| AbortDocumentVersionUpload | |
| AbortEnvironmentUpdate | |
| AbortMultipartUpload | |
| AbortVaultLock | |
| AcceptAccountMapping | |
| AcceptCertificateTransfer | |
| AcceptDelegate | |
| AcceptDirectConnectGatewayAssociationProposal | |
| AcceptFxPaymentCurrencyTermsAndConditions | |
| AcceptHandshake |
| import { log } from 'fp-ts/lib/Console' | |
| import { Type, URIS } from 'fp-ts/lib/HKT' | |
| import { none, Option, some } from 'fp-ts/lib/Option' | |
| import { randomInt } from 'fp-ts/lib/Random' | |
| import { fromIO, Task, task, URI as TaskURI } from 'fp-ts/lib/Task' | |
| import { createInterface } from 'readline' | |
| // | |
| // helpers | |
| // |
| package fpmax | |
| import scala.util.Try | |
| import scala.io.StdIn.readLine | |
| object App0 { | |
| def main: Unit = { | |
| println("What is your name?") | |
| val name = readLine() |
Miles Sabin recently opened a pull request fixing the infamous SI-2712. First off, this is remarkable and, if merged, will make everyone's life enormously easier. This is a bug that a lot of people hit often without even realizing it, and they just assume that either they did something wrong or the compiler is broken in some weird way. It is especially common for users of scalaz or cats.
But that's not what I wanted to write about. What I want to write about is the exact semantics of Miles's fix, because it does impose some very specific assumptions about the way that type constructors work, and understanding those assumptions is the key to getting the most of it his fix.
For starters, here is the sort of thing that SI-2712 affects:
def foo[F[_], A](fa: F[A]): String = fa.toString
| """ | |
| This is an extension of the technique first detailed here: | |
| http://sedimental.org/remap.html#add_common_keys | |
| In short, it calls remap on each container, back to front, using the accumulating | |
| previous values as the default for the current iteration. | |
| """ |
| import scala.language.experimental.macros | |
| import scala.reflect.macros.blackbox.Context | |
| trait Mappable[T] { | |
| def toMap(t: T): Map[String, Any] | |
| def fromMap(map: Map[String, Any]): T | |
| } | |
| object Mappable { | |
| public class UTF8 { | |
| public static void main(String[] args) { | |
| // See http://www.fileformat.info/info/unicode/char/1f4a9/index.htm | |
| final String poo = "A pile of poo: 💩."; | |
| System.out.println(poo); | |
| // Length of chars doesn't equals the "real" length, that is: the number of actual codepoints | |
| System.out.println(poo.length() + " vs " + poo.codePointCount(0, poo.length())); | |
| // Iterating over all chars |
| package controllers | |
| import play.api._ | |
| import play.api.mvc._ | |
| object Application extends Controller { | |
| def zip = Action { | |
| import play.api.libs.iteratee._ | |
| import java.util.zip._ |