anchor.diff:  
     jsonFile = name: val: (formats.json { }).generate name val;
   
  -  # implementation of the fetching of repo information from github
  -  fetchImpl = passArgs "fetchImpl-with-args" {
  +  # implementation of the updater
  +  updateImpl = passArgs "updateImpl-with-args" {
         binaries = {
           curl = "${curl}/bin/curl";
           nix-prefetch-git = "${nix-prefetch-git}/bin/nix-prefetch-git";
  
positive.code:           })
            allGrammars)
      }
      ${fetchImpl} print-all-grammars-nix-file "$(< ${
          jsonFile "all-grammars.json" {
            allGrammars =
              (lib.mapAttrsToList
  
negative.code:       ${xe}/bin/xe -F -j5 ${script} {}
    '';
  
    # The output directory in the current source tree.
    # This will depend on your local environment, but that is intentional.
    outputDir = "${toString ./.}/grammars";
  
    update-all-grammars = writeShellScript "update-all-grammars.sh" ''
      set -euo pipefail
      echo "fetching list of grammars" 1>&2
      treeSitterRepos=$(${updateImpl} fetch-orga-latest-repos '{"orga": "tree-sitter"}')
      echo "checking the tree-sitter repo list against the grammars we know" 1>&2
      printf '%s' "$treeSitterRepos" | ${updateImpl} check-tree-sitter-repos '{}'
      echo "writing files to ${outputDir}" 1>&2
      mkdir -p "${outputDir}"
      ${forEachParallel
          "repos-to-fetch"
          (writeShellScript "fetch-repo" ''
              ${updateImpl} fetch-repo "$1"
          '')
          (lib.mapAttrsToList
            (nixRepoAttrName: attrs: attrs // {
  