temp

index.html

@@ -4842,10 +4842,8 @@ Hello from your flake!</pre>
 <h4 id="_access_a_haskell_library_package_in_the_nixpkgs_repo_without_a_cabal_file_2">10.4.3. Access a Haskell library package in the nixpkgs repo (without a <code>.cabal</code> file)</h4>
 <div class="paragraph">
 <p>Occasionally you might want to run a short Haskell program that depends on a Haskell library,
-but you don&#8217;t want to bother writing a cabal file.</p>
-</div>
-<div class="paragraph">
-<p>Example: Access the <code>containers</code> package from the <code>haskellPackages</code> set in the nixpkgs repo.</p>
+but you don&#8217;t want to bother writing a cabal file.
+In this example, we will access the <code>containers</code> package from the <code>haskellPackages</code> set in the nixpkgs repo.</p>
 </div>
 <div class="listingblock">
 <div class="title">flake.nix</div>
@@ -5575,7 +5573,7 @@ Hello from your flake!</pre>
 </div>
 <div id="footer">
 <div id="footer-text">
-Last updated 2025-09-13 20:09:02 IST
+Last updated 2025-09-13 20:11:05 IST
 </div>
 </div>
 </body>

source/recipes/devshell/haskell-flake/flake.nix

@@ -10,6 +10,7 @@
     pandoc-columns.url = "/home/amy/github/pandoc-columns";
     pandoc-query.url = "/home/amy/codeberg/pandoc-query";
   };
+
   outputs = inputs@{ self, nixpkgs, flake-parts, pandoc-linear-table, pandoc-logic-proof, pandoc-columns, pandoc-query, ... }:
     flake-parts.lib.mkFlake { inherit inputs; } {
       systems = nixpkgs.lib.systems.flakeExposed;

source/recipes/devshell/haskell-flake/main.adoc0

@@ -1,8 +1,21 @@
-= Access to a Haskell package on your local computer
+= Access to a Haskell package defined in a flake
 
-Ex: Access three Haskell packages
+////
+$ mkdir tempwork
+$ cd tempwork
+$ cp ../flake.nix .
+$ git add flake.nix
+$ nix develop
+$ git add flake.lock
+$ git commit -a -m temp
+////
+
+
+In this example we will access three Haskell packages
 (`pandoc-linear-table`, `pandoc-logic-proof`, and `pandoc-columns`)
-that are on my hard drive.
+that are defined as flakes on my hard drive.
+We are using `haskell-flake`, so the development environment is
+set up automatically; no need to define `devShells`.
 
 [source,nix,linenums]
 .flake.nix
@@ -10,4 +23,15 @@ that are on my hard drive.
 include::flake.nix[]
 ....
 
-// TODO Add demo
+Here's a demonstration using the shell.
+
+....
+$# ../../../../../start-shell nix develop <<EOL
+$ cabal info pandoc-columns
+$# EOL
+....
+
+////
+Good adoc0 scripts clean up after themselves.
+$ cd .. ; rm -rf tempwork # clean up
+////

source/recipes/devshell/haskell-pkg/main.adoc0

@@ -4,7 +4,7 @@
 $ mkdir tempwork
 $ cd tempwork
 $ cp ../flake.nix ../Main.hs .
-$ git add flake.nix
+$ git add Main.hs flake.nix
 $ nix develop
 $ git add flake.lock
 $ git commit -a -m temp

source/recipes/devshell/haskell-pkg/tempwork/Main.hs

@@ -0,0 +1,11 @@
+import Data.Map
+
+m :: Map String Int
+m = fromList [("cats", 3), ("dogs", 2)]
+
+main :: IO ()
+main = do
+  let cats = findWithDefault 0 "cats" m
+  let dogs = findWithDefault 0 "dogs" m
+  let zebras = findWithDefault 0 "zebras" m
+  print $ "I have " ++ show cats ++ " cats, " ++ show dogs ++ " dogs, and " ++ show zebras ++ " zebras."