small refactor: use JS.* prefix for our other JS extensions

it's not clear what will end up in js_ast vs ddc, so nice to use js_ast conventions for the JS nodes

[email protected]

Review URL: https://codereview.chromium.org/1111893002

Author: John Messerly

pkg/dev_compiler/lib/src/codegen/js_codegen.dart

@@ -31,8 +31,8 @@ import 'package:dev_compiler/src/utils.dart';
 
 import 'code_generator.dart';
 import 'js_field_storage.dart';
-import 'js_names.dart' show JSTemporary, invalidJSStaticMethodName;
-import 'js_metalet.dart';
+import 'js_names.dart' as JS;
+import 'js_metalet.dart' as JS;
 import 'js_printer.dart' show writeJsLibrary;
 import 'side_effect_analysis.dart';
 
@@ -71,17 +71,17 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
   final _exports = new Set<String>();
   final _lazyFields = <VariableDeclaration>[];
   final _properties = <FunctionDeclaration>[];
-  final _privateNames = new HashMap<String, JSTemporary>();
+  final _privateNames = new HashMap<String, JS.TemporaryId>();
   final _extensionMethodNames = new HashSet<String>();
   final _pendingStatements = <JS.Statement>[];
-  final _temps = new HashMap<Element, JSTemporary>();
+  final _temps = new HashMap<Element, JS.TemporaryId>();
 
   /// The name for the library's exports inside itself.
   /// This much be a constant because we interpolate it into template strings,
   /// and otherwise it would break caching for them.
   /// `exports` was chosen as the most similar to ES module patterns.
-  final JSTemporary _exportsVar = new JSTemporary('exports');
-  final JSTemporary _namedArgTemp = new JSTemporary('opts');
+  final _exportsVar = new JS.TemporaryId('exports');
+  final _namedArgTemp = new JS.TemporaryId('opts');
 
   /// Classes we have not emitted yet. Values can be [ClassDeclaration] or
   /// [ClassTypeAlias].
@@ -1097,8 +1097,8 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
     return new JS.Identifier(name);
   }
 
-  JSTemporary _getTemp(Object key, String name) =>
-      _temps.putIfAbsent(key, () => new JSTemporary(name));
+  JS.TemporaryId _getTemp(Object key, String name) =>
+      _temps.putIfAbsent(key, () => new JS.TemporaryId(name));
 
   JS.ArrayInitializer _emitTypeNames(List<DartType> types) {
     return new JS.ArrayInitializer(types.map(_emitTypeName).toList());
@@ -1197,7 +1197,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
         context: node);
   }
 
-  JSMetaLet _emitOpAssign(
+  JS.MetaLet _emitOpAssign(
       Expression left, Expression right, String op, ExecutableElement element,
       {Expression context}) {
     // Desugar `x += y` as `x = x + y`, ensuring that if `x` has subexpressions
@@ -1207,7 +1207,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
     var inc = AstBuilder.binaryExpression(lhs, op, right);
     inc.staticElement = element;
     inc.staticType = getStaticType(left);
-    return new JSMetaLet(vars, [_emitSet(lhs, inc)]);
+    return new JS.MetaLet(vars, [_emitSet(lhs, inc)]);
   }
 
   JS.Expression _emitSet(Expression lhs, Expression rhs) {
@@ -1778,7 +1778,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
   ///     // psuedocode mix of Scheme and JS:
   ///     (let* (x1=expr1, x2=expr2, t=expr1[expr2]) { x1[x2] = t + 1; t })
   ///
-  /// The [JSMetaLet] nodes automatically simplify themselves if they can.
+  /// The [JS.JS.MetaLet] nodes automatically simplify themselves if they can.
   /// For example, if the result value is not used, then `t` goes away.
   @override
   JS.Expression visitPostfixExpression(PostfixExpression node) {
@@ -1809,7 +1809,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
       ..staticType = getStaticType(expr);
 
     var body = [_emitSet(left, increment), _visit(x)];
-    return new JSMetaLet(vars, body, statelessResult: true);
+    return new JS.MetaLet(vars, body, statelessResult: true);
   }
 
   @override
@@ -1827,7 +1827,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
         var vars = {};
         var x = _bindLeftHandSide(vars, expr, context: expr);
         var body = js.call('# = # $mathop 1', [_visit(x), notNull(x)]);
-        return new JSMetaLet(vars, [body]);
+        return new JS.MetaLet(vars, [body]);
       } else {
         return js.call('$op#', notNull(expr));
       }
@@ -1856,7 +1856,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
     _cascadeTarget = _bindValue(vars, '_', node.target, context: node);
     var sections = _visitList(node.cascadeSections);
     sections.add(_visit(_cascadeTarget));
-    var result = new JSMetaLet(vars, sections, statelessResult: true);
+    var result = new JS.MetaLet(vars, sections, statelessResult: true);
     _cascadeTarget = savedCascadeTemp;
     return result;
   }
@@ -2360,7 +2360,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
       {DartType type, bool unary: false, bool isStatic: false}) {
     if (name.startsWith('_')) {
       return _privateNames.putIfAbsent(
-          name, () => _initSymbol(new JSTemporary(name)));
+          name, () => _initSymbol(new JS.TemporaryId(name)));
     }
 
