expect(value)
+ * @since 2.0
+ */
+ function expectCommaSeparator() {
+ var token;
+
+ if (extra.errors) {
+ token = lookahead;
+ if (token.type === Token.Punctuator && token.value === ',') {
+ lex();
+ } else if (token.type === Token.Punctuator && token.value === ';') {
+ lex();
+ tolerateUnexpectedToken(token);
+ } else {
+ tolerateUnexpectedToken(token, Messages.UnexpectedToken);
+ }
+ } else {
+ expect(',');
+ }
+ }
+
+ // Expect the next token to match the specified keyword.
+ // If not, an exception will be thrown.
+
+ function expectKeyword(keyword) {
+ var token = lex();
+ if (token.type !== Token.Keyword || token.value !== keyword) {
+ throwUnexpectedToken(token);
+ }
+ }
+
+ // Return true if the next token matches the specified punctuator.
+
+ function match(value) {
+ return lookahead.type === Token.Punctuator && lookahead.value === value;
+ }
+
+ // Return true if the next token matches the specified keyword
+
+ function matchKeyword(keyword) {
+ return lookahead.type === Token.Keyword && lookahead.value === keyword;
+ }
+
+ // Return true if the next token matches the specified contextual keyword
+ // (where an identifier is sometimes a keyword depending on the context)
+
+ function matchContextualKeyword(keyword) {
+ return lookahead.type === Token.Identifier && lookahead.value === keyword;
+ }
+
+ // Return true if the next token is an assignment operator
+
+ function matchAssign() {
+ var op;
+
+ if (lookahead.type !== Token.Punctuator) {
+ return false;
+ }
+ op = lookahead.value;
+ return op === '=' ||
+ op === '*=' ||
+ op === '/=' ||
+ op === '%=' ||
+ op === '+=' ||
+ op === '-=' ||
+ op === '<<=' ||
+ op === '>>=' ||
+ op === '>>>=' ||
+ op === '&=' ||
+ op === '^=' ||
+ op === '|=';
+ }
+
+ function consumeSemicolon() {
+ // Catch the very common case first: immediately a semicolon (U+003B).
+ if (source.charCodeAt(startIndex) === 0x3B || match(';')) {
+ lex();
+ return;
+ }
+
+ if (hasLineTerminator) {
+ return;
+ }
+
+ // FIXME(ikarienator): this is seemingly an issue in the previous location info convention.
+ lastIndex = startIndex;
+ lastLineNumber = startLineNumber;
+ lastLineStart = startLineStart;
+
+ if (lookahead.type !== Token.EOF && !match('}')) {
+ throwUnexpectedToken(lookahead);
+ }
+ }
+
+ // Cover grammar support.
+ //
+ // When an assignment expression position starts with an left parenthesis, the determination of the type
+ // of the syntax is to be deferred arbitrarily long until the end of the parentheses pair (plus a lookahead)
+ // or the first comma. This situation also defers the determination of all the expressions nested in the pair.
+ //
+ // There are three productions that can be parsed in a parentheses pair that needs to be determined
+ // after the outermost pair is closed. They are:
+ //
+ // 1. AssignmentExpression
+ // 2. BindingElements
+ // 3. AssignmentTargets
+ //
+ // In order to avoid exponential backtracking, we use two flags to denote if the production can be
+ // binding element or assignment target.
+ //
+ // The three productions have the relationship:
+ //
+ // BindingElements ⊆ AssignmentTargets ⊆ AssignmentExpression
+ //
+ // with a single exception that CoverInitializedName when used directly in an Expression, generates
+ // an early error. Therefore, we need the third state, firstCoverInitializedNameError, to track the
+ // first usage of CoverInitializedName and report it when we reached the end of the parentheses pair.
+ //
+ // isolateCoverGrammar function runs the given parser function with a new cover grammar context, and it does not
+ // effect the current flags. This means the production the parser parses is only used as an expression. Therefore
+ // the CoverInitializedName check is conducted.
+ //
+ // inheritCoverGrammar function runs the given parse function with a new cover grammar context, and it propagates
+ // the flags outside of the parser. This means the production the parser parses is used as a part of a potential
+ // pattern. The CoverInitializedName check is deferred.
+ function isolateCoverGrammar(parser) {
+ var oldIsBindingElement = isBindingElement,
+ oldIsAssignmentTarget = isAssignmentTarget,
+ oldFirstCoverInitializedNameError = firstCoverInitializedNameError,
+ result;
+ isBindingElement = true;
+ isAssignmentTarget = true;
+ firstCoverInitializedNameError = null;
+ result = parser();
+ if (firstCoverInitializedNameError !== null) {
+ throwUnexpectedToken(firstCoverInitializedNameError);
+ }
+ isBindingElement = oldIsBindingElement;
+ isAssignmentTarget = oldIsAssignmentTarget;
+ firstCoverInitializedNameError = oldFirstCoverInitializedNameError;
+ return result;
+ }
+
+ function inheritCoverGrammar(parser) {
+ var oldIsBindingElement = isBindingElement,
+ oldIsAssignmentTarget = isAssignmentTarget,
+ oldFirstCoverInitializedNameError = firstCoverInitializedNameError,
+ result;
+ isBindingElement = true;
+ isAssignmentTarget = true;
+ firstCoverInitializedNameError = null;
+ result = parser();
+ isBindingElement = isBindingElement && oldIsBindingElement;
+ isAssignmentTarget = isAssignmentTarget && oldIsAssignmentTarget;
+ firstCoverInitializedNameError = oldFirstCoverInitializedNameError || firstCoverInitializedNameError;
+ return result;
+ }
+
+ // ECMA-262 13.3.3 Destructuring Binding Patterns
+
+ function parseArrayPattern(params, kind) {
+ var node = new Node(), elements = [], rest, restNode;
+ expect('[');
+
+ while (!match(']')) {
+ if (match(',')) {
+ lex();
+ elements.push(null);
+ } else {
+ if (match('...')) {
+ restNode = new Node();
+ lex();
+ params.push(lookahead);
+ rest = parseVariableIdentifier(kind);
+ elements.push(restNode.finishRestElement(rest));
+ break;
+ } else {
+ elements.push(parsePatternWithDefault(params, kind));
+ }
+ if (!match(']')) {
+ expect(',');
+ }
+ }
+
+ }
+
+ expect(']');
+
+ return node.finishArrayPattern(elements);
+ }
+
+ function parsePropertyPattern(params, kind) {
+ var node = new Node(), key, keyToken, computed = match('['), init;
+ if (lookahead.type === Token.Identifier) {
+ keyToken = lookahead;
+ key = parseVariableIdentifier();
+ if (match('=')) {
+ params.push(keyToken);
+ lex();
+ init = parseAssignmentExpression();
+
+ return node.finishProperty(
+ 'init', key, false,
+ new WrappingNode(keyToken).finishAssignmentPattern(key, init), false, false);
+ } else if (!match(':')) {
+ params.push(keyToken);
+ return node.finishProperty('init', key, false, key, false, true);
+ }
+ } else {
+ key = parseObjectPropertyKey();
+ }
+ expect(':');
+ init = parsePatternWithDefault(params, kind);
+ return node.finishProperty('init', key, computed, init, false, false);
+ }
+
+ function parseObjectPattern(params, kind) {
+ var node = new Node(), properties = [];
+
+ expect('{');
+
+ while (!match('}')) {
+ properties.push(parsePropertyPattern(params, kind));
+ if (!match('}')) {
+ expect(',');
+ }
+ }
+
+ lex();
+
+ return node.finishObjectPattern(properties);
+ }
+
+ function parsePattern(params, kind) {
+ if (match('[')) {
+ return parseArrayPattern(params, kind);
+ } else if (match('{')) {
+ return parseObjectPattern(params, kind);
+ } else if (matchKeyword('let')) {
+ if (kind === 'const' || kind === 'let') {
+ tolerateUnexpectedToken(lookahead, Messages.UnexpectedToken);
+ }
+ }
+
+ params.push(lookahead);
+ return parseVariableIdentifier(kind);
+ }
+
+ function parsePatternWithDefault(params, kind) {
+ var startToken = lookahead, pattern, previousAllowYield, right;
+ pattern = parsePattern(params, kind);
+ if (match('=')) {
+ lex();
+ previousAllowYield = state.allowYield;
+ state.allowYield = true;
+ right = isolateCoverGrammar(parseAssignmentExpression);
+ state.allowYield = previousAllowYield;
+ pattern = new WrappingNode(startToken).finishAssignmentPattern(pattern, right);
+ }
+ return pattern;
+ }
+
+ // ECMA-262 12.2.5 Array Initializer
+
+ function parseArrayInitializer() {
+ var elements = [], node = new Node(), restSpread;
+
+ expect('[');
+
+ while (!match(']')) {
+ if (match(',')) {
+ lex();
+ elements.push(null);
+ } else if (match('...')) {
+ restSpread = new Node();
+ lex();
+ restSpread.finishSpreadElement(inheritCoverGrammar(parseAssignmentExpression));
+
+ if (!match(']')) {
+ isAssignmentTarget = isBindingElement = false;
+ expect(',');
+ }
+ elements.push(restSpread);
+ } else {
+ elements.push(inheritCoverGrammar(parseAssignmentExpression));
+
+ if (!match(']')) {
+ expect(',');
+ }
+ }
+ }
+
+ lex();
+
+ return node.finishArrayExpression(elements);
+ }
+
+ // ECMA-262 12.2.6 Object Initializer
+
+ function parsePropertyFunction(node, paramInfo, isGenerator) {
+ var previousStrict, body;
+
+ isAssignmentTarget = isBindingElement = false;
+
+ previousStrict = strict;
+ body = isolateCoverGrammar(parseFunctionSourceElements);
+
+ if (strict && paramInfo.firstRestricted) {
+ tolerateUnexpectedToken(paramInfo.firstRestricted, paramInfo.message);
+ }
+ if (strict && paramInfo.stricted) {
+ tolerateUnexpectedToken(paramInfo.stricted, paramInfo.message);
+ }
+
+ strict = previousStrict;
+ return node.finishFunctionExpression(null, paramInfo.params, paramInfo.defaults, body, isGenerator);
+ }
+
+ function parsePropertyMethodFunction() {
+ var params, method, node = new Node(),
+ previousAllowYield = state.allowYield;
+
+ state.allowYield = false;
+ params = parseParams();
+ state.allowYield = previousAllowYield;
+
+ state.allowYield = false;
+ method = parsePropertyFunction(node, params, false);
+ state.allowYield = previousAllowYield;
+
+ return method;
+ }
+
+ function parseObjectPropertyKey() {
+ var token, node = new Node(), expr;
+
+ token = lex();
+
+ // Note: This function is called only from parseObjectProperty(), where
+ // EOF and Punctuator tokens are already filtered out.
