Elm: automate packaging with elm2nix

- rewrite documentation
- automate whole process into update.sh
- remove all legacy snippets

doc/package-notes.xml

@@ -307,23 +307,19 @@ packageOverrides = pkgs: {
 </screen>
   </para>
  </section>
+
  <section xml:id="sec-elm">
   <title>Elm</title>
 
   <para>
-   The Nix expressions for Elm reside in
-   <filename>pkgs/development/compilers/elm</filename>. They are generated
-   automatically by <command>update-elm.rb</command> script. One should specify
-   versions of Elm packages inside the script, clear the
-   <filename>packages</filename> directory and run the script from inside it.
-   <literal>elm-reactor</literal> is special because it also has Elm package
-   dependencies. The process is not automated very much for now -- you should
-   get the <literal>elm-reactor</literal> source tree (e.g. with
-   <command>nix-shell</command>) and run <command>elm2nix.rb</command> inside
-   it. Place the resulting <filename>package.nix</filename> file into
-   <filename>packages/elm-reactor-elm.nix</filename>.
+   To update Elm compiler, see <filename>nixpkgs/pkgs/development/compilers/elm/README.md</filename>.
+  </para>
+
+  <para>
+   To package Elm applications, <link xlink:href="https://github.com/hercules-ci/elm2nix#elm2nix">read about elm2nix</link>.
   </para>
  </section>
+
  <section xml:id="sec-shell-helpers">
   <title>Interactive shell helpers</title>
 

pkgs/development/compilers/elm/README.md

@@ -0,0 +1,24 @@
+# To update Elm:
+
+Modify revision in ./update.sh and run it
+
+# Notes about the build process:
+
+The elm binary embeds a piece of pre-compiled elm code, used by 'elm
+reactor'. This means that the build process for 'elm' effectively
+executes 'elm make'. that in turn expects to retrieve the elm
+dependencies of that code (elm/core, etc.) from
+package.elm-lang.org, as well as a cached bit of metadata
+(versions.dat).
+
+The makeDotElm function lets us retrieve these dependencies in the
+standard nix way. we have to copy them in (rather than symlink) and
+make them writable because the elm compiler writes other .dat files
+alongside the source code. versions.dat was produced during an
+impure build of this same code; the build complains that it can't
+update this cache, but continues past that warning.
+
+Finally, we set ELM_HOME to point to these pre-fetched artifacts so
+that the default of ~/.elm isn't used.
+
+More: https://blog.hercules-ci.com/elm/2019/01/03/elm2nix-0.1/

pkgs/development/compilers/elm/default.nix

@@ -2,54 +2,6 @@
 , haskell, nodejs
 , fetchurl, fetchpatch, makeWrapper, git }:
 
-# To update:
-
-# 1) Modify ./update.sh and run it
-
-# 2) to generate versions.dat:
-# 2.1) git clone https://github.com/elm/compiler.git
-# 2.2) cd compiler
-# 2.3) cabal2nix --shell . | sed 's/"default",/"ghc822",/' > shell.nix
-# 2.4) nix-shell
-# 2.5) mkdir .elm
-# 2.6) export ELM_HOME=$(pwd)/.elm
-# 2.7) cabal build
-# 2.8) cp .elm/0.19.0/package/versions.dat ...
-
-# 3) generate a template for elm-elm.nix with:
-# (
-#   echo "{";
-#   jq '.dependencies | .direct, .indirect | to_entries | .[] | { (.key) : { version : .value, sha256:  "" } } ' \
-#   < ui/browser/elm.json \
-#   | sed 's/:/ =/' \
-#   | sed 's/^[{}]//' \
-#   | sed -E 's/(["}]),?$/\1;/' \
-#   | sed -E 's/"(version|sha256)"/\1/' \
-#   | grep -v '^$';
-#   echo "}"
-# )
-#
-# ... then fill in the sha256s
-
-# Notes:
-
-# the elm binary embeds a piece of pre-compiled elm code, used by 'elm
-# reactor'. this means that the build process for 'elm' effectively
-# executes 'elm make'. that in turn expects to retrieve the elm
-# dependencies of that code (elm/core, etc.) from
-# package.elm-lang.org, as well as a cached bit of metadata
-# (versions.dat).
-
-# the makeDotElm function lets us retrieve these dependencies in the
-# standard nix way. we have to copy them in (rather than symlink) and
-# make them writable because the elm compiler writes other .dat files
-# alongside the source code. versions.dat was produced during an
-# impure build of this same code; the build complains that it can't
-# update this cache, but continues past that warning.
-
-# finally, we set ELM_HOME to point to these pre-fetched artifacts so
-# that the default of ~/.elm isn't used.
-
 let
   fetchElmDeps = import ./fetchElmDeps.nix { inherit stdenv lib fetchurl; };
   hsPkgs = haskell.packages.ghc822.override {
@@ -58,8 +10,8 @@ let
             elm = overrideCabal (self.callPackage ./packages/elm.nix { }) (drv: {
               # sadly with parallelism most of the time breaks compilation
               enableParallelBuilding = false;
-              preConfigure = fetchElmDeps {
-                elmPackages = (import ./packages/elm-elm.nix);
+              preConfigure = self.fetchElmDeps {
+                elmPackages = (import ./packages/elm-srcs.nix);
                 versionsDat = ./versions.dat;
               };
               buildTools = drv.buildTools or [] ++ [ makeWrapper ];
@@ -75,8 +27,6 @@ let
               '';
             });
 
