ssanj

query {
  repository(owner: "typelevel", name: "cats") {
    refs(last: 5, refPrefix: "refs/tags/") {
      nodes {
        id
        name 
        target {
          ... on Tag{
            id
            message

ssanj

module MyParser where

import Text.Read (readMaybe)

newtype Parser a = Parser { runParser :: String ->  Either String (a, String) }

parseChar :: Char -> Parser Char
parseChar char =
  Parser $ \input ->
    case input of

ssanj

{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE QuasiQuotes         #-}
{-# LANGUAGE ScopedTypeVariables #-}

module ExampleErrorSpec where

import           Test.Hspec
import           Test.Hspec.Wai

spec :: Spec

ssanj

What is a Pull, taken from a Gitter thread.

All comments are by Fabio Labella @SystemFw unless specified.

[1] https://gitter.im/functional-streams-for-scala/fs2?at=5acb7b81109bb04332a39a41

What is a Pull

ssanj

What is a Pull, taken from a Gitter thread.

All comments are by Fabio Labella @SystemFw unless specified.

[1] https://gitter.im/functional-streams-for-scala/fs2?at=5acb7b81109bb04332a39a41

What is a Pull

ssanj

import fs2.Stream
import fs2.Pipe
import fs2.Chunk
import fs2.Pull
import cats.effect.IO
import scala.language.higherKinds

//implementing scan from https://fs2.io/guide.html#exercises-stream-transforming
//Stream.range(1,10).scan(0)(_ + _).toList // running sum
// res38: List[Int] = List(0, 1, 3, 6, 10, 15, 21, 28, 36, 45)

ssanj

//I'm trying to implement `intersperse` from : https://fs2.io/guide.html#exercises-stream-transforming

import fs2.Stream
import fs2.Pipe
import fs2.Chunk
import fs2.Pull
import cats.effect.IO
import scala.language.higherKinds

object Intersperse {

ssanj

count :: Int -> IO Int
count it
 | it <= 0   = pure 0
 | otherwise = 
    do 
      n <- count (it - 1)
      pure (n + 1)

ssanj

scala> trait A { val a: String = "this is A" }
defined trait A

scala> trait B { val b: String = "this is B" }
defined trait B

scala> trait C { val c: String = "this is C" }
defined trait C

scala> val abc = new A with B with C

ssanj

type ErrorOr[A] = Either[String, A]

def errors(error: String): () => ErrorOr[Int] = () => {
  println(s"running $error")
  Left(error)
}

scala> val item1 = errors("error1")
item1: () => ErrorOr[Int] = $$Lambda$4361/1034150118@23f4a773