+
+ switch (token.type) {
+ case Token.StringLiteral:
+ case Token.NumericLiteral:
+ if (strict && token.octal) {
+ tolerateUnexpectedToken(token, Messages.StrictOctalLiteral);
+ }
+ return node.finishLiteral(token);
+ case Token.Identifier:
+ case Token.BooleanLiteral:
+ case Token.NullLiteral:
+ case Token.Keyword:
+ return node.finishIdentifier(token.value);
+ case Token.Punctuator:
+ if (token.value === '[') {
+ expr = isolateCoverGrammar(parseAssignmentExpression);
+ expect(']');
+ return expr;
+ }
+ break;
+ }
+ throwUnexpectedToken(token);
+ }
+
+ function lookaheadPropertyName() {
+ switch (lookahead.type) {
+ case Token.Identifier:
+ case Token.StringLiteral:
+ case Token.BooleanLiteral:
+ case Token.NullLiteral:
+ case Token.NumericLiteral:
+ case Token.Keyword:
+ return true;
+ case Token.Punctuator:
+ return lookahead.value === '[';
+ }
+ return false;
+ }
+
+ // This function is to try to parse a MethodDefinition as defined in 14.3. But in the case of object literals,
+ // it might be called at a position where there is in fact a short hand identifier pattern or a data property.
+ // This can only be determined after we consumed up to the left parentheses.
+ //
+ // In order to avoid back tracking, it returns `null` if the position is not a MethodDefinition and the caller
+ // is responsible to visit other options.
+ function tryParseMethodDefinition(token, key, computed, node) {
+ var value, options, methodNode, params,
+ previousAllowYield = state.allowYield;
+
+ if (token.type === Token.Identifier) {
+ // check for `get` and `set`;
+
+ if (token.value === 'get' && lookaheadPropertyName()) {
+ computed = match('[');
+ key = parseObjectPropertyKey();
+ methodNode = new Node();
+ expect('(');
+ expect(')');
+
+ state.allowYield = false;
+ value = parsePropertyFunction(methodNode, {
+ params: [],
+ defaults: [],
+ stricted: null,
+ firstRestricted: null,
+ message: null
+ }, false);
+ state.allowYield = previousAllowYield;
+
+ return node.finishProperty('get', key, computed, value, false, false);
+ } else if (token.value === 'set' && lookaheadPropertyName()) {
+ computed = match('[');
+ key = parseObjectPropertyKey();
+ methodNode = new Node();
+ expect('(');
+
+ options = {
+ params: [],
+ defaultCount: 0,
+ defaults: [],
+ firstRestricted: null,
+ paramSet: {}
+ };
+ if (match(')')) {
+ tolerateUnexpectedToken(lookahead);
+ } else {
+ state.allowYield = false;
+ parseParam(options);
+ state.allowYield = previousAllowYield;
+ if (options.defaultCount === 0) {
+ options.defaults = [];
+ }
+ }
+ expect(')');
+
+ state.allowYield = false;
+ value = parsePropertyFunction(methodNode, options, false);
+ state.allowYield = previousAllowYield;
+
+ return node.finishProperty('set', key, computed, value, false, false);
+ }
+ } else if (token.type === Token.Punctuator && token.value === '*' && lookaheadPropertyName()) {
+ computed = match('[');
+ key = parseObjectPropertyKey();
+ methodNode = new Node();
+
+ state.allowYield = true;
+ params = parseParams();
+ state.allowYield = previousAllowYield;
+
+ state.allowYield = false;
+ value = parsePropertyFunction(methodNode, params, true);
+ state.allowYield = previousAllowYield;
+
+ return node.finishProperty('init', key, computed, value, true, false);
+ }
+
+ if (key && match('(')) {
+ value = parsePropertyMethodFunction();
+ return node.finishProperty('init', key, computed, value, true, false);
+ }
+
+ // Not a MethodDefinition.
+ return null;
+ }
+
+ function parseObjectProperty(hasProto) {
+ var token = lookahead, node = new Node(), computed, key, maybeMethod, proto, value;
+
+ computed = match('[');
+ if (match('*')) {
+ lex();
+ } else {
+ key = parseObjectPropertyKey();
+ }
+ maybeMethod = tryParseMethodDefinition(token, key, computed, node);
+ if (maybeMethod) {
+ return maybeMethod;
+ }
+
+ if (!key) {
+ throwUnexpectedToken(lookahead);
+ }
+
+ // Check for duplicated __proto__
+ if (!computed) {
+ proto = (key.type === Syntax.Identifier && key.name === '__proto__') ||
+ (key.type === Syntax.Literal && key.value === '__proto__');
+ if (hasProto.value && proto) {
+ tolerateError(Messages.DuplicateProtoProperty);
+ }
+ hasProto.value |= proto;
+ }
+
+ if (match(':')) {
+ lex();
+ value = inheritCoverGrammar(parseAssignmentExpression);
+ return node.finishProperty('init', key, computed, value, false, false);
+ }
+
+ if (token.type === Token.Identifier) {
+ if (match('=')) {
+ firstCoverInitializedNameError = lookahead;
+ lex();
+ value = isolateCoverGrammar(parseAssignmentExpression);
+ return node.finishProperty('init', key, computed,
+ new WrappingNode(token).finishAssignmentPattern(key, value), false, true);
+ }
+ return node.finishProperty('init', key, computed, key, false, true);
+ }
+
+ throwUnexpectedToken(lookahead);
+ }
+
+ function parseObjectInitializer() {
+ var properties = [], hasProto = {value: false}, node = new Node();
+
+ expect('{');
+
+ while (!match('}')) {
+ properties.push(parseObjectProperty(hasProto));
+
+ if (!match('}')) {
+ expectCommaSeparator();
+ }
+ }
+
+ expect('}');
+
+ return node.finishObjectExpression(properties);
+ }
+
+ function reinterpretExpressionAsPattern(expr) {
+ var i;
+ switch (expr.type) {
+ case Syntax.Identifier:
+ case Syntax.MemberExpression:
+ case Syntax.RestElement:
+ case Syntax.AssignmentPattern:
+ break;
+ case Syntax.SpreadElement:
+ expr.type = Syntax.RestElement;
+ reinterpretExpressionAsPattern(expr.argument);
+ break;
+ case Syntax.ArrayExpression:
+ expr.type = Syntax.ArrayPattern;
+ for (i = 0; i < expr.elements.length; i++) {
+ if (expr.elements[i] !== null) {
+ reinterpretExpressionAsPattern(expr.elements[i]);
+ }
+ }
+ break;
+ case Syntax.ObjectExpression:
+ expr.type = Syntax.ObjectPattern;
+ for (i = 0; i < expr.properties.length; i++) {
+ reinterpretExpressionAsPattern(expr.properties[i].value);
+ }
+ break;
+ case Syntax.AssignmentExpression:
+ expr.type = Syntax.AssignmentPattern;
+ reinterpretExpressionAsPattern(expr.left);
+ break;
+ default:
+ // Allow other node type for tolerant parsing.
+ break;
+ }
+ }
+
+ // ECMA-262 12.2.9 Template Literals
+
+ function parseTemplateElement(option) {
+ var node, token;
+
+ if (lookahead.type !== Token.Template || (option.head && !lookahead.head)) {
+ throwUnexpectedToken();
+ }
+
+ node = new Node();
+ token = lex();
+
+ return node.finishTemplateElement({ raw: token.value.raw, cooked: token.value.cooked }, token.tail);
+ }
+
+ function parseTemplateLiteral() {
+ var quasi, quasis, expressions, node = new Node();
+
+ quasi = parseTemplateElement({ head: true });
+ quasis = [quasi];
+ expressions = [];
+
+ while (!quasi.tail) {
+ expressions.push(parseExpression());
+ quasi = parseTemplateElement({ head: false });
+ quasis.push(quasi);
+ }
+
+ return node.finishTemplateLiteral(quasis, expressions);
+ }
+
+ // ECMA-262 12.2.10 The Grouping Operator
+
+ function parseGroupExpression() {
+ var expr, expressions, startToken, i, params = [];
+
+ expect('(');
+
+ if (match(')')) {
+ lex();
+ if (!match('=>')) {
+ expect('=>');
+ }
+ return {
+ type: PlaceHolders.ArrowParameterPlaceHolder,
+ params: [],
+ rawParams: []
+ };
+ }
+
+ startToken = lookahead;
+ if (match('...')) {
+ expr = parseRestElement(params);
+ expect(')');
+ if (!match('=>')) {
+ expect('=>');
+ }
+ return {
+ type: PlaceHolders.ArrowParameterPlaceHolder,
+ params: [expr]
+ };
+ }
+
+ isBindingElement = true;
+ expr = inheritCoverGrammar(parseAssignmentExpression);
+
+ if (match(',')) {
+ isAssignmentTarget = false;
+ expressions = [expr];
+
+ while (startIndex < length) {
+ if (!match(',')) {
+ break;
+ }
+ lex();
+
+ if (match('...')) {
+ if (!isBindingElement) {
+ throwUnexpectedToken(lookahead);
+ }
+ expressions.push(parseRestElement(params));
+ expect(')');
+ if (!match('=>')) {
+ expect('=>');
+ }
+ isBindingElement = false;
+ for (i = 0; i < expressions.length; i++) {
+ reinterpretExpressionAsPattern(expressions[i]);
+ }
+ return {
+ type: PlaceHolders.ArrowParameterPlaceHolder,
+ params: expressions
+ };
+ }
+
+ expressions.push(inheritCoverGrammar(parseAssignmentExpression));
+ }
+
+ expr = new WrappingNode(startToken).finishSequenceExpression(expressions);
+ }
+
+
+ expect(')');
+
+ if (match('=>')) {
+ if (expr.type === Syntax.Identifier && expr.name === 'yield') {
+ return {
+ type: PlaceHolders.ArrowParameterPlaceHolder,
+ params: [expr]
+ };
+ }
+
+ if (!isBindingElement) {
+ throwUnexpectedToken(lookahead);
+ }
+
+ if (expr.type === Syntax.SequenceExpression) {
+ for (i = 0; i < expr.expressions.length; i++) {
+ reinterpretExpressionAsPattern(expr.expressions[i]);
+ }
+ } else {
+ reinterpretExpressionAsPattern(expr);
+ }
+
+ expr = {
+ type: PlaceHolders.ArrowParameterPlaceHolder,
+ params: expr.type === Syntax.SequenceExpression ? expr.expressions : [expr]
+ };
+ }
+ isBindingElement = false;
+ return expr;
+ }
+
+
+ // ECMA-262 12.2 Primary Expressions
+
+ function parsePrimaryExpression() {
+ var type, token, expr, node;
+
+ if (match('(')) {
+ isBindingElement = false;
+ return inheritCoverGrammar(parseGroupExpression);
+ }
+
+ if (match('[')) {
+ return inheritCoverGrammar(parseArrayInitializer);
+ }
+
+ if (match('{')) {
+ return inheritCoverGrammar(parseObjectInitializer);
+ }
+
+ type = lookahead.type;
+ node = new Node();
+
+ if (type === Token.Identifier) {
+ if (state.sourceType === 'module' && lookahead.value === 'await') {
+ tolerateUnexpectedToken(lookahead);
+ }
+ expr = node.finishIdentifier(lex().value);
+ } else if (type === Token.StringLiteral || type === Token.NumericLiteral) {
+ isAssignmentTarget = isBindingElement = false;
+ if (strict && lookahead.octal) {
