Initial operator. Need to fix the grammar for unaryExpression

src/compiler/checker.ts

@@ -9842,7 +9842,9 @@ namespace ts {
             let rightType = checkExpression(node.right, contextualMapper);
             switch (operator) {
                 case SyntaxKind.AsteriskToken:
+                case SyntaxKind.AsteriskAsteriskToken:
                 case SyntaxKind.AsteriskEqualsToken:
+                case SyntaxKind.AsteriskAsteriskEqualsToken:
                 case SyntaxKind.SlashToken:
                 case SyntaxKind.SlashEqualsToken:
                 case SyntaxKind.PercentToken:
@@ -9861,7 +9863,7 @@ namespace ts {
                 case SyntaxKind.CaretEqualsToken:
                 case SyntaxKind.AmpersandToken:
                 case SyntaxKind.AmpersandEqualsToken:
-                    // TypeScript 1.0 spec (April 2014): 4.15.1
+                    // TypeScript 1.0 spec (April 2014): 4.19.1
                     // These operators require their operands to be of type Any, the Number primitive type,
                     // or an enum type. Operands of an enum type are treated
                     // as having the primitive type Number. If one operand is the null or undefined value,
@@ -9890,7 +9892,7 @@ namespace ts {
                     return numberType;
                 case SyntaxKind.PlusToken:
                 case SyntaxKind.PlusEqualsToken:
-                    // TypeScript 1.0 spec (April 2014): 4.15.2
+                    // TypeScript 1.0 spec (April 2014): 4.19.2
                     // The binary + operator requires both operands to be of the Number primitive type or an enum type,
                     // or at least one of the operands to be of type Any or the String primitive type.
 

src/compiler/emitter.ts

@@ -2522,12 +2522,23 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         emitNodeWithoutSourceMap(node.left);
                         write(`", `);
                     }
-                    emit(node.left);
-                    let indentedBeforeOperator = indentIfOnDifferentLines(node, node.left, node.operatorToken, node.operatorToken.kind !== SyntaxKind.CommaToken ? " " : undefined);
-                    write(tokenToString(node.operatorToken.kind));
-                    let indentedAfterOperator = indentIfOnDifferentLines(node, node.operatorToken, node.right, " ");
-                    emit(node.right);
-                    decreaseIndentIf(indentedBeforeOperator, indentedAfterOperator);
+
+                    if (languageVersion < ScriptTarget.ES7 && node.operatorToken.kind === SyntaxKind.AsteriskAsteriskToken) {
+                        write("Math.pow(");
+                        emit(node.left);
+                        write(", ");
+                        emit(node.right);
+                        write(")");
+                    }
+                    else {
+                        emit(node.left);
+                        let indentedBeforeOperator = indentIfOnDifferentLines(node, node.left, node.operatorToken, node.operatorToken.kind !== SyntaxKind.CommaToken ? " " : undefined);
+                        write(tokenToString(node.operatorToken.kind));
+                        let indentedAfterOperator = indentIfOnDifferentLines(node, node.operatorToken, node.right, " ");
+                        emit(node.right);
+                        decreaseIndentIf(indentedBeforeOperator, indentedAfterOperator);
+                    }
+
                     if (exportChanged) {
                         write(")");
                     }

src/compiler/parser.ts

@@ -3015,7 +3015,11 @@ namespace ts {
                 let newPrecedence = getBinaryOperatorPrecedence();
 
                 // Check the precedence to see if we should "take" this operator
-                if (newPrecedence <= precedence) {
+                if (token === SyntaxKind.AsteriskAsteriskToken && newPrecedence < precedence) {
+                    // ** operator is right-assocative
+                    break;
+                }
+                else if (token !== SyntaxKind.AsteriskAsteriskToken && newPrecedence <= precedence) {
                     break;
                 }
 
@@ -3089,6 +3093,8 @@ namespace ts {
                 case SyntaxKind.SlashToken:
                 case SyntaxKind.PercentToken:
                     return 10;
+                case SyntaxKind.AsteriskAsteriskToken:
+                    return 11;
             }
 
