Add most trivial example, Ex00_Hello.hs

docs/start/tutorial.md

@@ -9,20 +9,29 @@ Make sure that you have have followed [the previous section](start.md) in order
 ```haskell
 module Main where
 
-import qualified Ema
+import Ema
+import Generics.SOP qualified as SOP
+
+data Route = Route_Index
+  deriving stock (Show, Eq, Ord)
+deriveGeneric ''Route
+deriving anyclass instance IsRoute Route
+
+instance EmaSite Route where
+  siteOutput _enc _m Route_Index =
+    Ema.AssetGenerated Ema.Html "<b>Hello</b>, Ema"
 
 main :: IO ()
-main = do
-  let speaker :: Text = "Ema"
-  Ema.runEmaPure $ \_ ->
-    encodeUtf8 $ "<b>Hello</b>, from " <> speaker
+main = void $ Ema.runSite @Route ()
 ```
 
 This is the *minimum* amount of code necessary to run an Ema site. Notice that as you replace and save this file, your browser (which is at <http://locahost:9001>) will [hot reload](concepts/hot-reload.md) to display "Hello, Ema". Congratulations, you just created your first website! 
 
+TODO: change below.
+
 ## Expanding on Hello World
 
-Okay, but that's just *one* page. But we want to add a second page. And might as well add more content than "Hello, Ema". Let's do that next. The first step is define the [route](guide/routes.md) type that corresponds to our site's pages. Add the following:
+Okay, but that's just *one* page. But we want to add a second page. And we might as well add more content than "Hello, Ema". Let's do that next. The first step is define the [route](guide/routes.md) type that corresponds to our site's pages. Add the following:
 
 ```haskell
 data Route

ema.cabal

@@ -141,6 +141,7 @@ library
   if flag(with-examples)
     other-modules:
       Ema.Example.Common
+      Ema.Example.Ex00_Hello
       Ema.Example.Ex01_Basic
       Ema.Example.Ex02_Clock
       Ema.Example.Ex03_Store

src/Ema/Example/Ex00_Hello.hs

@@ -0,0 +1,20 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE TemplateHaskell #-}
+
+-- | Most trivial Ema program
+module Ema.Example.Ex00_Hello where
+
+import Ema
+import Generics.SOP.TH (deriveGeneric)
+
+data Route = Route_Index
+  deriving stock (Show, Eq, Ord)
+deriveGeneric ''Route
+deriving anyclass instance IsRoute Route
+
+instance EmaSite Route where
+  siteOutput _enc _m Route_Index =
+    Ema.AssetGenerated Ema.Html "<b>Hello</b>, Ema"
+
+main :: IO ()
+main = void $ Ema.runSite @Route ()

src/Ema/Example/Ex04_Multi.hs

@@ -9,6 +9,7 @@ module Ema.Example.Ex04_Multi where
 import Data.Generics.Sum.Any (AsAny (_As))
 import Ema
 import Ema.Example.Common (tailwindLayout)
+import Ema.Example.Ex00_Hello qualified as Ex00
 import Ema.Example.Ex01_Basic qualified as Ex01
 import Ema.Example.Ex02_Clock qualified as Ex02
 import Ema.Example.Ex03_Store qualified as Ex03
@@ -22,6 +23,7 @@ import Prelude hiding (Generic)
 
 data R
   = R_Index
+  | R_Hello Ex00.Route
   | R_Basic Ex01.Route
   | R_Clock Ex02.Route
   | R_Store Ex03.Route
@@ -48,6 +50,8 @@ instance EmaSite R where
     R_Index ->
       Ema.AssetGenerated Ema.Html $ renderIndex enc m
     -- TODO: Can all of these be generalized? (constructor with 1 encoder; delegate)
+    R_Hello r ->
+      siteOutput (innerRouteEncoder (_As @"R_Hello") enc) (innerModel m) r
     R_Basic r ->
       siteOutput (innerRouteEncoder (_As @"R_Basic") enc) (innerModel m) r
     R_Store r ->
@@ -61,6 +65,7 @@ renderIndex enc m@(I clockTime :* I _store :* Nil) =
     H.div ! A.class_ "container mx-auto text-center mt-8 p-2" $ do
       H.p "You can compose Ema sites. Here are three sites composed to produce one:"
       H.ul ! A.class_ "flex flex-col justify-center .items-center mt-4 space-y-4" $ do
+        H.li $ routeElem (R_Hello Ex00.Route_Index) "Ex00_Hello"
         H.li $ routeElem (R_Basic Ex01.Route_Index) "Ex01_Basic"
         H.li $ routeElem (R_Clock Ex02.Route_Index) "Ex02_Clock"
         H.li $ routeElem (R_Store Ex03.Route_Index) "Ex03_Store"