-
-
             /*
             The elm-format expression is updated via a script in the https://github.com/avh4/elm-format repo:
             `pacakge/nix/build.sh`

pkgs/development/compilers/elm/elm2nix.rb

@@ -1,26 +0,0 @@
-#!/usr/bin/env ruby
-
-require 'json'
-
-system("elm-package install -y")
-depsSrc = JSON.parse(File.read("elm-stuff/exact-dependencies.json"))
-deps = Hash[ depsSrc.map { |pkg, ver|
-  url = "https://github.com/#{pkg}/archive/#{ver}.tar.gz"
-  sha256 = `nix-prefetch-url #{url}`
-
-  [ pkg, { version: ver,
-           sha256: sha256.strip
-         }
-  ]
-} ]
-
-File.open("package.nix", 'w') do |file|
-  file.puts "{"
-    for pkg, info in deps
-      file.puts "  \"#{pkg}\" = {"
-      file.puts "    version = \"#{info[:version]}\";"
-      file.puts "    sha256 = \"#{info[:sha256]}\";"
-      file.puts "  };"
-    end
-  file.puts "}"
-end

pkgs/development/compilers/elm/packages/elm-elm.nix

@@ -1,50 +0,0 @@
-{
-  "elm/browser" = {
-    version = "1.0.0";
-    sha256 = "1apmvyax93nvmagwj00y16zx10kfv640cxpi64xgqbgy7d2wphy4";
-  };
-  "elm/core" = {
-    version = "1.0.0";
-    sha256 = "10kr86h4v5h4p0586q406a5wbl8xvr1jyrf6097zp2wb8sv21ylw";
-  };
-  "elm/html" = {
-    version = "1.0.0";
-    sha256 = "1n3gpzmpqqdsldys4ipgyl1zacn0kbpc3g4v3hdpiyfjlgh8bf3k";
-  };
-  "elm/http" = {
-    version = "1.0.0";
-    sha256 = "1igmm89ialzrjib1j8xagkxalq1x2gj4l0hfxcd66mpwmvg7psl8";
-  };
-  "elm/json" = {
-    version = "1.0.0";
-    sha256 = "1g0hafkqf2q633r7ir9wxpb1lnlzskhpsyi0h5bkzj0gl072zfnb";
-  };
-  "elm/project-metadata-utils" = {
-    version = "1.0.0";
-    sha256 = "1d4rd4grrnbdvj9gf00h7dr6hbkjzawgkzpizfrkp1z1pyr3mvq9";
-  };
-  "elm/svg" = {
-    version = "1.0.0";
-    sha256 = "08x0v8p9wm699jjmsnbq69pxv3jh60j4f6fg7y6hyr7xxj85y390";
-  };
-  "elm-explorations/markdown" = {
-    version = "1.0.0";
-    sha256 = "0k3110ixa4wwf3vkkdplagwah9ypr965qxr1y147rnsc1xsxmr6y";
-  };
-  "elm/parser" = {
-    version = "1.0.0";
-    sha256 = "0k4zlq30lrvawqvzwbvsl0hrmwf9s832mb41z7fdspm4549dj7wc";
-  };
-  "elm/time" = {
-    version = "1.0.0";
-    sha256 = "0vch7i86vn0x8b850w1p69vplll1bnbkp8s383z7pinyg94cm2z1";
-  };
-  "elm/url" = {
-    version = "1.0.0";
-    sha256 = "0av8x5syid40sgpl5vd7pry2rq0q4pga28b4yykn9gd9v12rs3l4";
-  };
-  "elm/virtual-dom" = {
-    version = "1.0.0";
-    sha256 = "0hm8g92h7z39km325dlnhk8n00nlyjkqp3r3jppr37k2k13md6aq";
-  };
-}

