skeleton of example

example/Example.idr

@@ -0,0 +1,7 @@
+module Example
+
+import TAP
+
+
+main : IO ()
+main = TAP.main !getTestOpts []

example/example.ipkg

@@ -0,0 +1,8 @@
+package tap-example
+depends = base, contrib, tap
+
+sourcedir = "."
+
+executable = tap-example
+main = Example
+modules = Example

flake.nix

@@ -7,8 +7,10 @@
   };
 
   outputs = { self, nixpkgs, idris2-pkgs, flake-utils }:
-    flake-utils.lib.eachSystem [ "x86_64-darwin" "x86_64-linux" "i686-linux" ]
+    let systems = with flake-utils.lib.system;
-      (system:
+          [ x86_64-darwin x86_64-linux i686-linux ];
+    in
+    flake-utils.lib.eachSystem systems (system:
       let
         pkgs = import nixpkgs {
           inherit system;
@@ -16,11 +18,19 @@
         };
         inherit (pkgs.idris2-pkgs._builders) idrisPackage devEnv;
 
+        packages = rec {
           tap = idrisPackage ./. { };
+          tap-example = idrisPackage ./example { extraPkgs = packages; };
+        };
+        devShells =
+          let mkDevShell = _: pkg:
+                pkgs.mkShell { buildInputs = [ (devEnv pkg) ]; };
+              shells = packages // (with packages; { example = tap-example; });
+          in builtins.mapAttrs mkDevShell shells;
       in {
-          defaultPackage = tap;
+        inherit packages devShells;
-          packages = { inherit tap; };
+        defaultPackage = packages.tap;
-          devShell = pkgs.mkShell { buildInputs = [ (devEnv tap) ]; };
+        devShell = devShells.tap;
       }
     );
 }