     // Check for extension method:
@@ -2374,7 +2374,7 @@ class JSCodegenVisitor extends GeneralizingAstVisitor with ConversionVisitor {
       name = 'unary-';
     }
 
-    if (isStatic && invalidJSStaticMethodName(name)) {
+    if (isStatic && JS.invalidStaticMethodName(name)) {
       // Choose an string name. Use an invalid identifier so it won't conflict
       // with any valid member names.
       // TODO(jmesserly): this works around the problem, but I'm pretty sure we

pkg/dev_compiler/lib/src/codegen/js_metalet.dart

@@ -8,7 +8,7 @@ library dev_compiler.src.codegen.js_metalet;
 import 'package:dev_compiler/src/js/js_ast.dart';
 import 'package:dev_compiler/src/js/precedence.dart';
 
-import 'js_names.dart' show JSTemporary;
+import 'js_names.dart' show TemporaryId;
 
 /// A synthetic `let*` node, similar to that found in Scheme.
 ///
@@ -17,7 +17,7 @@ import 'js_names.dart' show JSTemporary;
 ///     // psuedocode mix of Scheme and JS:
 ///     (let* (x1=expr1, x2=expr2, t=x1[x2]) { x1[x2] = t + 1; t })
 ///
-/// [JSMetaLet] will simplify itself automatically when [toExpression],
+/// [MetaLet] will simplify itself automatically when [toExpression],
 /// [toStatement], or [toReturn] is called.
 ///
 /// * variables used once will be inlined.
@@ -29,7 +29,7 @@ import 'js_names.dart' show JSTemporary;
 /// around statelessness (such as `final` variables). [variables] should not
 /// be created for these Dart expressions.
 ///
-class JSMetaLet extends Expression {
+class MetaLet extends Expression {
   /// Creates a temporary to contain the value of [expr]. The temporary can be
   /// used multiple times in the resulting expression. For example:
   /// `expr ** 2` could be compiled as `expr * expr`. The temporary scope will
@@ -52,7 +52,7 @@ class JSMetaLet extends Expression {
   /// This happens multiple times, so ensure the expression form is cached.
   Expression _expression;
 
-  JSMetaLet(this.variables, this.body, {this.statelessResult: false});
+  MetaLet(this.variables, this.body, {this.statelessResult: false});
 
   /// Returns an expression that ignores the result. This is a cross between
   /// [toExpression] and [toStatement]. Used for C-style for-loop updaters,
@@ -74,7 +74,7 @@ class JSMetaLet extends Expression {
 
       var exprs = body.toList();
       exprs.add(exprs.removeLast().toAssignExpression(left));
-      return new JSMetaLet(variables, exprs);
+      return new MetaLet(variables, exprs);
     }
     return super.toAssignExpression(left);
   }
@@ -136,7 +136,7 @@ class JSMetaLet extends Expression {
         [new VariableDeclarationList('let', vars).toStatement(), block]);
   }
 
-  Node _build(List<JSTemporary> params, List<Expression> values, Node node) {
+  Node _build(List<TemporaryId> params, List<Expression> values, Node node) {
     // Visit the tree and count how many times each temp was used.
     var counter = new _VariableUseCounter();
     node.accept(counter);
@@ -154,7 +154,7 @@ class JSMetaLet extends Expression {
       if (n == null || n < 2) {
         substitutions[name] = _substitute(init);
       } else {
-        params.add(substitutions[name] = new JSTemporary(name));
+        params.add(substitutions[name] = new TemporaryId(name));
         values.add(init);
       }
     });
@@ -178,7 +178,7 @@ class JSMetaLet extends Expression {
   ///
   ///     ((_) => _.addAll(result), _.add(2), result = _)([])
   ///
-  JSMetaLet _simplifyAssignment(Identifier left, {bool isDeclaration: false}) {
+  MetaLet _simplifyAssignment(Identifier left, {bool isDeclaration: false}) {
     // See if the result value is a let* temporary variable.
     if (body.last is! InterpolatedExpression) return null;
 
@@ -204,7 +204,7 @@ class JSMetaLet extends Expression {
     if (isDeclaration) {
       // Technically, putting one of these in a comma expression is not
       // legal. However when isDeclaration is true, toStatement will be
-      // called immediately on the JSMetaLet, which results in legal JS.
+      // called immediately on the MetaLet, which results in legal JS.
       assign = new VariableDeclarationList(
           'let', [new VariableInitialization(left, value)]);
     } else {
@@ -213,7 +213,7 @@ class JSMetaLet extends Expression {
 
     var newBody = new Expression.binary([assign]..addAll(body), ',');
     Binary comma = new Template(null, newBody).safeCreate({name: left});
-    return new JSMetaLet(vars, comma.commaToExpressionList(),
+    return new MetaLet(vars, comma.commaToExpressionList(),
         statelessResult: statelessResult);
   }
 }

pkg/dev_compiler/lib/src/codegen/js_names.dart

@@ -13,8 +13,8 @@ import 'package:dev_compiler/src/js/js_ast.dart';
 /// generation without needing global knowledge. See [JSNamer].
 ///
 // TODO(jmesserly): move into js_ast? add a boolean to Identifier?
-class JSTemporary extends Identifier {
-  JSTemporary(String name) : super(name);
+class TemporaryId extends Identifier {
+  TemporaryId(String name) : super(name);
 }
 