pkgs/development/compilers/elm/packages/elm-srcs.nix

@@ -0,0 +1,62 @@
+{
+
+      "elm-explorations/markdown" = {
+        sha256 = "0k3110ixa4wwf3vkkdplagwah9ypr965qxr1y147rnsc1xsxmr6y";
+        version = "1.0.0";
+      };
+
+      "elm/json" = {
+        sha256 = "1g0hafkqf2q633r7ir9wxpb1lnlzskhpsyi0h5bkzj0gl072zfnb";
+        version = "1.0.0";
+      };
+
+      "elm/html" = {
+        sha256 = "1n3gpzmpqqdsldys4ipgyl1zacn0kbpc3g4v3hdpiyfjlgh8bf3k";
+        version = "1.0.0";
+      };
+
+      "elm/svg" = {
+        sha256 = "08x0v8p9wm699jjmsnbq69pxv3jh60j4f6fg7y6hyr7xxj85y390";
+        version = "1.0.0";
+      };
+
+      "elm/project-metadata-utils" = {
+        sha256 = "1d4rd4grrnbdvj9gf00h7dr6hbkjzawgkzpizfrkp1z1pyr3mvq9";
+        version = "1.0.0";
+      };
+
+      "elm/browser" = {
+        sha256 = "1apmvyax93nvmagwj00y16zx10kfv640cxpi64xgqbgy7d2wphy4";
+        version = "1.0.0";
+      };
+
+      "elm/core" = {
+        sha256 = "10kr86h4v5h4p0586q406a5wbl8xvr1jyrf6097zp2wb8sv21ylw";
+        version = "1.0.0";
+      };
+
+      "elm/http" = {
+        sha256 = "1igmm89ialzrjib1j8xagkxalq1x2gj4l0hfxcd66mpwmvg7psl8";
+        version = "1.0.0";
+      };
+
+      "elm/parser" = {
+        sha256 = "0k4zlq30lrvawqvzwbvsl0hrmwf9s832mb41z7fdspm4549dj7wc";
+        version = "1.0.0";
+      };
+
+      "elm/url" = {
+        sha256 = "0av8x5syid40sgpl5vd7pry2rq0q4pga28b4yykn9gd9v12rs3l4";
+        version = "1.0.0";
+      };
+
+      "elm/time" = {
+        sha256 = "0vch7i86vn0x8b850w1p69vplll1bnbkp8s383z7pinyg94cm2z1";
+        version = "1.0.0";
+      };
+
+      "elm/virtual-dom" = {
+        sha256 = "0hm8g92h7z39km325dlnhk8n00nlyjkqp3r3jppr37k2k13md6aq";
+        version = "1.0.0";
+      };
+}

pkgs/development/compilers/elm/packages/elm.nix

@@ -13,6 +13,7 @@ mkDerivation {
     url = "https://github.com/elm/compiler";
     sha256 = "13jks6c6i80z71mjjfg46ri570g5ini0k3xw3857v6z66zcl56x4";
     rev = "d5cbc41aac23da463236bbc250933d037da4055a";
+    fetchSubmodules = true;
   };
   isLibrary = false;
   isExecutable = true;

pkgs/development/compilers/elm/update.sh

@@ -1 +1,8 @@
-cabal2nix https://github.com/elm/compiler --revision  32059a289d27e303fa1665e9ada0a52eb688f302 > packages/elm.nix
+#!/usr/bin/env nix-shell
+#!nix-shell -p cabal2nix elm2nix -i bash ../../..
+
+cabal2nix https://github.com/elm/compiler --revision d5cbc41aac23da463236bbc250933d037da4055a > packages/elm.nix
+elm2nix snapshot > versions.dat
+pushd "$(nix-build -A elmPackages.elm.src --no-out-link ../../../..)/ui/browser"
+  elm2nix convert > $OLDPWD/packages/elm-srcs.nix
+popd