joshcough

April Talk 1: Austin Seipp
April Talk 2: ? (maybe lightning talks, or book someone else)

May Talk 1: Fere (François-René ÐVB Rideau)
May Talk 2: ? (maybe lightning talks, or book someone else)

June Talk 1: Maybe Nathan Howell (but possibly some other month, Ed needs to follow up)
June Talk 2 ?

Later:

joshcough

{-# LANGUAGE GADTs, ConstraintKinds, Rank2Types, ImplicitParams #-}

data Rec fields where
  Rec :: fields => Rec fields

infixr 1 ?
(?) :: Rec fields -> (fields => r) -> r
Rec ? e = e

record :: Rec (?a :: Int, ?b :: String)

joshcough

*ghci> g
Game {, [Josh rack: HXDOTQI score: 0id: 0] :| [[Nick rack: KGAITTE score: 0id: 1]], ______________________________________________
|3W|  |  |2L|  |  |  |3W|  |  |  |2L|  |  |3W|
|  |2W|  |  |  |3L|  |  |  |3L|  |  |  |2W|  |
|  |  |2W|  |  |  |2L|  |2L|  |  |  |2W|  |  |
|2L|  |  |2W|  |  |  |2L|  |  |  |2W|  |  |2L|
|  |  |  |  |2W|  |  |  |  |  |2W|  |  |  |  |
|  |3L|  |  |  |3L|  |  |  |3L|  |  |  |3L|  |
|  |  |2L|  |  |  |2L|  |2L|  |  |  |2L|  |  |
|3W|  |  |2L|  |  |  | *|  |  |  |2L|  |  |3W|

joshcough

$ stack ghci
*ghci> import Data.Aeson
*ghci> let g = unsafeNewGame [human "josh"]
*ghci> let g = unsafeNewGame [human "josh", human "nick"]
*ghci> g
Game {, [[josh rack: DOERUTO score: 0id: 0],[nick rack: ELIALIH score: 0id: 1]], ______________________________________________
|3W|  |  |2L|  |  |  |3W|  |  |  |2L|  |  |3W|
|  |2W|  |  |  |3L|  |  |  |3L|  |  |  |2W|  |
|  |  |2W|  |  |  |2L|  |2L|  |  |  |2W|  |  |
|2L|  |  |2W|  |  |  |2L|  |  |  |2W|  |  |2L|

joshcough

import scala.language.higherKinds
import scalaz.{Applicative, Traverse}

import scalaz.\/
import scalaz.std.list._
import scalaz.std.option._
import scalaz.syntax.either._
import scalaz.syntax.traverse._

object Mappy {

joshcough

//libraryDependencies += "org.scalaz" %% "scalaz-core" % "7.2.0"

import scala.language.higherKinds
import scalaz.{MonadState, MonadListen, MonadReader, MonadError, \/}
import scalaz.std.list._

// All I want to do in this code is invoke the eval function. That's it.
// This code compiles, so it's close, just needs the finishing touch.
object HowDoICallEval {

joshcough

Jack Cough

Guy Steele

Rod Johnson

Dick Wall

Jonas Boner

joshcough

Direct links to free Springer maths books (pdf versions)

duplicates = multiple editions

A Classical Introduction to Modern Number Theory,Kenneth IrelandMichael Rosen

A Classical Introduction to Modern Number Theory,Kenneth IrelandMichael Rosen

A Course in Arithmetic,Jean-Pierre Serre

joshcough

Let's say I want to look something up in an environment (like Map String Int or something, doesn't really matter). I start with Reader for the Env, and I use the ask function.

type Env = Map String Int

envLookup :: String -> Reader Env Int
envLookup key = (Maybe.fromMaybe (error "unbound var") . Map.lookup key) <$> ask

joshcough

  type R[A]       = Reader[Env, A]
  type Z[F[_], A] = WriterT[F, Output, A]
  type W[A]       = Z[R, A]

  def evalLocal(x: String, i: Int, exp: Exp): W[Int] = {
    WriterT[R,Output,Int](
      Reader[Env, (Output, Int)] { (env: Env) =>
        eval(exp).run.run(env + (x -> i))
      }
    )