+ tolerateUnexpectedToken(lookahead, Messages.StrictOctalLiteral);
+ }
+ expr = node.finishLiteral(lex());
+ } else if (type === Token.Keyword) {
+ if (!strict && state.allowYield && matchKeyword('yield')) {
+ return parseNonComputedProperty();
+ }
+ if (!strict && matchKeyword('let')) {
+ return node.finishIdentifier(lex().value);
+ }
+ isAssignmentTarget = isBindingElement = false;
+ if (matchKeyword('function')) {
+ return parseFunctionExpression();
+ }
+ if (matchKeyword('this')) {
+ lex();
+ return node.finishThisExpression();
+ }
+ if (matchKeyword('class')) {
+ return parseClassExpression();
+ }
+ throwUnexpectedToken(lex());
+ } else if (type === Token.BooleanLiteral) {
+ isAssignmentTarget = isBindingElement = false;
+ token = lex();
+ token.value = (token.value === 'true');
+ expr = node.finishLiteral(token);
+ } else if (type === Token.NullLiteral) {
+ isAssignmentTarget = isBindingElement = false;
+ token = lex();
+ token.value = null;
+ expr = node.finishLiteral(token);
+ } else if (match('/') || match('/=')) {
+ isAssignmentTarget = isBindingElement = false;
+ index = startIndex;
+
+ if (typeof extra.tokens !== 'undefined') {
+ token = collectRegex();
+ } else {
+ token = scanRegExp();
+ }
+ lex();
+ expr = node.finishLiteral(token);
+ } else if (type === Token.Template) {
+ expr = parseTemplateLiteral();
+ } else {
+ throwUnexpectedToken(lex());
+ }
+
+ return expr;
+ }
+
+ // ECMA-262 12.3 Left-Hand-Side Expressions
+
+ function parseArguments() {
+ var args = [], expr;
+
+ expect('(');
+
+ if (!match(')')) {
+ while (startIndex < length) {
+ if (match('...')) {
+ expr = new Node();
+ lex();
+ expr.finishSpreadElement(isolateCoverGrammar(parseAssignmentExpression));
+ } else {
+ expr = isolateCoverGrammar(parseAssignmentExpression);
+ }
+ args.push(expr);
+ if (match(')')) {
+ break;
+ }
+ expectCommaSeparator();
+ }
+ }
+
+ expect(')');
+
+ return args;
+ }
+
+ function parseNonComputedProperty() {
+ var token, node = new Node();
+
+ token = lex();
+
+ if (!isIdentifierName(token)) {
+ throwUnexpectedToken(token);
+ }
+
+ return node.finishIdentifier(token.value);
+ }
+
+ function parseNonComputedMember() {
+ expect('.');
+
+ return parseNonComputedProperty();
+ }
+
+ function parseComputedMember() {
+ var expr;
+
+ expect('[');
+
+ expr = isolateCoverGrammar(parseExpression);
+
+ expect(']');
+
+ return expr;
+ }
+
+ // ECMA-262 12.3.3 The new Operator
+
+ function parseNewExpression() {
+ var callee, args, node = new Node();
+
+ expectKeyword('new');
+
+ if (match('.')) {
+ lex();
+ if (lookahead.type === Token.Identifier && lookahead.value === 'target') {
+ if (state.inFunctionBody) {
+ lex();
+ return node.finishMetaProperty('new', 'target');
+ }
+ }
+ throwUnexpectedToken(lookahead);
+ }
+
+ callee = isolateCoverGrammar(parseLeftHandSideExpression);
+ args = match('(') ? parseArguments() : [];
+
+ isAssignmentTarget = isBindingElement = false;
+
+ return node.finishNewExpression(callee, args);
+ }
+
+ // ECMA-262 12.3.4 Function Calls
+
+ function parseLeftHandSideExpressionAllowCall() {
+ var quasi, expr, args, property, startToken, previousAllowIn = state.allowIn;
+
+ startToken = lookahead;
+ state.allowIn = true;
+
+ if (matchKeyword('super') && state.inFunctionBody) {
+ expr = new Node();
+ lex();
+ expr = expr.finishSuper();
+ if (!match('(') && !match('.') && !match('[')) {
+ throwUnexpectedToken(lookahead);
+ }
+ } else {
+ expr = inheritCoverGrammar(matchKeyword('new') ? parseNewExpression : parsePrimaryExpression);
+ }
+
+ for (;;) {
+ if (match('.')) {
+ isBindingElement = false;
+ isAssignmentTarget = true;
+ property = parseNonComputedMember();
+ expr = new WrappingNode(startToken).finishMemberExpression('.', expr, property);
+ } else if (match('(')) {
+ isBindingElement = false;
+ isAssignmentTarget = false;
+ args = parseArguments();
+ expr = new WrappingNode(startToken).finishCallExpression(expr, args);
+ } else if (match('[')) {
+ isBindingElement = false;
+ isAssignmentTarget = true;
+ property = parseComputedMember();
+ expr = new WrappingNode(startToken).finishMemberExpression('[', expr, property);
+ } else if (lookahead.type === Token.Template && lookahead.head) {
+ quasi = parseTemplateLiteral();
+ expr = new WrappingNode(startToken).finishTaggedTemplateExpression(expr, quasi);
+ } else {
+ break;
+ }
+ }
+ state.allowIn = previousAllowIn;
+
+ return expr;
+ }
+
+ // ECMA-262 12.3 Left-Hand-Side Expressions
+
+ function parseLeftHandSideExpression() {
+ var quasi, expr, property, startToken;
+ assert(state.allowIn, 'callee of new expression always allow in keyword.');
+
+ startToken = lookahead;
+
+ if (matchKeyword('super') && state.inFunctionBody) {
+ expr = new Node();
+ lex();
+ expr = expr.finishSuper();
+ if (!match('[') && !match('.')) {
+ throwUnexpectedToken(lookahead);
+ }
+ } else {
+ expr = inheritCoverGrammar(matchKeyword('new') ? parseNewExpression : parsePrimaryExpression);
+ }
+
+ for (;;) {
+ if (match('[')) {
+ isBindingElement = false;
+ isAssignmentTarget = true;
+ property = parseComputedMember();
+ expr = new WrappingNode(startToken).finishMemberExpression('[', expr, property);
+ } else if (match('.')) {
+ isBindingElement = false;
+ isAssignmentTarget = true;
+ property = parseNonComputedMember();
+ expr = new WrappingNode(startToken).finishMemberExpression('.', expr, property);
+ } else if (lookahead.type === Token.Template && lookahead.head) {
+ quasi = parseTemplateLiteral();
+ expr = new WrappingNode(startToken).finishTaggedTemplateExpression(expr, quasi);
+ } else {
+ break;
+ }
+ }
+ return expr;
+ }
+
+ // ECMA-262 12.4 Postfix Expressions
+
+ function parsePostfixExpression() {
+ var expr, token, startToken = lookahead;
+
+ expr = inheritCoverGrammar(parseLeftHandSideExpressionAllowCall);
+
+ if (!hasLineTerminator && lookahead.type === Token.Punctuator) {
+ if (match('++') || match('--')) {
+ // ECMA-262 11.3.1, 11.3.2
+ if (strict && expr.type === Syntax.Identifier && isRestrictedWord(expr.name)) {
+ tolerateError(Messages.StrictLHSPostfix);
+ }
+
+ if (!isAssignmentTarget) {
+ tolerateError(Messages.InvalidLHSInAssignment);
+ }
+
+ isAssignmentTarget = isBindingElement = false;
+
+ token = lex();
+ expr = new WrappingNode(startToken).finishPostfixExpression(token.value, expr);
+ }
+ }
+
+ return expr;
+ }
+
+ // ECMA-262 12.5 Unary Operators
+
+ function parseUnaryExpression() {
+ var token, expr, startToken;
+
+ if (lookahead.type !== Token.Punctuator && lookahead.type !== Token.Keyword) {
+ expr = parsePostfixExpression();
+ } else if (match('++') || match('--')) {
+ startToken = lookahead;
+ token = lex();
+ expr = inheritCoverGrammar(parseUnaryExpression);
+ // ECMA-262 11.4.4, 11.4.5
+ if (strict && expr.type === Syntax.Identifier && isRestrictedWord(expr.name)) {
+ tolerateError(Messages.StrictLHSPrefix);
+ }
+
+ if (!isAssignmentTarget) {
+ tolerateError(Messages.InvalidLHSInAssignment);
+ }
+ expr = new WrappingNode(startToken).finishUnaryExpression(token.value, expr);
+ isAssignmentTarget = isBindingElement = false;
+ } else if (match('+') || match('-') || match('~') || match('!')) {
+ startToken = lookahead;
+ token = lex();
+ expr = inheritCoverGrammar(parseUnaryExpression);
+ expr = new WrappingNode(startToken).finishUnaryExpression(token.value, expr);
+ isAssignmentTarget = isBindingElement = false;
+ } else if (matchKeyword('delete') || matchKeyword('void') || matchKeyword('typeof')) {
+ startToken = lookahead;
+ token = lex();
+ expr = inheritCoverGrammar(parseUnaryExpression);
+ expr = new WrappingNode(startToken).finishUnaryExpression(token.value, expr);
+ if (strict && expr.operator === 'delete' && expr.argument.type === Syntax.Identifier) {
+ tolerateError(Messages.StrictDelete);
+ }
+ isAssignmentTarget = isBindingElement = false;
+ } else {
+ expr = parsePostfixExpression();
+ }
+
+ return expr;
+ }
+
+ function binaryPrecedence(token, allowIn) {
+ var prec = 0;
+
+ if (token.type !== Token.Punctuator && token.type !== Token.Keyword) {
+ return 0;
+ }
+
+ switch (token.value) {
+ case '||':
+ prec = 1;
+ break;
+
+ case '&&':
+ prec = 2;
+ break;
+
+ case '|':
+ prec = 3;
+ break;
+
+ case '^':
+ prec = 4;
+ break;
+
+ case '&':
+ prec = 5;
+ break;
+
+ case '==':
+ case '!=':
+ case '===':
+ case '!==':
+ prec = 6;
+ break;
+
+ case '<':
+ case '>':
+ case '<=':
+ case '>=':
+ case 'instanceof':
+ prec = 7;
+ break;
+
+ case 'in':
+ prec = allowIn ? 7 : 0;
+ break;
+
+ case '<<':
+ case '>>':
+ case '>>>':
+ prec = 8;
+ break;
+
+ case '+':
+ case '-':
+ prec = 9;
+ break;
+
+ case '*':
+ case '/':
+ case '%':
+ prec = 11;
+ break;
+
+ default:
+ break;
+ }
+
+ return prec;
+ }
+
+ // ECMA-262 12.6 Multiplicative Operators
+ // ECMA-262 12.7 Additive Operators
+ // ECMA-262 12.8 Bitwise Shift Operators
+ // ECMA-262 12.9 Relational Operators
+ // ECMA-262 12.10 Equality Operators
+ // ECMA-262 12.11 Binary Bitwise Operators
+ // ECMA-262 12.12 Binary Logical Operators
+
+ function parseBinaryExpression() {
+ var marker, markers, expr, token, prec, stack, right, operator, left, i;
+
+ marker = lookahead;
+ left = inheritCoverGrammar(parseUnaryExpression);
+
+ token = lookahead;
+ prec = binaryPrecedence(token, state.allowIn);
+ if (prec === 0) {
+ return left;
+ }
+ isAssignmentTarget = isBindingElement = false;
+ token.prec = prec;
+ lex();
+
+ markers = [marker, lookahead];
+ right = isolateCoverGrammar(parseUnaryExpression);
+
+ stack = [left, token, right];
+
+ while ((prec = binaryPrecedence(lookahead, state.allowIn)) > 0) {
+
+ // Reduce: make a binary expression from the three topmost entries.
