feat(build): allow multiple binaries

I gave in because I wanted to use yaml-to-dhall, so this implements
copying multiple binaries.

build.nix

@@ -1,6 +1,6 @@
 { pkgs, release }:
 
-{ simpleName, binName, attrName }:
+{ simpleName, binNames, attrName }:
 
 let
   release = import ./release.nix;
@@ -23,9 +23,22 @@ pkgs.stdenv.mkDerivation rec {
 
   installPhase = ''
     mkdir -p $out/bin
-    binPath="$out/bin/${binName}"
-    install -D -m555 -T "${binName}" "$binPath"
-    rm "${binName}"
+
+    ${pkgs.lib.concatMapStringsSep "\n" (binName: ''
+        binPath="$out/bin/${binName}"
+        install -D -m555 -T "${binName}" "$binPath"
+        rm "${binName}"
+
+        "$binPath" --bash-completion-script "$binPath" > "${binName}.bash"
+        installShellCompletion --bash "${binName}.bash"
+        rm "${binName}.bash"
+        "$binPath" --zsh-completion-script "$binPath" > "${binName}.zsh"
+        installShellCompletion --zsh "${binName}.zsh"
+        rm "${binName}.zsh"
+        "$binPath" --fish-completion-script "$binPath" > "${binName}.fish"
+        installShellCompletion --fish "${binName}.fish"
+        rm "${binName}.fish"
+      '') binNames}
 
     # check that we didn’t forget any files (maybe a new binary was added)
     if [ ! -z "$(${pkgs.lr}/bin/lr -1 -t 'depth == 1' .)" ]; then
@@ -34,11 +47,5 @@ pkgs.stdenv.mkDerivation rec {
       exit 1
     fi
 
-    "$binPath" --bash-completion-script "$binPath" > "${binName}.bash"
-    installShellCompletion --bash "${binName}.bash"
-    "$binPath" --zsh-completion-script "$binPath" > "${binName}.zsh"
-    installShellCompletion --zsh "${binName}.zsh"
-    "$binPath" --fish-completion-script "$binPath" > "${binName}.fish"
-    installShellCompletion --fish "${binName}.fish"
   '';
 }

dhall-bash-simple.nix

@@ -2,6 +2,6 @@
 
 import ./build.nix { inherit pkgs; release = import ./release.nix; } {
   simpleName = "dhall-bash-simple";
-  binName = "dhall-to-bash";
+  binNames = [ "dhall-to-bash" ];
   attrName = "dhall-bash";
 }

dhall-lsp-simple.nix

@@ -2,6 +2,6 @@
 
 import ./build.nix { inherit pkgs; release = import ./release.nix; } {
   simpleName = "dhall-lsp-simple";
-  binName = "dhall-lsp-server";
+  binNames = [ "dhall-lsp-server" ];
   attrName = "dhall-lsp-server";
 }

dhall-nix-simple.nix

@@ -2,6 +2,6 @@
 
 import ./build.nix { inherit pkgs; release = import ./release.nix; } {
   simpleName = "dhall-nix-simple";
-  binName = "dhall-to-nix";
+  binNames = [ "dhall-to-nix" ];
   attrName = "dhall-nix";
 }

dhall-simple.nix

@@ -2,6 +2,6 @@
 
 import ./build.nix { inherit pkgs; release = import ./release.nix; } {
   simpleName = "dhall-simple";
-  binName = "dhall";
+  binNames = [ "dhall" ];
   attrName = "dhall";
 }

dhall-yaml-simple.nix

@@ -2,6 +2,6 @@
 
 import ./build.nix { inherit pkgs; release = import ./release.nix; } {
   simpleName = "dhall-yaml-simple";
-  binName = "dhall-to-yaml-ng";
+  binNames = [ "dhall-to-yaml-ng" "yaml-to-dhall" ];
   attrName = "dhall-yaml";
 }