<{s13: String', s14: String', s15: String', s16: String', s17: String', s18: Option[String'], s19: Int', s20: Option[String'], s21: String', s22: scala.math.BigDecimal', s23: String', s24: String', s25: String', s26: String', s27: String', s28: Boolean', s29: scala.math.BigDecimal', s30: String', s31: String', s32: Boolean', s33: Option[String'], s34: String', s35: Option[String'], s36:

taylorwood

(defn zip
  "Returns a transducer that zips cs with inputs."
  [& cs]
  (fn [rf]
    (let [cs (volatile! cs)]
      (fn
        ([] (rf))
        ([result] (rf result))
        ([result item]
         (if (every? seq @cs)

taylorwood

// A sequence of integers is defined as F(N) = F(N-1) * F(N-2),
// with F(0) = 1 and F(1) = 2. 
// Write a function which, given N, prints N and F(N)
// f(2) = F(2-1) * F(2-2) = F(1) * F(0) = 2 * 1 = 2
// f(3) = f(3-1) * f(3-2) = f(2) * f(1) = 2 * 2 = 4
// f(4) = f(4-1) * f(4-2) = f(3) * f(2) = 4 * 2 = 8
// f(5) = f(5-1) * f(5-2) = f(4) * f(3) = 8 * 4 = 32
// f(6) = f(6-1) * f(6-2) = f(5) * f(4) = 32 * 8 = 256

// recursive

taylorwood

open System

// Data types //

/// Describes an Address, its physical location, and the times it will be occupied.
[<StructuredFormatDisplay("{Name}")>]
type Address = {
    Name: string
    Street: string
    City: string

taylorwood

(ns playground.test
  (:require [clojure.spec.alpha :as s]
            [clojure.spec.gen.alpha :as sgen]
            [clojure.spec.test.alpha :as stest]
            [clojure.string :as cs]
            [clojure.walk :as walk]))

(def op-keys #{:and :or})

(s/def ::expression