+ while ((stack.length > 2) && (prec <= stack[stack.length - 2].prec)) {
+ right = stack.pop();
+ operator = stack.pop().value;
+ left = stack.pop();
+ markers.pop();
+ expr = new WrappingNode(markers[markers.length - 1]).finishBinaryExpression(operator, left, right);
+ stack.push(expr);
+ }
+
+ // Shift.
+ token = lex();
+ token.prec = prec;
+ stack.push(token);
+ markers.push(lookahead);
+ expr = isolateCoverGrammar(parseUnaryExpression);
+ stack.push(expr);
+ }
+
+ // Final reduce to clean-up the stack.
+ i = stack.length - 1;
+ expr = stack[i];
+ markers.pop();
+ while (i > 1) {
+ expr = new WrappingNode(markers.pop()).finishBinaryExpression(stack[i - 1].value, stack[i - 2], expr);
+ i -= 2;
+ }
+
+ return expr;
+ }
+
+
+ // ECMA-262 12.13 Conditional Operator
+
+ function parseConditionalExpression() {
+ var expr, previousAllowIn, consequent, alternate, startToken;
+
+ startToken = lookahead;
+
+ expr = inheritCoverGrammar(parseBinaryExpression);
+ if (match('?')) {
+ lex();
+ previousAllowIn = state.allowIn;
+ state.allowIn = true;
+ consequent = isolateCoverGrammar(parseAssignmentExpression);
+ state.allowIn = previousAllowIn;
+ expect(':');
+ alternate = isolateCoverGrammar(parseAssignmentExpression);
+
+ expr = new WrappingNode(startToken).finishConditionalExpression(expr, consequent, alternate);
+ isAssignmentTarget = isBindingElement = false;
+ }
+
+ return expr;
+ }
+
+ // ECMA-262 14.2 Arrow Function Definitions
+
+ function parseConciseBody() {
+ if (match('{')) {
+ return parseFunctionSourceElements();
+ }
+ return isolateCoverGrammar(parseAssignmentExpression);
+ }
+
+ function checkPatternParam(options, param) {
+ var i;
+ switch (param.type) {
+ case Syntax.Identifier:
+ validateParam(options, param, param.name);
+ break;
+ case Syntax.RestElement:
+ checkPatternParam(options, param.argument);
+ break;
+ case Syntax.AssignmentPattern:
+ checkPatternParam(options, param.left);
+ break;
+ case Syntax.ArrayPattern:
+ for (i = 0; i < param.elements.length; i++) {
+ if (param.elements[i] !== null) {
+ checkPatternParam(options, param.elements[i]);
+ }
+ }
+ break;
+ case Syntax.YieldExpression:
+ break;
+ default:
+ assert(param.type === Syntax.ObjectPattern, 'Invalid type');
+ for (i = 0; i < param.properties.length; i++) {
+ checkPatternParam(options, param.properties[i].value);
+ }
+ break;
+ }
+ }
+ function reinterpretAsCoverFormalsList(expr) {
+ var i, len, param, params, defaults, defaultCount, options, token;
+
+ defaults = [];
+ defaultCount = 0;
+ params = [expr];
+
+ switch (expr.type) {
+ case Syntax.Identifier:
+ break;
+ case PlaceHolders.ArrowParameterPlaceHolder:
+ params = expr.params;
+ break;
+ default:
+ return null;
+ }
+
+ options = {
+ paramSet: {}
+ };
+
+ for (i = 0, len = params.length; i < len; i += 1) {
+ param = params[i];
+ switch (param.type) {
+ case Syntax.AssignmentPattern:
+ params[i] = param.left;
+ if (param.right.type === Syntax.YieldExpression) {
+ if (param.right.argument) {
+ throwUnexpectedToken(lookahead);
+ }
+ param.right.type = Syntax.Identifier;
+ param.right.name = 'yield';
+ delete param.right.argument;
+ delete param.right.delegate;
+ }
+ defaults.push(param.right);
+ ++defaultCount;
+ checkPatternParam(options, param.left);
+ break;
+ default:
+ checkPatternParam(options, param);
+ params[i] = param;
+ defaults.push(null);
+ break;
+ }
+ }
+
+ if (strict || !state.allowYield) {
+ for (i = 0, len = params.length; i < len; i += 1) {
+ param = params[i];
+ if (param.type === Syntax.YieldExpression) {
+ throwUnexpectedToken(lookahead);
+ }
+ }
+ }
+
+ if (options.message === Messages.StrictParamDupe) {
+ token = strict ? options.stricted : options.firstRestricted;
+ throwUnexpectedToken(token, options.message);
+ }
+
+ if (defaultCount === 0) {
+ defaults = [];
+ }
+
+ return {
+ params: params,
+ defaults: defaults,
+ stricted: options.stricted,
+ firstRestricted: options.firstRestricted,
+ message: options.message
+ };
+ }
+
+ function parseArrowFunctionExpression(options, node) {
+ var previousStrict, previousAllowYield, body;
+
+ if (hasLineTerminator) {
+ tolerateUnexpectedToken(lookahead);
+ }
+ expect('=>');
+
+ previousStrict = strict;
+ previousAllowYield = state.allowYield;
+ state.allowYield = true;
+
+ body = parseConciseBody();
+
+ if (strict && options.firstRestricted) {
+ throwUnexpectedToken(options.firstRestricted, options.message);
+ }
+ if (strict && options.stricted) {
+ tolerateUnexpectedToken(options.stricted, options.message);
+ }
+
+ strict = previousStrict;
+ state.allowYield = previousAllowYield;
+
+ return node.finishArrowFunctionExpression(options.params, options.defaults, body, body.type !== Syntax.BlockStatement);
+ }
+
+ // ECMA-262 14.4 Yield expression
+
+ function parseYieldExpression() {
+ var argument, expr, delegate, previousAllowYield;
+
+ argument = null;
+ expr = new Node();
+ delegate = false;
+
+ expectKeyword('yield');
+
+ if (!hasLineTerminator) {
+ previousAllowYield = state.allowYield;
+ state.allowYield = false;
+ delegate = match('*');
+ if (delegate) {
+ lex();
+ argument = parseAssignmentExpression();
+ } else {
+ if (!match(';') && !match('}') && !match(')') && lookahead.type !== Token.EOF) {
+ argument = parseAssignmentExpression();
+ }
+ }
+ state.allowYield = previousAllowYield;
+ }
+
+ return expr.finishYieldExpression(argument, delegate);
+ }
+
+ // ECMA-262 12.14 Assignment Operators
+
+ function parseAssignmentExpression() {
+ var token, expr, right, list, startToken;
+
+ startToken = lookahead;
+ token = lookahead;
+
+ if (!state.allowYield && matchKeyword('yield')) {
+ return parseYieldExpression();
+ }
+
+ expr = parseConditionalExpression();
+
+ if (expr.type === PlaceHolders.ArrowParameterPlaceHolder || match('=>')) {
+ isAssignmentTarget = isBindingElement = false;
+ list = reinterpretAsCoverFormalsList(expr);
+
+ if (list) {
+ firstCoverInitializedNameError = null;
+ return parseArrowFunctionExpression(list, new WrappingNode(startToken));
+ }
+
+ return expr;
+ }
+
+ if (matchAssign()) {
+ if (!isAssignmentTarget) {
+ tolerateError(Messages.InvalidLHSInAssignment);
+ }
+
+ // ECMA-262 12.1.1
+ if (strict && expr.type === Syntax.Identifier) {
+ if (isRestrictedWord(expr.name)) {
+ tolerateUnexpectedToken(token, Messages.StrictLHSAssignment);
+ }
+ if (isStrictModeReservedWord(expr.name)) {
+ tolerateUnexpectedToken(token, Messages.StrictReservedWord);
+ }
+ }
+
+ if (!match('=')) {
+ isAssignmentTarget = isBindingElement = false;
+ } else {
+ reinterpretExpressionAsPattern(expr);
+ }
+
+ token = lex();
+ right = isolateCoverGrammar(parseAssignmentExpression);
+ expr = new WrappingNode(startToken).finishAssignmentExpression(token.value, expr, right);
+ firstCoverInitializedNameError = null;
+ }
+
+ return expr;
+ }
+
+ // ECMA-262 12.15 Comma Operator
+
+ function parseExpression() {
+ var expr, startToken = lookahead, expressions;
+
+ expr = isolateCoverGrammar(parseAssignmentExpression);
+
+ if (match(',')) {
+ expressions = [expr];
+
+ while (startIndex < length) {
+ if (!match(',')) {
+ break;
+ }
+ lex();
+ expressions.push(isolateCoverGrammar(parseAssignmentExpression));
+ }
+
+ expr = new WrappingNode(startToken).finishSequenceExpression(expressions);
+ }
+
+ return expr;
+ }
+
+ // ECMA-262 13.2 Block
+
+ function parseStatementListItem() {
+ if (lookahead.type === Token.Keyword) {
+ switch (lookahead.value) {
+ case 'export':
+ if (state.sourceType !== 'module') {
+ tolerateUnexpectedToken(lookahead, Messages.IllegalExportDeclaration);
+ }
+ return parseExportDeclaration();
+ case 'import':
+ if (state.sourceType !== 'module') {
+ tolerateUnexpectedToken(lookahead, Messages.IllegalImportDeclaration);
+ }
+ return parseImportDeclaration();
+ case 'const':
+ return parseLexicalDeclaration({inFor: false});
+ case 'function':
+ return parseFunctionDeclaration(new Node());
+ case 'class':
+ return parseClassDeclaration();
+ }
+ }
+
+ if (matchKeyword('let') && isLexicalDeclaration()) {
+ return parseLexicalDeclaration({inFor: false});
+ }
+
+ return parseStatement();
+ }
+
+ function parseStatementList() {
+ var list = [];
+ while (startIndex < length) {
+ if (match('}')) {
+ break;
+ }
+ list.push(parseStatementListItem());
+ }
+
+ return list;
+ }
+
+ function parseBlock() {
+ var block, node = new Node();
+
+ expect('{');
+
+ block = parseStatementList();
+
+ expect('}');
+
+ return node.finishBlockStatement(block);
+ }
+
+ // ECMA-262 13.3.2 Variable Statement
+
+ function parseVariableIdentifier(kind) {
+ var token, node = new Node();
+
+ token = lex();
+
+ if (token.type === Token.Keyword && token.value === 'yield') {
+ if (strict) {
+ tolerateUnexpectedToken(token, Messages.StrictReservedWord);
+ } if (!state.allowYield) {
+ throwUnexpectedToken(token);
+ }
+ } else if (token.type !== Token.Identifier) {
+ if (strict && token.type === Token.Keyword && isStrictModeReservedWord(token.value)) {
+ tolerateUnexpectedToken(token, Messages.StrictReservedWord);
+ } else {
