Remove exponentiationOperator, asyncFunctions, trailingFunctionCommas

README.md

@@ -92,9 +92,6 @@ require("babylon").parse("code", {
   sourceType: "module",
 
   plugins: [
-    // enable experimental async functions
-    "asyncFunctions",
-
     // enable jsx and flow syntax
     "jsx",
     "flow"
@@ -106,15 +103,12 @@ require("babylon").parse("code", {
 
  - `jsx`
  - `flow`
- - `asyncFunctions`
  - `classConstructorCall`
  - `doExpressions`
- - `trailingFunctionCommas`
  - `objectRestSpread`
  - `decorators`
  - `classProperties`
  - `exportExtensions`
- - `exponentiationOperator`
  - `asyncGenerators`
  - `functionBind`
  - `functionSent`

src/parser/expression.js

@@ -299,7 +299,7 @@ pp.parseSubscripts = function (base, startPos, startLoc, noCalls) {
 
       let node = this.startNodeAt(startPos, startLoc);
       node.callee = base;
-      node.arguments = this.parseCallExpressionArguments(tt.parenR, this.hasPlugin("trailingFunctionCommas"), possibleAsync);
+      node.arguments = this.parseCallExpressionArguments(tt.parenR, possibleAsync);
       base = this.finishNode(node, "CallExpression");
 
       if (possibleAsync && this.shouldParseAsyncArrow()) {
@@ -318,7 +318,7 @@ pp.parseSubscripts = function (base, startPos, startLoc, noCalls) {
   }
 };
 
-pp.parseCallExpressionArguments = function (close, allowTrailingComma, possibleAsyncArrow) {
+pp.parseCallExpressionArguments = function (close, possibleAsyncArrow) {
   let innerParenStart;
 
   let elts = [], first = true;
@@ -327,7 +327,7 @@ pp.parseCallExpressionArguments = function (close, allowTrailingComma, possibleA
       first = false;
     } else {
       this.expect(tt.comma);
-      if (allowTrailingComma && this.eat(close)) break;
+      if (this.eat(close)) break;
     }
 
     // we need to make sure that if this is an async arrow functions, that we don't allow inner parens inside the params
@@ -351,7 +351,6 @@ pp.shouldParseAsyncArrow = function () {
 };
 
 pp.parseAsyncArrowFromCallExpression = function (node, call) {
-  if (!this.hasPlugin("asyncFunctions")) this.unexpected();
   this.expect(tt.arrow);
   return this.parseArrowExpression(node, call.arguments, true);
 };
@@ -396,24 +395,22 @@ pp.parseExprAtom = function (refShorthandDefaultPos) {
 
     case tt.name:
       node = this.startNode();
-      let allowAwait = this.hasPlugin("asyncFunctions") && this.state.value === "await" && this.state.inAsync;
+      let allowAwait = this.state.value === "await" && this.state.inAsync;
       let allowYield = this.shouldAllowYieldIdentifier();
       let id = this.parseIdentifier(allowAwait || allowYield);
 
-      if (this.hasPlugin("asyncFunctions")) {
-        if (id.name === "await") {
-          if (this.state.inAsync || this.inModule) {
-            return this.parseAwait(node);
-          }
-        } else if (id.name === "async" && this.match(tt._function) && !this.canInsertSemicolon()) {
-          this.next();
-          return this.parseFunction(node, false, false, true);
-        } else if (canBeArrow && id.name === "async" && this.match(tt.name)) {
-          let params = [this.parseIdentifier()];
-          this.expect(tt.arrow);
-          // let foo = bar => {};
-          return this.parseArrowExpression(node, params, true);
+      if (id.name === "await") {
+        if (this.state.inAsync || this.inModule) {
+          return this.parseAwait(node);
         }
+      } else if (id.name === "async" && this.match(tt._function) && !this.canInsertSemicolon()) {
+        this.next();
+        return this.parseFunction(node, false, false, true);
+      } else if (canBeArrow && id.name === "async" && this.match(tt.name)) {
+        let params = [this.parseIdentifier()];
+        this.expect(tt.arrow);
+        // let foo = bar => {};
+        return this.parseArrowExpression(node, params, true);
       }
 
       if (canBeArrow && !this.canInsertSemicolon() && this.eat(tt.arrow)) {
@@ -466,7 +463,7 @@ pp.parseExprAtom = function (refShorthandDefaultPos) {
     case tt.bracketL:
       node = this.startNode();
       this.next();
-      node.elements = this.parseExprList(tt.bracketR, true, true, refShorthandDefaultPos);
+      node.elements = this.parseExprList(tt.bracketR, true, refShorthandDefaultPos);
       this.toReferencedList(node.elements);
       return this.finishNode(node, "ArrayExpression");
 
@@ -559,7 +556,7 @@ pp.parseParenAndDistinguishExpression = function (startPos, startLoc, canBeArrow
       first = false;
     } else {
       this.expect(tt.comma, refNeedsArrowPos.start || null);
-      if (this.match(tt.parenR) && this.hasPlugin("trailingFunctionCommas")) {
+      if (this.match(tt.parenR)) {
         optionalCommaStart = this.state.start;
         break;
       }
@@ -641,7 +638,7 @@ pp.parseNew = function () {
   node.callee = this.parseNoCallExpr();
 
   if (this.eat(tt.parenL)) {
-    node.arguments = this.parseExprList(tt.parenR, this.hasPlugin("trailingFunctionCommas"));
+    node.arguments = this.parseExprList(tt.parenR);
     this.toReferencedList(node.arguments);
   } else {
     node.arguments = [];
@@ -727,7 +724,7 @@ pp.parseObj = function (isPattern, refShorthandDefaultPos) {
       isGenerator = this.eat(tt.star);
     }
 
