Initial commit

flake.nix

@@ -0,0 +1,13 @@
+{
+  description = "Nix-to-XML converter.";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-22.05";
+    utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, utils }: {
+    lib.toXML = import ./to-xml.nix { inherit (nixpkgs) lib; };
+    overlay = final: prev: { lib = prev.lib // { toXML = self.lib.toXML; }; };
+  };
+}

to-formatted-xml.nix

@@ -0,0 +1,5 @@
+{ lib, toXMLFile, ... }:
+
+content:
+let xmlFile = toXMLFile "formatted-xml" content;
+in lib.readFile xmlFile

to-xml-file.nix

@@ -0,0 +1,10 @@
+{ lib, pkgs, toXML, ... }:
+
+name: content:
+let preformatXML = pkgs.writeText "${name}-preformat.xml" (toXML content);
+in pkgs.stdenv.mkDerivation {
+  name = "${name}.xml";
+  phases = [ "installPhase" ];
+  buildInputs = with pkgs; [ xmlformat ];
+  installPhase = "xmlformat ${preformatXML} > $out";
+}

to-xml.nix

@@ -0,0 +1,33 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  isEmpty = lst: (length lst) == 0;
+  isEmptyAttrs = attrs: (length (attrNames attrs)) == 0;
+  renderAttr = name: value: ''${name}="${value}"'';
+  renderAttrs = attrs:
+    if (isEmptyAttrs attrs) then
+      ""
+    else
+      " " + concatStringsSep " " (mapAttrsToList renderAttr attrs);
+  renderTag = tag: attrs: body: "<${tag}${renderAttrs attrs}>${body}</${tag}>";
+  # renderLoneTag = tag: attrs: "<${tag}${renderAttrs attrs} />";
+  toXML = { tag, attrs ? { }, children ? [ ] }:
+    let
+      renderElement = el: if isString el then el else toXML el;
+      body = concatStringsSep "" (map renderElement children);
+    in renderTag tag attrs body;
+
+  toXMLFile = name: content:
+    let preformatXML = pkgs.writeText "${name}-preformat.xml" (toXML content);
+    in pkgs.stdenv.mkDerivation {
+      name = "${name}.xml";
+      phases = [ "installPhase" ];
+      buildInputs = with pkgs; [ xmlformat ];
+      installPhase = "xmlformat ${preformatXML} > $out";
+    };
+
+  toFormattedXML = content:
+    let xmlFile = toXMLFile "formatted-xml" content;
+    in readFile xmlFile;
+in { inherit toXML toXMLFile toFormattedXML; }