+ if (strict || token.value !== 'let' || kind !== 'var') {
+ throwUnexpectedToken(token);
+ }
+ }
+ } else if (state.sourceType === 'module' && token.type === Token.Identifier && token.value === 'await') {
+ tolerateUnexpectedToken(token);
+ }
+
+ return node.finishIdentifier(token.value);
+ }
+
+ function parseVariableDeclaration(options) {
+ var init = null, id, node = new Node(), params = [];
+
+ id = parsePattern(params, 'var');
+
+ // ECMA-262 12.2.1
+ if (strict && isRestrictedWord(id.name)) {
+ tolerateError(Messages.StrictVarName);
+ }
+
+ if (match('=')) {
+ lex();
+ init = isolateCoverGrammar(parseAssignmentExpression);
+ } else if (id.type !== Syntax.Identifier && !options.inFor) {
+ expect('=');
+ }
+
+ return node.finishVariableDeclarator(id, init);
+ }
+
+ function parseVariableDeclarationList(options) {
+ var opt, list;
+
+ opt = { inFor: options.inFor };
+ list = [parseVariableDeclaration(opt)];
+
+ while (match(',')) {
+ lex();
+ list.push(parseVariableDeclaration(opt));
+ }
+
+ return list;
+ }
+
+ function parseVariableStatement(node) {
+ var declarations;
+
+ expectKeyword('var');
+
+ declarations = parseVariableDeclarationList({ inFor: false });
+
+ consumeSemicolon();
+
+ return node.finishVariableDeclaration(declarations);
+ }
+
+ // ECMA-262 13.3.1 Let and Const Declarations
+
+ function parseLexicalBinding(kind, options) {
+ var init = null, id, node = new Node(), params = [];
+
+ id = parsePattern(params, kind);
+
+ // ECMA-262 12.2.1
+ if (strict && id.type === Syntax.Identifier && isRestrictedWord(id.name)) {
+ tolerateError(Messages.StrictVarName);
+ }
+
+ if (kind === 'const') {
+ if (!matchKeyword('in') && !matchContextualKeyword('of')) {
+ expect('=');
+ init = isolateCoverGrammar(parseAssignmentExpression);
+ }
+ } else if ((!options.inFor && id.type !== Syntax.Identifier) || match('=')) {
+ expect('=');
+ init = isolateCoverGrammar(parseAssignmentExpression);
+ }
+
+ return node.finishVariableDeclarator(id, init);
+ }
+
+ function parseBindingList(kind, options) {
+ var list = [parseLexicalBinding(kind, options)];
+
+ while (match(',')) {
+ lex();
+ list.push(parseLexicalBinding(kind, options));
+ }
+
+ return list;
+ }
+
+
+ function tokenizerState() {
+ return {
+ index: index,
+ lineNumber: lineNumber,
+ lineStart: lineStart,
+ hasLineTerminator: hasLineTerminator,
+ lastIndex: lastIndex,
+ lastLineNumber: lastLineNumber,
+ lastLineStart: lastLineStart,
+ startIndex: startIndex,
+ startLineNumber: startLineNumber,
+ startLineStart: startLineStart,
+ lookahead: lookahead,
+ tokenCount: extra.tokens ? extra.tokens.length : 0
+ };
+ }
+
+ function resetTokenizerState(ts) {
+ index = ts.index;
+ lineNumber = ts.lineNumber;
+ lineStart = ts.lineStart;
+ hasLineTerminator = ts.hasLineTerminator;
+ lastIndex = ts.lastIndex;
+ lastLineNumber = ts.lastLineNumber;
+ lastLineStart = ts.lastLineStart;
+ startIndex = ts.startIndex;
+ startLineNumber = ts.startLineNumber;
+ startLineStart = ts.startLineStart;
+ lookahead = ts.lookahead;
+ if (extra.tokens) {
+ extra.tokens.splice(ts.tokenCount, extra.tokens.length);
+ }
+ }
+
+ function isLexicalDeclaration() {
+ var lexical, ts;
+
+ ts = tokenizerState();
+
+ lex();
+ lexical = (lookahead.type === Token.Identifier) || match('[') || match('{') ||
+ matchKeyword('let') || matchKeyword('yield');
+
+ resetTokenizerState(ts);
+
+ return lexical;
+ }
+
+ function parseLexicalDeclaration(options) {
+ var kind, declarations, node = new Node();
+
+ kind = lex().value;
+ assert(kind === 'let' || kind === 'const', 'Lexical declaration must be either let or const');
+
+ declarations = parseBindingList(kind, options);
+
+ consumeSemicolon();
+
+ return node.finishLexicalDeclaration(declarations, kind);
+ }
+
+ function parseRestElement(params) {
+ var param, node = new Node();
+
+ lex();
+
+ if (match('{')) {
+ throwError(Messages.ObjectPatternAsRestParameter);
+ }
+
+ params.push(lookahead);
+
+ param = parseVariableIdentifier();
+
+ if (match('=')) {
+ throwError(Messages.DefaultRestParameter);
+ }
+
+ if (!match(')')) {
+ throwError(Messages.ParameterAfterRestParameter);
+ }
+
+ return node.finishRestElement(param);
+ }
+
+ // ECMA-262 13.4 Empty Statement
+
+ function parseEmptyStatement(node) {
+ expect(';');
+ return node.finishEmptyStatement();
+ }
+
+ // ECMA-262 12.4 Expression Statement
+
+ function parseExpressionStatement(node) {
+ var expr = parseExpression();
+ consumeSemicolon();
+ return node.finishExpressionStatement(expr);
+ }
+
+ // ECMA-262 13.6 If statement
+
+ function parseIfStatement(node) {
+ var test, consequent, alternate;
+
+ expectKeyword('if');
+
+ expect('(');
+
+ test = parseExpression();
+
+ expect(')');
+
+ consequent = parseStatement();
+
+ if (matchKeyword('else')) {
+ lex();
+ alternate = parseStatement();
+ } else {
+ alternate = null;
+ }
+
+ return node.finishIfStatement(test, consequent, alternate);
+ }
+
+ // ECMA-262 13.7 Iteration Statements
+
+ function parseDoWhileStatement(node) {
+ var body, test, oldInIteration;
+
+ expectKeyword('do');
+
+ oldInIteration = state.inIteration;
+ state.inIteration = true;
+
+ body = parseStatement();
+
+ state.inIteration = oldInIteration;
+
+ expectKeyword('while');
+
+ expect('(');
+
+ test = parseExpression();
+
+ expect(')');
+
+ if (match(';')) {
+ lex();
+ }
+
+ return node.finishDoWhileStatement(body, test);
+ }
+
+ function parseWhileStatement(node) {
+ var test, body, oldInIteration;
+
+ expectKeyword('while');
+
+ expect('(');
+
+ test = parseExpression();
+
+ expect(')');
+
+ oldInIteration = state.inIteration;
+ state.inIteration = true;
+
+ body = parseStatement();
+
+ state.inIteration = oldInIteration;
+
+ return node.finishWhileStatement(test, body);
+ }
+
+ function parseForStatement(node) {
+ var init, forIn, initSeq, initStartToken, test, update, left, right, kind, declarations,
+ body, oldInIteration, previousAllowIn = state.allowIn;
+
+ init = test = update = null;
+ forIn = true;
+
+ expectKeyword('for');
+
+ expect('(');
+
+ if (match(';')) {
+ lex();
+ } else {
+ if (matchKeyword('var')) {
+ init = new Node();
+ lex();
+
+ state.allowIn = false;
+ declarations = parseVariableDeclarationList({ inFor: true });
+ state.allowIn = previousAllowIn;
+
+ if (declarations.length === 1 && matchKeyword('in')) {
+ init = init.finishVariableDeclaration(declarations);
+ lex();
+ left = init;
+ right = parseExpression();
+ init = null;
+ } else if (declarations.length === 1 && declarations[0].init === null && matchContextualKeyword('of')) {
+ init = init.finishVariableDeclaration(declarations);
+ lex();
+ left = init;
+ right = parseAssignmentExpression();
+ init = null;
+ forIn = false;
+ } else {
+ init = init.finishVariableDeclaration(declarations);
+ expect(';');
+ }
+ } else if (matchKeyword('const') || matchKeyword('let')) {
+ init = new Node();
+ kind = lex().value;
+
+ if (!strict && lookahead.value === 'in') {
+ init = init.finishIdentifier(kind);
+ lex();
+ left = init;
+ right = parseExpression();
+ init = null;
+ } else {
+ state.allowIn = false;
+ declarations = parseBindingList(kind, {inFor: true});
+ state.allowIn = previousAllowIn;
+
+ if (declarations.length === 1 && declarations[0].init === null && matchKeyword('in')) {
+ init = init.finishLexicalDeclaration(declarations, kind);
+ lex();
+ left = init;
+ right = parseExpression();
+ init = null;
+ } else if (declarations.length === 1 && declarations[0].init === null && matchContextualKeyword('of')) {
+ init = init.finishLexicalDeclaration(declarations, kind);
+ lex();
+ left = init;
+ right = parseAssignmentExpression();
+ init = null;
+ forIn = false;
+ } else {
+ consumeSemicolon();
+ init = init.finishLexicalDeclaration(declarations, kind);
+ }
+ }
+ } else {
+ initStartToken = lookahead;
+ state.allowIn = false;
+ init = inheritCoverGrammar(parseAssignmentExpression);
+ state.allowIn = previousAllowIn;
+
+ if (matchKeyword('in')) {
+ if (!isAssignmentTarget) {
+ tolerateError(Messages.InvalidLHSInForIn);
+ }
+
+ lex();
+ reinterpretExpressionAsPattern(init);
+ left = init;
+ right = parseExpression();
+ init = null;
+ } else if (matchContextualKeyword('of')) {
+ if (!isAssignmentTarget) {
+ tolerateError(Messages.InvalidLHSInForLoop);
+ }
+
+ lex();
+ reinterpretExpressionAsPattern(init);
+ left = init;
+ right = parseAssignmentExpression();
+ init = null;
+ forIn = false;
+ } else {
+ if (match(',')) {
+ initSeq = [init];
+ while (match(',')) {
+ lex();
+ initSeq.push(isolateCoverGrammar(parseAssignmentExpression));
+ }
+ init = new WrappingNode(initStartToken).finishSequenceExpression(initSeq);
+ }
+ expect(';');
+ }
+ }
+ }
+
+ if (typeof left === 'undefined') {
+
+ if (!match(';')) {
+ test = parseExpression();
+ }
+ expect(';');
+
+ if (!match(')')) {
+ update = parseExpression();
+ }
+ }
+
+ expect(')');
+
+ oldInIteration = state.inIteration;
+ state.inIteration = true;
+
+ body = isolateCoverGrammar(parseStatement);
+
+ state.inIteration = oldInIteration;
+
+ return (typeof left === 'undefined') ?
