mkohlhaas

=================================================================================================
|                                      Mapping functions                                        |
=================================================================================================

                                   ------------------------
                                   | One mapping function |
                                   ------------------------

class Functor f where
  map :: ∀ a b. (a -> b) -> f a -> f b                             (Covariant)

mkohlhaas

module Ch15 where

import Prelude
import Data.Int       (even, odd)
import Data.Foldable  (class Foldable, foldl)
import Data.List      (List(..), (:))
import Data.String    (length)
import Effect         (Effect)
import Effect.Console (log)

mkohlhaas

module Ch17 where
( Age (..)
, FamilyAges(..)
, FamilyAgesRow
, Validation(..)
, Either(..)
, createFamilyAges
, test
) where

mkohlhaas

module Ch17Parser where

import Prelude
import Data.Either            (Either(..))
import Data.Maybe             (Maybe(..))
import Data.Tuple             (Tuple(..))
import Data.Array             as A
import Data.Unfoldable        as U
import Data.Traversable       (class Traversable, sequence)
import Data.Generic.Rep       (class Generic)

mkohlhaas

What is the Reader Monad Good For?

mkohlhaas

module Ch19 where

import Prelude
import Data.Generic.Rep  (class Generic)
import Data.Show.Generic (genericShow)
import Effect            (Effect)
import Effect.Console    (log)

-----------
-- Maybe --

mkohlhaas

module Ch19Parser where

import Prelude
import Data.Either            (Either(..))
import Data.Maybe             (Maybe(..))
import Data.Tuple             (Tuple(..))
import Data.Array             as A
import Data.Unfoldable        as U
import Data.Traversable       (class Traversable, sequence)
import Data.Generic.Rep       (class Generic)

mkohlhaas

module Ch19DateParser where

import Prelude
import Control.Alt (class Alt, (<|>))
import Data.Array (cons)
import Data.CodePoint.Unicode (isDecDigit, isAlpha)
import Data.Either (Either(..))
import Data.Generic.Rep (class Generic)
import Data.Int (fromString)
import Data.Maybe (Maybe(..), fromMaybe)

mkohlhaas

module Ch19SomeManyCombinators where

import Prelude
import Control.Alt (class Alt, (<|>))
import Control.Lazy (class Lazy, defer)
import Data.Array as A
import Data.CodePoint.Unicode (isDecDigit, isAlpha)
import Data.Either (Either(..))
import Data.Generic.Rep (class Generic)
import Data.Maybe (Maybe(..))

mkohlhaas

module Ch19RWS where

import Prelude
import Data.Tuple (Tuple(..))
import Effect (Effect)
import Effect.Console (log)

-- rewrite Reader, Writer and State data types which are monads for your own reference
-- you might want to comment out the code