-    if (!isPattern && this.hasPlugin("asyncFunctions") && this.isContextual("async")) {
+    if (!isPattern && this.isContextual("async")) {
       if (isGenerator) this.unexpected();
 
       let asyncId = this.parseIdentifier();
@@ -833,9 +830,7 @@ pp.initFunction = function (node, isAsync) {
   node.id = null;
   node.generator = false;
   node.expression = false;
-  if (this.hasPlugin("asyncFunctions")) {
-    node.async = !!isAsync;
-  }
+  node.async = !!isAsync;
 };
 
 // Parse object or class method.
@@ -845,7 +840,7 @@ pp.parseMethod = function (node, isGenerator, isAsync) {
   this.state.inMethod = node.kind || true;
   this.initFunction(node, isAsync);
   this.expect(tt.parenL);
-  node.params = this.parseBindingList(tt.parenR, false, this.hasPlugin("trailingFunctionCommas"));
+  node.params = this.parseBindingList(tt.parenR);
   node.generator = isGenerator;
   this.parseFunctionBody(node);
   this.state.inMethod = oldInMethod;
@@ -929,14 +924,14 @@ pp.parseFunctionBody = function (node, allowExpression) {
 // nothing in between them to be parsed as `null` (which is needed
 // for array literals).
 
-pp.parseExprList = function (close, allowTrailingComma, allowEmpty, refShorthandDefaultPos) {
+pp.parseExprList = function (close, allowEmpty, refShorthandDefaultPos) {
   let elts = [], first = true;
   while (!this.eat(close)) {
     if (first) {
       first = false;
     } else {
       this.expect(tt.comma);
-      if (allowTrailingComma && this.eat(close)) break;
+      if (this.eat(close)) break;
     }
 
     elts.push(this.parseExprListItem(allowEmpty, refShorthandDefaultPos));

src/parser/lval.js

@@ -126,14 +126,14 @@ pp.parseBindingAtom = function () {
   switch (this.state.type) {
     case tt._yield:
       if (this.state.strict || this.state.inGenerator) this.unexpected();
-
+      // fall-through
     case tt.name:
       return this.parseIdentifier(true);
 
     case tt.bracketL:
       let node = this.startNode();
       this.next();
-      node.elements = this.parseBindingList(tt.bracketR, true, true);
+      node.elements = this.parseBindingList(tt.bracketR, true);
       return this.finishNode(node, "ArrayPattern");
 
     case tt.braceL:
@@ -144,7 +144,7 @@ pp.parseBindingAtom = function () {
   }
 };
 
-pp.parseBindingList = function (close, allowEmpty, allowTrailingComma) {
+pp.parseBindingList = function (close, allowEmpty) {
   let elts = [];
   let first = true;
   while (!this.eat(close)) {
@@ -155,7 +155,7 @@ pp.parseBindingList = function (close, allowEmpty, allowTrailingComma) {
     }
     if (allowEmpty && this.match(tt.comma)) {
       elts.push(null);
-    } else if (allowTrailingComma && this.eat(close)) {
+    } else if (this.eat(close)) {
       break;
     } else if (this.match(tt.ellipsis)) {
       elts.push(this.parseAssignableListItemTypes(this.parseRest()));

src/parser/statement.js

@@ -110,7 +110,7 @@ pp.parseStatement = function (declaration, topLevel) {
       return starttype === tt._import ? this.parseImport(node) : this.parseExport(node);
 
     case tt.name:
-      if (this.hasPlugin("asyncFunctions") && this.state.value === "async") {
+      if (this.state.value === "async") {
         // peek ahead and see if next token is a function
         let state = this.state.clone();
         this.next();
@@ -603,7 +603,7 @@ pp.parseFunction = function (node, isStatement, allowExpressionBody, isAsync, op
 
 pp.parseFunctionParams = function (node) {
   this.expect(tt.parenL);
-  node.params = this.parseBindingList(tt.parenR, false, this.hasPlugin("trailingFunctionCommas"));
+  node.params = this.parseBindingList(tt.parenR);
 };
 
 // Parse a class declaration or literal (depending on the
@@ -684,7 +684,7 @@ pp.parseClassBody = function (node) {
       }
     }
 
-    let isAsyncMethod = this.hasPlugin("asyncFunctions") && !this.match(tt.parenL) && !method.computed && method.key.type === "Identifier" && method.key.name === "async";
+    let isAsyncMethod = !this.match(tt.parenL) && !method.computed && method.key.type === "Identifier" && method.key.name === "async";
     if (isAsyncMethod) {
       if (this.hasPlugin("asyncGenerators") && this.eat(tt.star)) isGenerator = true;
       isAsync = true;
@@ -900,7 +900,7 @@ pp.parseExportFrom = function (node, expect?) {
 };
 
 pp.shouldParseExportDeclaration = function () {
-  return this.hasPlugin("asyncFunctions") && this.isContextual("async");
+  return this.isContextual("async");
 };
 
 pp.checkExport = function (node) {

src/tokenizer/index.js

@@ -304,7 +304,7 @@ export default class Tokenizer {
     let width = 1;
     let next = this.input.charCodeAt(this.state.pos + 1);
 
-    if (next === 42 && this.hasPlugin("exponentiationOperator")) { // '*'
+    if (next === 42) { // '*'
       width++;
       next = this.input.charCodeAt(this.state.pos + 2);
       type = tt.exponent;