+ node.finishForStatement(init, test, update, body) :
+ forIn ? node.finishForInStatement(left, right, body) :
+ node.finishForOfStatement(left, right, body);
+ }
+
+ // ECMA-262 13.8 The continue statement
+
+ function parseContinueStatement(node) {
+ var label = null, key;
+
+ expectKeyword('continue');
+
+ // Optimize the most common form: 'continue;'.
+ if (source.charCodeAt(startIndex) === 0x3B) {
+ lex();
+
+ if (!state.inIteration) {
+ throwError(Messages.IllegalContinue);
+ }
+
+ return node.finishContinueStatement(null);
+ }
+
+ if (hasLineTerminator) {
+ if (!state.inIteration) {
+ throwError(Messages.IllegalContinue);
+ }
+
+ return node.finishContinueStatement(null);
+ }
+
+ if (lookahead.type === Token.Identifier) {
+ label = parseVariableIdentifier();
+
+ key = '$' + label.name;
+ if (!Object.prototype.hasOwnProperty.call(state.labelSet, key)) {
+ throwError(Messages.UnknownLabel, label.name);
+ }
+ }
+
+ consumeSemicolon();
+
+ if (label === null && !state.inIteration) {
+ throwError(Messages.IllegalContinue);
+ }
+
+ return node.finishContinueStatement(label);
+ }
+
+ // ECMA-262 13.9 The break statement
+
+ function parseBreakStatement(node) {
+ var label = null, key;
+
+ expectKeyword('break');
+
+ // Catch the very common case first: immediately a semicolon (U+003B).
+ if (source.charCodeAt(lastIndex) === 0x3B) {
+ lex();
+
+ if (!(state.inIteration || state.inSwitch)) {
+ throwError(Messages.IllegalBreak);
+ }
+
+ return node.finishBreakStatement(null);
+ }
+
+ if (hasLineTerminator) {
+ if (!(state.inIteration || state.inSwitch)) {
+ throwError(Messages.IllegalBreak);
+ }
+ } else if (lookahead.type === Token.Identifier) {
+ label = parseVariableIdentifier();
+
+ key = '$' + label.name;
+ if (!Object.prototype.hasOwnProperty.call(state.labelSet, key)) {
+ throwError(Messages.UnknownLabel, label.name);
+ }
+ }
+
+ consumeSemicolon();
+
+ if (label === null && !(state.inIteration || state.inSwitch)) {
+ throwError(Messages.IllegalBreak);
+ }
+
+ return node.finishBreakStatement(label);
+ }
+
+ // ECMA-262 13.10 The return statement
+
+ function parseReturnStatement(node) {
+ var argument = null;
+
+ expectKeyword('return');
+
+ if (!state.inFunctionBody) {
+ tolerateError(Messages.IllegalReturn);
+ }
+
+ // 'return' followed by a space and an identifier is very common.
+ if (source.charCodeAt(lastIndex) === 0x20) {
+ if (isIdentifierStart(source.charCodeAt(lastIndex + 1))) {
+ argument = parseExpression();
+ consumeSemicolon();
+ return node.finishReturnStatement(argument);
+ }
+ }
+
+ if (hasLineTerminator) {
+ // HACK
+ return node.finishReturnStatement(null);
+ }
+
+ if (!match(';')) {
+ if (!match('}') && lookahead.type !== Token.EOF) {
+ argument = parseExpression();
+ }
+ }
+
+ consumeSemicolon();
+
+ return node.finishReturnStatement(argument);
+ }
+
+ // ECMA-262 13.11 The with statement
+
+ function parseWithStatement(node) {
+ var object, body;
+
+ if (strict) {
+ tolerateError(Messages.StrictModeWith);
+ }
+
+ expectKeyword('with');
+
+ expect('(');
+
+ object = parseExpression();
+
+ expect(')');
+
+ body = parseStatement();
+
+ return node.finishWithStatement(object, body);
+ }
+
+ // ECMA-262 13.12 The switch statement
+
+ function parseSwitchCase() {
+ var test, consequent = [], statement, node = new Node();
+
+ if (matchKeyword('default')) {
+ lex();
+ test = null;
+ } else {
+ expectKeyword('case');
+ test = parseExpression();
+ }
+ expect(':');
+
+ while (startIndex < length) {
+ if (match('}') || matchKeyword('default') || matchKeyword('case')) {
+ break;
+ }
+ statement = parseStatementListItem();
+ consequent.push(statement);
+ }
+
+ return node.finishSwitchCase(test, consequent);
+ }
+
+ function parseSwitchStatement(node) {
+ var discriminant, cases, clause, oldInSwitch, defaultFound;
+
+ expectKeyword('switch');
+
+ expect('(');
+
+ discriminant = parseExpression();
+
+ expect(')');
+
+ expect('{');
+
+ cases = [];
+
+ if (match('}')) {
+ lex();
+ return node.finishSwitchStatement(discriminant, cases);
+ }
+
+ oldInSwitch = state.inSwitch;
+ state.inSwitch = true;
+ defaultFound = false;
+
+ while (startIndex < length) {
+ if (match('}')) {
+ break;
+ }
+ clause = parseSwitchCase();
+ if (clause.test === null) {
+ if (defaultFound) {
+ throwError(Messages.MultipleDefaultsInSwitch);
+ }
+ defaultFound = true;
+ }
+ cases.push(clause);
+ }
+
+ state.inSwitch = oldInSwitch;
+
+ expect('}');
+
+ return node.finishSwitchStatement(discriminant, cases);
+ }
+
+ // ECMA-262 13.14 The throw statement
+
+ function parseThrowStatement(node) {
+ var argument;
+
+ expectKeyword('throw');
+
+ if (hasLineTerminator) {
+ throwError(Messages.NewlineAfterThrow);
+ }
+
+ argument = parseExpression();
+
+ consumeSemicolon();
+
+ return node.finishThrowStatement(argument);
+ }
+
+ // ECMA-262 13.15 The try statement
+
+ function parseCatchClause() {
+ var param, params = [], paramMap = {}, key, i, body, node = new Node();
+
+ expectKeyword('catch');
+
+ expect('(');
+ if (match(')')) {
+ throwUnexpectedToken(lookahead);
+ }
+
+ param = parsePattern(params);
+ for (i = 0; i < params.length; i++) {
+ key = '$' + params[i].value;
+ if (Object.prototype.hasOwnProperty.call(paramMap, key)) {
+ tolerateError(Messages.DuplicateBinding, params[i].value);
+ }
+ paramMap[key] = true;
+ }
+
+ // ECMA-262 12.14.1
+ if (strict && isRestrictedWord(param.name)) {
+ tolerateError(Messages.StrictCatchVariable);
+ }
+
+ expect(')');
+ body = parseBlock();
+ return node.finishCatchClause(param, body);
+ }
+
+ function parseTryStatement(node) {
+ var block, handler = null, finalizer = null;
+
+ expectKeyword('try');
+
+ block = parseBlock();
+
+ if (matchKeyword('catch')) {
+ handler = parseCatchClause();
+ }
+
+ if (matchKeyword('finally')) {
+ lex();
+ finalizer = parseBlock();
+ }
+
+ if (!handler && !finalizer) {
+ throwError(Messages.NoCatchOrFinally);
+ }
+
+ return node.finishTryStatement(block, handler, finalizer);
+ }
+
+ // ECMA-262 13.16 The debugger statement
+
+ function parseDebuggerStatement(node) {
+ expectKeyword('debugger');
+
+ consumeSemicolon();
+
+ return node.finishDebuggerStatement();
+ }
+
+ // 13 Statements
+
+ function parseStatement() {
+ var type = lookahead.type,
+ expr,
+ labeledBody,
+ key,
+ node;
+
+ if (type === Token.EOF) {
+ throwUnexpectedToken(lookahead);
+ }
+
+ if (type === Token.Punctuator && lookahead.value === '{') {
+ return parseBlock();
+ }
+ isAssignmentTarget = isBindingElement = true;
+ node = new Node();
+
+ if (type === Token.Punctuator) {
+ switch (lookahead.value) {
+ case ';':
+ return parseEmptyStatement(node);
+ case '(':
+ return parseExpressionStatement(node);
+ default:
+ break;
+ }
+ } else if (type === Token.Keyword) {
+ switch (lookahead.value) {
+ case 'break':
+ return parseBreakStatement(node);
+ case 'continue':
+ return parseContinueStatement(node);
+ case 'debugger':
+ return parseDebuggerStatement(node);
+ case 'do':
+ return parseDoWhileStatement(node);
+ case 'for':
+ return parseForStatement(node);
+ case 'function':
+ return parseFunctionDeclaration(node);
+ case 'if':
+ return parseIfStatement(node);
+ case 'return':
+ return parseReturnStatement(node);
+ case 'switch':
+ return parseSwitchStatement(node);
+ case 'throw':
+ return parseThrowStatement(node);
+ case 'try':
+ return parseTryStatement(node);
+ case 'var':
+ return parseVariableStatement(node);
+ case 'while':
+ return parseWhileStatement(node);
+ case 'with':
+ return parseWithStatement(node);
+ default:
+ break;
+ }
+ }
+
+ expr = parseExpression();
+
+ // ECMA-262 12.12 Labelled Statements
+ if ((expr.type === Syntax.Identifier) && match(':')) {
+ lex();
+
+ key = '$' + expr.name;
+ if (Object.prototype.hasOwnProperty.call(state.labelSet, key)) {
+ throwError(Messages.Redeclaration, 'Label', expr.name);
+ }
+
+ state.labelSet[key] = true;
+ labeledBody = parseStatement();
+ delete state.labelSet[key];
+ return node.finishLabeledStatement(expr, labeledBody);
+ }
+
+ consumeSemicolon();
+
+ return node.finishExpressionStatement(expr);
+ }
+
+ // ECMA-262 14.1 Function Definition
+
+ function parseFunctionSourceElements() {
+ var statement, body = [], token, directive, firstRestricted,
+ oldLabelSet, oldInIteration, oldInSwitch, oldInFunctionBody, oldParenthesisCount,
+ node = new Node();
+
+ expect('{');
+
+ while (startIndex < length) {
+ if (lookahead.type !== Token.StringLiteral) {
+ break;
+ }
+ token = lookahead;
+
+ statement = parseStatementListItem();
+ body.push(statement);
+ if (statement.expression.type !== Syntax.Literal) {
+ // this is not directive
+ break;
+ }
+ directive = source.slice(token.start + 1, token.end - 1);
+ if (directive === 'use strict') {
+ strict = true;
+ if (firstRestricted) {
+ tolerateUnexpectedToken(firstRestricted, Messages.StrictOctalLiteral);
+ }
+ } else {
+ if (!firstRestricted && token.octal) {
+ firstRestricted = token;
+ }
+ }
+ }
+
+ oldLabelSet = state.labelSet;