 /// This class has two purposes:
@@ -28,10 +28,10 @@ class JSTemporary extends Identifier {
 /// [Identifiers] are never renamed unless they are an invalid identifier, like
 /// `function` or `instanceof`, and their `name` field controls whether they
 /// refer to the same variable.
-class JSNamer extends LocalNamer {
+class TemporaryNamer extends LocalNamer {
   final Map<Object, String> renames;
 
-  JSNamer(Node node) : renames = new _RenameVisitor.build(node).renames;
+  TemporaryNamer(Node node) : renames = new _RenameVisitor.build(node).renames;
 
   String getName(Identifier node) {
     var rename = renames[identifierKey(node)];
@@ -152,9 +152,9 @@ class _RenameVisitor extends VariableDeclarationVisitor {
   static String _findName(Object id, Set<String> usedNames) {
     String name;
     bool valid;
-    if (id is JSTemporary) {
+    if (id is TemporaryId) {
       name = id.name;
-      valid = !invalidJSVariableName(name);
+      valid = !invalidVariableName(name);
     } else {
       name = id;
       valid = false;
@@ -179,14 +179,14 @@ class _RenameVisitor extends VariableDeclarationVisitor {
 }
 
 bool needsRename(Identifier node) =>
-    node is JSTemporary || node.allowRename && invalidJSVariableName(node.name);
+    node is TemporaryId || node.allowRename && invalidVariableName(node.name);
 
 Object /*String|JSTemporary*/ identifierKey(Identifier node) =>
-    node is JSTemporary ? node : node.name;
+    node is TemporaryId ? node : node.name;
 
 /// Returns true for invalid JS variable names, such as keywords.
 /// Also handles invalid variable names in strict mode, like "arguments".
-bool invalidJSVariableName(String keyword, {bool strictMode: true}) {
+bool invalidVariableName(String keyword, {bool strictMode: true}) {
   switch (keyword) {
     case "break":
     case "case":
@@ -233,7 +233,7 @@ bool invalidJSVariableName(String keyword, {bool strictMode: true}) {
 
 /// Returns true for invalid static method names in strict mode.
 /// In particular, "caller" "callee" and "arguments" cannot be used.
-bool invalidJSStaticMethodName(String name) {
+bool invalidStaticMethodName(String name) {
   switch (name) {
     case "arguments":
     case "caller":

pkg/dev_compiler/lib/src/codegen/js_printer.dart

@@ -15,7 +15,7 @@ import 'package:dev_compiler/src/js/js_ast.dart' as JS;
 import 'package:dev_compiler/src/utils.dart'
     show computeHash, locationForOffset;
 
-import 'js_names.dart' show JSNamer;
+import 'js_names.dart' show TemporaryNamer;
 
 String writeJsLibrary(JS.Program jsTree, String outputPath,
     {bool emitSourceMaps: false}) {
@@ -40,7 +40,8 @@ String writeJsLibrary(JS.Program jsTree, String outputPath,
 
 void writeNodeToContext(JS.Node node, JS.JavaScriptPrintingContext context) {
   var opts = new JS.JavaScriptPrintingOptions(allowKeywordsInProperties: true);
-  node.accept(new JS.Printer(opts, context, localNamer: new JSNamer(node)));
+  node.accept(
+      new JS.Printer(opts, context, localNamer: new TemporaryNamer(node)));
 }
 
 String jsNodeToString(JS.Node node) {

pkg/dev_compiler/lib/src/utils.dart

@@ -31,7 +31,7 @@ import 'package:crypto/crypto.dart' show CryptoUtils, MD5;
 import 'package:source_span/source_span.dart';
 import 'package:yaml/yaml.dart';
 
-import 'codegen/js_names.dart' show invalidJSVariableName;
+import 'codegen/js_names.dart' show invalidVariableName;
 
 bool isDartPrivateLibrary(LibraryElement library) {
   var uri = library.source.uri;
@@ -69,7 +69,7 @@ String _toIdentifier(String name) {
   var result = buffer != null ? '$buffer' : name;
   // Ensure the identifier first character is not numeric and that the whole
   // identifier is not a keyword.
-  if (result.startsWith(new RegExp('[0-9]')) || invalidJSVariableName(result)) {
+  if (result.startsWith(new RegExp('[0-9]')) || invalidVariableName(result)) {
     return '\$$result';
   }
   return result;