Skip to content

Instantly share code, notes, and snippets.

Avatar
💭
married

Vlad Patryshev vpatryshev

💭
married
View GitHub Profile
@vpatryshev
vpatryshev / RE.scala
Created Sep 24, 2012
regexp from Beautiful Code, in tongues
View RE.scala
case class Ch(c: Char) { def ~=(x: Char) = c == '.' || c == x }
class RE(val regexp: String) {
def skip(n: Int) = RE(regexp.substring(n))
implicit def token(c: Char) = Ch(c)
def c0 = Ch(regexp(0))
def c1 = regexp(1)
def ~=(text: String): Boolean = {
@vpatryshev
vpatryshev / ArrayListToFunctor
Last active Dec 14, 2015
an example how java.util.ArrayList can be turned into a functor and get a functor's map() method.
View ArrayListToFunctor
/**
* This trait (typeclass) defines one operation for a parametrized type F
* the operation is known as fmap in Haskell, f1 in internal categories.
*
* For each pair of arbitrary types X, Y and an arbitrary function:X=>Y,
* it should provide a function F[X]=>F[Y].
* Providing means that the implementation depends on a specific type F
* E.g. given F = List, and a function f(n: Int): String = "{{" + n + "}}",
* we should have a function List[Int]=>List[String] that wraps elements in double braces.
*
@vpatryshev
vpatryshev / HtmlPropsExtraction.scala
Last active Dec 21, 2015
sample code for html data extraction
View HtmlPropsExtraction.scala
// we already have a bunch of patient properties on one tab (in props1); now get another bunch from another tab
// we click it and wait for the element to show up; then:
val props2 = extractProperties("div#ctl00_ContentPlaceHolder1_Details_Container2") map (_.trimPrefixes)
// trimming prefixes means we do not care about all the additional keys, but just a variety of values
// now let's blend the two sets together; <*> will produce either Good((p1,p2)) or Bad(errors1 ++ errors2)
val propsOpt: Result[(Props, Props)] = props1 <*> props2
// then we want to merge together two sets of patient properties; that's what we do in map
val patientData = propsOpt map ((xy:(Props, Props)) => (xy._1 ++ xy._2))
debug(s"Got patient data\n $patientData")
View gist:6531769
def spendNotMoreThan[T](time: Duration) = new {
def on(op: => Result[T]): Result[T] = {
var res:Result[T] = Empty
var done = new AtomicBoolean(false)
val nanos = time.toNanos
val upto = System.nanoTime + nanos
val worker = new Thread {
override def run {
res = op
done.set(true)
View gist:7076235
def downloadPDF(url: String): Result[(File, String)] = {
loadPage(url) andThen
waitForSelector("div.textLayer") andThen
runJS("return extractPdfContent()") andThen {
Thread.sleep(2000) // give browser a chance
val extracted = runJS("return intBuf2hex(extractedPdf)") map (_.toString)
val pdf = extracted flatMap
(_.decodeHex #> File.createTempFile("download", ".pdf"))
val html = runJS("return _$('div.textLayer').innerHTML") map (_.toString)
@vpatryshev
vpatryshev / ZFC in Java
Created Nov 29, 2013
Wrote this code in July 2008, implementing ZFC set theory in Java. Kind of funny; it worked.
View ZFC in Java
import java.util.List;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Arrays;
import java.util.Map;
import java.util.IdentityHashMap;
import java.util.LinkedList;
import java.util.SortedSet;
import java.util.TreeSet;
View gist:5b3ace3c48cbd25c7562
### Keybase proof
I hereby claim:
* I am vpatryshev on github.
* I am vpatryshev (https://keybase.io/vpatryshev) on keybase.
* I have a public key whose fingerprint is F7CC C6E9 59DF 55AF 2BE7 676B 31F4 2673 9622 4C88
To claim this, I am signing this object:
@vpatryshev
vpatryshev / package.scala
Created Dec 16, 2015 — forked from zraffer/package.scala
a few operations with functors
View package.scala
package object types {
import scala.language.reflectiveCalls
import scala.language.higherKinds
// quantifiers aka (co)ends
type Forall[+F[_]] = { def apply[X]: F[X] }
type Exists[+F[_]] = F[_]
// basic categorical notions
@vpatryshev
vpatryshev / binary tree inorder
Created Apr 27, 2016
implementation of inorder scan of a binary tree
View binary tree inorder
case class BT[T](left: Option[BT[T]], value: T, right: Option[BT[T]]);
def inorder[T](t:BT[T], out: T=>Unit): Unit = {
val stack: mutable.Stack[(Boolean, BT[T])] = new mutable.Stack[(Boolean, BT[T])]()
def p(n: BT[T]) = stack.push((false, n))
p(t)
while (!stack.isEmpty) {
(stack.pop() match {
case (true, top) =>
out(top.value)
@vpatryshev
vpatryshev / EnvHacker.scala
Last active Aug 4, 2021 — forked from jaytaylor/EnvHacker.scala
Setting environment variables in Scala JVM
View EnvHacker.scala
import java.util.{Collections, Map => JavaMap}
import scala.collection.JavaConverters._
trait EnvHacker {
/**
* Portable method for setting env vars on both *nix and Windows.
* @see http://stackoverflow.com/a/7201825/293064
*/
def setEnv(newEnv: Map[String, String]): Unit = {
try {