+ oldInIteration = state.inIteration;
+ oldInSwitch = state.inSwitch;
+ oldInFunctionBody = state.inFunctionBody;
+ oldParenthesisCount = state.parenthesizedCount;
+
+ state.labelSet = {};
+ state.inIteration = false;
+ state.inSwitch = false;
+ state.inFunctionBody = true;
+ state.parenthesizedCount = 0;
+
+ while (startIndex < length) {
+ if (match('}')) {
+ break;
+ }
+ body.push(parseStatementListItem());
+ }
+
+ expect('}');
+
+ state.labelSet = oldLabelSet;
+ state.inIteration = oldInIteration;
+ state.inSwitch = oldInSwitch;
+ state.inFunctionBody = oldInFunctionBody;
+ state.parenthesizedCount = oldParenthesisCount;
+
+ return node.finishBlockStatement(body);
+ }
+
+ function validateParam(options, param, name) {
+ var key = '$' + name;
+ if (strict) {
+ if (isRestrictedWord(name)) {
+ options.stricted = param;
+ options.message = Messages.StrictParamName;
+ }
+ if (Object.prototype.hasOwnProperty.call(options.paramSet, key)) {
+ options.stricted = param;
+ options.message = Messages.StrictParamDupe;
+ }
+ } else if (!options.firstRestricted) {
+ if (isRestrictedWord(name)) {
+ options.firstRestricted = param;
+ options.message = Messages.StrictParamName;
+ } else if (isStrictModeReservedWord(name)) {
+ options.firstRestricted = param;
+ options.message = Messages.StrictReservedWord;
+ } else if (Object.prototype.hasOwnProperty.call(options.paramSet, key)) {
+ options.stricted = param;
+ options.message = Messages.StrictParamDupe;
+ }
+ }
+ options.paramSet[key] = true;
+ }
+
+ function parseParam(options) {
+ var token, param, params = [], i, def;
+
+ token = lookahead;
+ if (token.value === '...') {
+ param = parseRestElement(params);
+ validateParam(options, param.argument, param.argument.name);
+ options.params.push(param);
+ options.defaults.push(null);
+ return false;
+ }
+
+ param = parsePatternWithDefault(params);
+ for (i = 0; i < params.length; i++) {
+ validateParam(options, params[i], params[i].value);
+ }
+
+ if (param.type === Syntax.AssignmentPattern) {
+ def = param.right;
+ param = param.left;
+ ++options.defaultCount;
+ }
+
+ options.params.push(param);
+ options.defaults.push(def);
+
+ return !match(')');
+ }
+
+ function parseParams(firstRestricted) {
+ var options;
+
+ options = {
+ params: [],
+ defaultCount: 0,
+ defaults: [],
+ firstRestricted: firstRestricted
+ };
+
+ expect('(');
+
+ if (!match(')')) {
+ options.paramSet = {};
+ while (startIndex < length) {
+ if (!parseParam(options)) {
+ break;
+ }
+ expect(',');
+ }
+ }
+
+ expect(')');
+
+ if (options.defaultCount === 0) {
+ options.defaults = [];
+ }
+
+ return {
+ params: options.params,
+ defaults: options.defaults,
+ stricted: options.stricted,
+ firstRestricted: options.firstRestricted,
+ message: options.message
+ };
+ }
+
+ function parseFunctionDeclaration(node, identifierIsOptional) {
+ var id = null, params = [], defaults = [], body, token, stricted, tmp, firstRestricted, message, previousStrict,
+ isGenerator, previousAllowYield;
+
+ previousAllowYield = state.allowYield;
+
+ expectKeyword('function');
+
+ isGenerator = match('*');
+ if (isGenerator) {
+ lex();
+ }
+
+ if (!identifierIsOptional || !match('(')) {
+ token = lookahead;
+ id = parseVariableIdentifier();
+ if (strict) {
+ if (isRestrictedWord(token.value)) {
+ tolerateUnexpectedToken(token, Messages.StrictFunctionName);
+ }
+ } else {
+ if (isRestrictedWord(token.value)) {
+ firstRestricted = token;
+ message = Messages.StrictFunctionName;
+ } else if (isStrictModeReservedWord(token.value)) {
+ firstRestricted = token;
+ message = Messages.StrictReservedWord;
+ }
+ }
+ }
+
+ state.allowYield = !isGenerator;
+ tmp = parseParams(firstRestricted);
+ params = tmp.params;
+ defaults = tmp.defaults;
+ stricted = tmp.stricted;
+ firstRestricted = tmp.firstRestricted;
+ if (tmp.message) {
+ message = tmp.message;
+ }
+
+
+ previousStrict = strict;
+ body = parseFunctionSourceElements();
+ if (strict && firstRestricted) {
+ throwUnexpectedToken(firstRestricted, message);
+ }
+ if (strict && stricted) {
+ tolerateUnexpectedToken(stricted, message);
+ }
+
+ strict = previousStrict;
+ state.allowYield = previousAllowYield;
+
+ return node.finishFunctionDeclaration(id, params, defaults, body, isGenerator);
+ }
+
+ function parseFunctionExpression() {
+ var token, id = null, stricted, firstRestricted, message, tmp,
+ params = [], defaults = [], body, previousStrict, node = new Node(),
+ isGenerator, previousAllowYield;
+
+ previousAllowYield = state.allowYield;
+
+ expectKeyword('function');
+
+ isGenerator = match('*');
+ if (isGenerator) {
+ lex();
+ }
+
+ state.allowYield = !isGenerator;
+ if (!match('(')) {
+ token = lookahead;
+ id = (!strict && !isGenerator && matchKeyword('yield')) ? parseNonComputedProperty() : parseVariableIdentifier();
+ if (strict) {
+ if (isRestrictedWord(token.value)) {
+ tolerateUnexpectedToken(token, Messages.StrictFunctionName);
+ }
+ } else {
+ if (isRestrictedWord(token.value)) {
+ firstRestricted = token;
+ message = Messages.StrictFunctionName;
+ } else if (isStrictModeReservedWord(token.value)) {
+ firstRestricted = token;
+ message = Messages.StrictReservedWord;
+ }
+ }
+ }
+
+ tmp = parseParams(firstRestricted);
+ params = tmp.params;
+ defaults = tmp.defaults;
+ stricted = tmp.stricted;
+ firstRestricted = tmp.firstRestricted;
+ if (tmp.message) {
+ message = tmp.message;
+ }
+
+ previousStrict = strict;
+ body = parseFunctionSourceElements();
+ if (strict && firstRestricted) {
+ throwUnexpectedToken(firstRestricted, message);
+ }
+ if (strict && stricted) {
+ tolerateUnexpectedToken(stricted, message);
+ }
+ strict = previousStrict;
+ state.allowYield = previousAllowYield;
+
+ return node.finishFunctionExpression(id, params, defaults, body, isGenerator);
+ }
+
+ // ECMA-262 14.5 Class Definitions
+
+ function parseClassBody() {
+ var classBody, token, isStatic, hasConstructor = false, body, method, computed, key;
+
+ classBody = new Node();
+
+ expect('{');
+ body = [];
+ while (!match('}')) {
+ if (match(';')) {
+ lex();
+ } else {
+ method = new Node();
+ token = lookahead;
+ isStatic = false;
+ computed = match('[');
+ if (match('*')) {
+ lex();
+ } else {
+ key = parseObjectPropertyKey();
+ if (key.name === 'static' && (lookaheadPropertyName() || match('*'))) {
+ token = lookahead;
+ isStatic = true;
+ computed = match('[');
+ if (match('*')) {
+ lex();
+ } else {
+ key = parseObjectPropertyKey();
+ }
+ }
+ }
+ method = tryParseMethodDefinition(token, key, computed, method);
+ if (method) {
+ method['static'] = isStatic; // jscs:ignore requireDotNotation
+ if (method.kind === 'init') {
+ method.kind = 'method';
+ }
+ if (!isStatic) {
+ if (!method.computed && (method.key.name || method.key.value.toString()) === 'constructor') {
+ if (method.kind !== 'method' || !method.method || method.value.generator) {
+ throwUnexpectedToken(token, Messages.ConstructorSpecialMethod);
+ }
+ if (hasConstructor) {
+ throwUnexpectedToken(token, Messages.DuplicateConstructor);
+ } else {
+ hasConstructor = true;
+ }
+ method.kind = 'constructor';
+ }
+ } else {
+ if (!method.computed && (method.key.name || method.key.value.toString()) === 'prototype') {
+ throwUnexpectedToken(token, Messages.StaticPrototype);
+ }
+ }
+ method.type = Syntax.MethodDefinition;
+ delete method.method;
+ delete method.shorthand;
+ body.push(method);
+ } else {
+ throwUnexpectedToken(lookahead);
+ }
+ }
+ }
+ lex();
+ return classBody.finishClassBody(body);
+ }
+
+ function parseClassDeclaration(identifierIsOptional) {
+ var id = null, superClass = null, classNode = new Node(), classBody, previousStrict = strict;
+ strict = true;
+
+ expectKeyword('class');
+
+ if (!identifierIsOptional || lookahead.type === Token.Identifier) {
+ id = parseVariableIdentifier();
+ }
+
+ if (matchKeyword('extends')) {
+ lex();
+ superClass = isolateCoverGrammar(parseLeftHandSideExpressionAllowCall);
+ }
+ classBody = parseClassBody();
+ strict = previousStrict;
+
+ return classNode.finishClassDeclaration(id, superClass, classBody);
+ }
+
+ function parseClassExpression() {
+ var id = null, superClass = null, classNode = new Node(), classBody, previousStrict = strict;
+ strict = true;
+
+ expectKeyword('class');
+
+ if (lookahead.type === Token.Identifier) {
+ id = parseVariableIdentifier();
+ }
+
+ if (matchKeyword('extends')) {
+ lex();
+ superClass = isolateCoverGrammar(parseLeftHandSideExpressionAllowCall);
+ }
+ classBody = parseClassBody();
+ strict = previousStrict;
+
+ return classNode.finishClassExpression(id, superClass, classBody);
+ }
+
+ // ECMA-262 15.2 Modules
+
+ function parseModuleSpecifier() {
+ var node = new Node();
+
+ if (lookahead.type !== Token.StringLiteral) {
+ throwError(Messages.InvalidModuleSpecifier);
+ }
+ return node.finishLiteral(lex());
+ }
+
+ // ECMA-262 15.2.3 Exports
+
+ function parseExportSpecifier() {
+ var exported, local, node = new Node(), def;
