{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE NoMonomorphismRestriction #-}
{-# OPTIONS_GHC -Wno-missing-signatures #-}

module Examples.Ex01 where

import Network.URI.Slug as URI
import Relude
import Symantic.Classes (ProductFunctor (..), SumFunctor (..), adt)

import Webc

-- | A convenient data-type to avoid using 'Either's and Tuples.
data Site
  = Index
  | About
  | Contact URI.Slug
  | Post [URI.Slug]
  deriving (Eq, Show, Generic)

{- | Polymorphic expression describing the website,
to be instantiated to the various interpreters.
NoMonomorphismRestriction is used to avoid specifying manually
the inferred symantic classes.
-}
site =
  -- site :: IsoFunctor repr => SumFunctor repr => Slugable repr => repr Site
  -- Using Generic, 'adt' derives (Iso{a2b, b2a} <%>)
  -- from the 'Site' algebraic data-type.
  adt @Site $
    literalSlug "index.html"
      <+> literalSlug "about.html"
      <+> captureSlug "user" <. literalSlug "contact.html"
      <+> "post" </> many0 (captureSlug "dir")