Use heap-of-vars for rec attrsets, fix lazy function args

samples/attrset-nested-both.nix

@@ -0,0 +1 @@
+rec { a = 1; b = rec { c = d.foo; }; d = { foo = a; }; }.b.c

src/transformers/attribute-sets.js

@@ -5,6 +5,7 @@ const types = require("@babel/types");
 const template = require("@babel/template").default;
 const unpackExpression = require("./_unpack-expression");
 const NoChange = require("../astformer/actions/no-change");
+const printAst = require("../print-ast");
 
 // FIXME: Add expression parens!
 let tmplCallLazy = template(`
@@ -23,9 +24,23 @@ let tmplExtend = template(`(
 	$$jsNix$extend(this ?? {}, %%object%%)
 )`);
 
+let tmplScopeWrapper = template(`(
+	(() => {
+		%%bindings%%;
+
+		return %%object%%;
+	})()
+)`);
+
+// FIXME: Verify that this always works, and that we don't need `var` for hoisting!
+let tmplRecursiveBinding = template(`
+	const %%name%% = %%expression%%;
+`);
+
 function lazyEvaluationWrapper(args) {
 	let { recursive, ... rest } = args;
 
+	// printAst(rest.expression);
 	let wrapper = (recursive)
 		? tmplLazyWrapperRecursive
 		: tmplLazyWrapper;
@@ -68,23 +83,41 @@ module.exports = {
 				let isRecursive = node.recursive;
 				let hasDynamicBindings = node.bind.some((binding) => isDynamicBinding(binding));
 
+				let bindings = node.bind.map((binding) => {
+					assert(binding.attrpath.attr.length === 1); // Nested attributes should have been desugared by this point
+
+					return {
+						name: binding.attrpath.attr[0].name,
+						expression: lazyEvaluationWrapper({ recursive: isRecursive, expression: binding.expression })
+					};
+				});
+
 				if (hasDynamicBindings) {
 					throw new Error(`UNIMPLEMENTED: Dynamic bindings are not supported yet`); 
+				} else if (isRecursive) {
+					return unpackExpression(tmplScopeWrapper({
+						bindings: bindings.map(({ name, expression }) => {
+							return tmplRecursiveBinding({
+								name: name,
+								expression: expression
+							});
+						}),
+						object: types.objectExpression(bindings.map(({ name }) => {
+							return types.objectProperty(
+								types.stringLiteral(name),
+								types.identifier(name)
+							);
+						}))
+					}));
 				} else {
-					let object = types.objectExpression(node.bind.map((binding) => {
-						assert(binding.attrpath.attr.length === 1); // Nested attributes should have been desugared by this point
-						let name = binding.attrpath.attr[0].name;
-						let expression = binding.expression;
-
+					let object = types.objectExpression(bindings.map(({ name, expression }) => {
 						return types.objectProperty(
 							types.stringLiteral(name),
-							lazyEvaluationWrapper({ recursive: isRecursive, expression: expression })
+							// TODO: Remove the isRecursive distinction here once heap-of-vars works
+							expression
 						);
 					}));
 
-					// FIXME/MARKER: This is currently broken!
-					console.log({context: getContext("attributeSets_inRecursiveSet")});
-
 					// Only do prototypal inheritance for `this` if we're dealing with nested recursive attribute sets
 					if (isRecursive && getContext("attributeSets_inRecursiveSet") === true) {
 						return unpackExpression(tmplExtend({

src/transformers/functions.js

@@ -32,6 +32,11 @@ let tmplFunctionCall = template(`
 	(%%function%%(%%arg%%))
 `);
 
+// NOTE: Duplicated from `attribute-sets` for now
+let tmplLazyWrapper = template(`(
+	() => %%expression%%
+)`);
+
 function functionDefinition({ universal, formals, body }) {
 	let convertedFormals = asExpression(() => {
 		if (formals != null) {
@@ -101,7 +106,7 @@ module.exports = {
 				return unpackExpression(
 					tmplFunctionCall({
 						function: node.function,
-						arg: node.argument
+						arg: unpackExpression(tmplLazyWrapper({ expression: node.argument }))
 					})
 				);
 			});

src/transformers/index.js

@@ -47,7 +47,7 @@ let tmplObjectDynamicEntry = template(`
 `);
 
 let tmplIdentifierReference = template(`(
-	(this?.%%name%% ?? %%name%%)()
+	%%name%%()
 )`);
 
 function generateDynamicObject(bindings, recursive) {