Move reserved word mangling, implement conditionals, unary operations

src/mangle-name.js

@@ -5,20 +5,29 @@ const assert = require("assert");
 const acceptableFirstCharacters = /^[a-zA-Z_]$/;
 const acceptableSubsequentCharacters = /^[0-9a-zA-Z_]$/;
 
+const reservedWords = new Set([
+	"import",
+	"const",
+	"let",
+	"var"
+]);
+
 // This function deterministically and statelessly translates a name such that it is guaranteed to be valid in all identifier positions in JS.
 // TODO: This can probably be made more performant...
 
 function mangleCharacter(character) {
 	return (character === "$")
 		? "$$"
-		: `$${character.codePointAt(0)}`
+		: `$${character.codePointAt(0)}`;
 }
 
 module.exports = function mangleName(name) {
 	assert(name.length > 0);
 	
-	// FIXME: Tag an identifier of this type with an internal property instead
-	if (name.startsWith("$")) {
+	if (reservedWords.has(name)) {
+		return "$" + name;
+	} else if (name.startsWith("$")) {
+		// FIXME: Tag an identifier of this type with an internal property instead
 		return name;
 	} else {
 		let completedFirstCharacter = false;

src/prepare-ast.js

@@ -150,7 +150,7 @@ function convertNode(node) {
 		result.uri = node.text;
 	}
 
-	if (type === "binary_expression") {
+	if (type === "binary_expression" || type === "unary_expression") {
 		// Unpack the anonymous token
 		result.operator = result.operator.text;
 	}
@@ -201,12 +201,14 @@ function convertNode(node) {
 		inherited_attrs: "NixInheritAttributes",
 		attrs_inherited_from: "NixInheritAttributes", // FIXME: Gone?
 		binding: "NixBinding",
+		unary_expression: "NixUnaryOperation",
 		binary_expression: "NixBinaryOperation",
 		apply_expression: "NixFunctionCall",
 		select_expression: "NixAttributeSelection",
 		interpolation: "NixInterpolationExpression",
 		list_expression: "NixListLiteral",
 		with_expression: "NixWithExpression",
+		if_expression: "NixConditional",
 		// Function definitions
 		function_expression: "NixFunctionDefinition",
 		formals: "NixUnpackedAttributes",

src/transformers/index.js

@@ -34,6 +34,16 @@ let tmplImplicitContextTop = templateExpression(`
 	Object.assign({}, %%environment%%)
 `);
 
+let tmplConditionalExpression = templateExpression(`
+	(() => {
+		if (%%condition%%) {
+			return %%consequence%%;
+		} else {
+			return %%alternative%%;
+		}
+	})()
+`);
+
 let implicitContextCounter = 0;
 
 let trivial = {
@@ -56,9 +66,10 @@ let trivial = {
 		},
 		NixIdentifier: (node, { getContext }) => {
 			// FIXME: Mangle reserved keywords like `const`
-			let safeName = (node.name === "import")
-				? "$import"
-				: node.name;
+			// let safeName = (node.name === "import")
+			// 	? "$import"
+			// 	: node.name;
+			let safeName = node.name;
 
 			if (getContext("identifierType") === "define") {
 				return types.identifier(safeName);
@@ -69,6 +80,15 @@ let trivial = {
 				return tmplIdentifierReference({ name: safeName });
 			}
 		},
+		NixUnaryOperation: (_node, { defer }) => {
+			return defer((node) => {
+				if (node.operator === "-") {
+					return types.unaryExpression(node.operator, node.argument, true);
+				} else {
+					throw new Error(`Unsupported operator: ${node.operator}`);
+				}
+			});
+		},
 		NixBinaryOperation: (_node, { defer }) => {
 			return defer((node) => {
 				// FIXME: Verify that all the 'operator' values match between Nix and JS!
@@ -94,9 +114,9 @@ let trivial = {
 			setContext(null, "implicitContext", contextName);
 
 			return defer((node) => {
-			let setupCode = (hasParent)
-				? tmplImplicitContextNested({ environment: node.environment, parent: parentContext })
-				: tmplImplicitContextTop({ environment: node.environment });
+				let setupCode = (hasParent)
+					? tmplImplicitContextNested({ environment: node.environment, parent: parentContext })
+					: tmplImplicitContextTop({ environment: node.environment });
 
 				return tmplWithWrapper({
 					contextName: contextName,
@@ -104,6 +124,16 @@ let trivial = {
 					body: node.body
 				});
 			});
+		},
+		NixConditional: (_node, { defer }) => {
+			// condition, consequence, alternative
+			return defer((node) => {
+				return tmplConditionalExpression({
+					condition: node.condition,
+					consequence: node.consequence,
+					alternative: node.alternative
+				});
+			});
 		}
 	}
 };