             // -1 is lower than all other precedences.  Returning it will cause binary expression

src/compiler/scanner.ts

@@ -136,6 +136,7 @@ namespace ts {
         "=>": SyntaxKind.EqualsGreaterThanToken,
         "+": SyntaxKind.PlusToken,
         "-": SyntaxKind.MinusToken,
+        "**": SyntaxKind.AsteriskAsteriskToken,
         "*": SyntaxKind.AsteriskToken,
         "/": SyntaxKind.SlashToken,
         "%": SyntaxKind.PercentToken,
@@ -158,6 +159,7 @@ namespace ts {
         "+=": SyntaxKind.PlusEqualsToken,
         "-=": SyntaxKind.MinusEqualsToken,
         "*=": SyntaxKind.AsteriskEqualsToken,
+        "**=": SyntaxKind.AsteriskAsteriskEqualsToken,
         "/=": SyntaxKind.SlashEqualsToken,
         "%=": SyntaxKind.PercentEqualsToken,
         "<<=": SyntaxKind.LessThanLessThanEqualsToken,
@@ -1212,6 +1214,12 @@ namespace ts {
                         if (text.charCodeAt(pos + 1) === CharacterCodes.equals) {
                             return pos += 2, token = SyntaxKind.AsteriskEqualsToken;
                         }
+                        if (text.charCodeAt(pos + 1) === CharacterCodes.asterisk) {
+                            if (text.charCodeAt(pos + 2) === CharacterCodes.equals) {
+                                return pos += 3, token = SyntaxKind.AsteriskAsteriskEqualsToken;
+                            }
+                            return pos += 2, token = SyntaxKind.AsteriskAsteriskToken;
+                        }
                         return pos++, token = SyntaxKind.AsteriskToken;
                     case CharacterCodes.plus:
                         if (text.charCodeAt(pos + 1) === CharacterCodes.plus) {

src/compiler/types.ts

@@ -64,6 +64,7 @@ namespace ts {
         PlusToken,
         MinusToken,
         AsteriskToken,
+        AsteriskAsteriskToken,
         SlashToken,
         PercentToken,
         PlusPlusToken,
@@ -86,6 +87,7 @@ namespace ts {
         PlusEqualsToken,
         MinusEqualsToken,
         AsteriskEqualsToken,
+        AsteriskAsteriskEqualsToken,
         SlashEqualsToken,
         PercentEqualsToken,
         LessThanLessThanEqualsToken,
@@ -702,13 +704,15 @@ namespace ts {
         contextualType?: Type;  // Used to temporarily assign a contextual type during overload resolution
     }
 
+    export type UnaryOrBinaryExpression = UnaryExpression | BinaryExpression;
+
     export interface UnaryExpression extends Expression {
         _unaryExpressionBrand: any;
     }
 
     export interface PrefixUnaryExpression extends UnaryExpression {
         operator: SyntaxKind;
-        operand: UnaryExpression;
+        operand: UnaryOrBinaryExpression;
     }
 
     export interface PostfixUnaryExpression extends PostfixExpression {
@@ -733,19 +737,19 @@ namespace ts {
     }
 
     export interface DeleteExpression extends UnaryExpression {
-        expression: UnaryExpression;
+        expression: UnaryOrBinaryExpression;
     }
 
     export interface TypeOfExpression extends UnaryExpression {
-        expression: UnaryExpression;
+        expression: UnaryOrBinaryExpression;
     }
 
     export interface VoidExpression extends UnaryExpression {
-        expression: UnaryExpression;
+        expression: UnaryOrBinaryExpression;
     }
 
     export interface AwaitExpression extends UnaryExpression {
-        expression: UnaryExpression;
+        expression: UnaryOrBinaryExpression;
     }
 
     export interface YieldExpression extends Expression {
@@ -852,7 +856,7 @@ namespace ts {
 
     export interface TypeAssertion extends UnaryExpression {
         type: TypeNode;
-        expression: UnaryExpression;
+        expression: UnaryOrBinaryExpression;
     }
 
     export type AssertionExpression = TypeAssertion | AsExpression;
@@ -2101,6 +2105,7 @@ namespace ts {
         ES3 = 0,
         ES5 = 1,
         ES6 = 2,
+        ES7 = 3,
         Latest = ES6,
     }