+ if (matchKeyword('default')) {
+ // export {default} from 'something';
+ def = new Node();
+ lex();
+ local = def.finishIdentifier('default');
+ } else {
+ local = parseVariableIdentifier();
+ }
+ if (matchContextualKeyword('as')) {
+ lex();
+ exported = parseNonComputedProperty();
+ }
+ return node.finishExportSpecifier(local, exported);
+ }
+
+ function parseExportNamedDeclaration(node) {
+ var declaration = null,
+ isExportFromIdentifier,
+ src = null, specifiers = [];
+
+ // non-default export
+ if (lookahead.type === Token.Keyword) {
+ // covers:
+ // export var f = 1;
+ switch (lookahead.value) {
+ case 'let':
+ case 'const':
+ declaration = parseLexicalDeclaration({inFor: false});
+ return node.finishExportNamedDeclaration(declaration, specifiers, null);
+ case 'var':
+ case 'class':
+ case 'function':
+ declaration = parseStatementListItem();
+ return node.finishExportNamedDeclaration(declaration, specifiers, null);
+ }
+ }
+
+ expect('{');
+ while (!match('}')) {
+ isExportFromIdentifier = isExportFromIdentifier || matchKeyword('default');
+ specifiers.push(parseExportSpecifier());
+ if (!match('}')) {
+ expect(',');
+ if (match('}')) {
+ break;
+ }
+ }
+ }
+ expect('}');
+
+ if (matchContextualKeyword('from')) {
+ // covering:
+ // export {default} from 'foo';
+ // export {foo} from 'foo';
+ lex();
+ src = parseModuleSpecifier();
+ consumeSemicolon();
+ } else if (isExportFromIdentifier) {
+ // covering:
+ // export {default}; // missing fromClause
+ throwError(lookahead.value ?
+ Messages.UnexpectedToken : Messages.MissingFromClause, lookahead.value);
+ } else {
+ // cover
+ // export {foo};
+ consumeSemicolon();
+ }
+ return node.finishExportNamedDeclaration(declaration, specifiers, src);
+ }
+
+ function parseExportDefaultDeclaration(node) {
+ var declaration = null,
+ expression = null;
+
+ // covers:
+ // export default ...
+ expectKeyword('default');
+
+ if (matchKeyword('function')) {
+ // covers:
+ // export default function foo () {}
+ // export default function () {}
+ declaration = parseFunctionDeclaration(new Node(), true);
+ return node.finishExportDefaultDeclaration(declaration);
+ }
+ if (matchKeyword('class')) {
+ declaration = parseClassDeclaration(true);
+ return node.finishExportDefaultDeclaration(declaration);
+ }
+
+ if (matchContextualKeyword('from')) {
+ throwError(Messages.UnexpectedToken, lookahead.value);
+ }
+
+ // covers:
+ // export default {};
+ // export default [];
+ // export default (1 + 2);
+ if (match('{')) {
+ expression = parseObjectInitializer();
+ } else if (match('[')) {
+ expression = parseArrayInitializer();
+ } else {
+ expression = parseAssignmentExpression();
+ }
+ consumeSemicolon();
+ return node.finishExportDefaultDeclaration(expression);
+ }
+
+ function parseExportAllDeclaration(node) {
+ var src;
+
+ // covers:
+ // export * from 'foo';
+ expect('*');
+ if (!matchContextualKeyword('from')) {
+ throwError(lookahead.value ?
+ Messages.UnexpectedToken : Messages.MissingFromClause, lookahead.value);
+ }
+ lex();
+ src = parseModuleSpecifier();
+ consumeSemicolon();
+
+ return node.finishExportAllDeclaration(src);
+ }
+
+ function parseExportDeclaration() {
+ var node = new Node();
+ if (state.inFunctionBody) {
+ throwError(Messages.IllegalExportDeclaration);
+ }
+
+ expectKeyword('export');
+
+ if (matchKeyword('default')) {
+ return parseExportDefaultDeclaration(node);
+ }
+ if (match('*')) {
+ return parseExportAllDeclaration(node);
+ }
+ return parseExportNamedDeclaration(node);
+ }
+
+ // ECMA-262 15.2.2 Imports
+
+ function parseImportSpecifier() {
+ // import {' + func(text) + '
'; + * }); + * + * p('fred, barney, & pebbles'); + * // => 'fred, barney, & pebbles
' + */ + function wrap(value, wrapper) { + wrapper = wrapper == null ? identity : wrapper; + return partial(wrapper, value); + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates a shallow clone of `value`. + * + * **Note:** This method is loosely based on the + * [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) + * and supports cloning arrays, array buffers, booleans, date objects, maps, + * numbers, `Object` objects, regexes, sets, strings, symbols, and typed + * arrays. The own enumerable properties of `arguments` objects are cloned + * as plain objects. An empty object is returned for uncloneable values such + * as error objects, functions, DOM nodes, and WeakMaps. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to clone. + * @returns {*} Returns the cloned value. + * @example + * + * var objects = [{ 'a': 1 }, { 'b': 2 }]; + * + * var shallow = _.clone(objects); + * console.log(shallow[0] === objects[0]); + * // => true + */ + function clone(value) { + return baseClone(value); + } + + /** + * This method is like `_.clone` except that it accepts `customizer` which + * is invoked to produce the cloned value. If `customizer` returns `undefined` + * cloning is handled by the method instead. The `customizer` is invoked with + * up to four arguments; (value [, index|key, object, stack]). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to clone. + * @param {Function} [customizer] The function to customize cloning. + * @returns {*} Returns the cloned value. + * @example + * + * function customizer(value) { + * if (_.isElement(value)) { + * return value.cloneNode(false); + * } + * } + * + * var el = _.cloneWith(document.body, customizer); + * + * console.log(el === document.body); + * // => false + * console.log(el.nodeName); + * // => 'BODY' + * console.log(el.childNodes.length); + * // => 0 + */ + function cloneWith(value, customizer) { + return baseClone(value, false, customizer); + } + + /** + * This method is like `_.clone` except that it recursively clones `value`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to recursively clone. + * @returns {*} Returns the deep cloned value. + * @example + * + * var objects = [{ 'a': 1 }, { 'b': 2 }]; + * + * var deep = _.cloneDeep(objects); + * console.log(deep[0] === objects[0]); + * // => false + */ + function cloneDeep(value) { + return baseClone(value, true); + } + + /** + * This method is like `_.cloneWith` except that it recursively clones `value`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to recursively clone. + * @param {Function} [customizer] The function to customize cloning. + * @returns {*} Returns the deep cloned value. + * @example + * + * function customizer(value) { + * if (_.isElement(value)) { + * return value.cloneNode(true); + * } + * } + * + * var el = _.cloneDeepWith(document.body, customizer); + * + * console.log(el === document.body); + * // => false + * console.log(el.nodeName); + * // => 'BODY' + * console.log(el.childNodes.length); + * // => 20 + */ + function cloneDeepWith(value, customizer) { + return baseClone(value, true, customizer); + } + + /** + * Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * comparison between two values to determine if they are equivalent. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + * @example + * + * var object = { 'user': 'fred' }; + * var other = { 'user': 'fred' }; + * + * _.eq(object, object); + * // => true + * + * _.eq(object, other); + * // => false + * + * _.eq('a', 'a'); + * // => true + * + * _.eq('a', Object('a')); + * // => false + * + * _.eq(NaN, NaN); + * // => true + */ + function eq(value, other) { + return value === other || (value !== value && other !== other); + } + + /** + * Checks if `value` is greater than `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is greater than `other`, else `false`. + * @example + * + * _.gt(3, 1); + * // => true + * + * _.gt(3, 3); + * // => false + * + * _.gt(1, 3); + * // => false + */ + function gt(value, other) { + return value > other; + } + + /** + * Checks if `value` is greater than or equal to `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is greater than or equal to `other`, else `false`. + * @example + * + * _.gte(3, 1); + * // => true + * + * _.gte(3, 3); + * // => true + * + * _.gte(1, 3); + * // => false + */ + function gte(value, other) { + return value >= other; + } + + /** + * Checks if `value` is likely an `arguments` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isArguments(function() { return arguments; }()); + * // => true + * + * _.isArguments([1, 2, 3]); + * // => false + */ + function isArguments(value) { + // Safari 8.1 incorrectly makes `arguments.callee` enumerable in strict mode. + return isArrayLikeObject(value) && hasOwnProperty.call(value, 'callee') && + (!propertyIsEnumerable.call(value, 'callee') || objectToString.call(value) == argsTag); + } + + /** + * Checks if `value` is classified as an `Array` object. + * + * @static + * @memberOf _ + * @type Function + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isArray([1, 2, 3]); + * // => true + * + * _.isArray(document.body.children); + * // => false + * + * _.isArray('abc'); + * // => false + * + * _.isArray(_.noop); + * // => false + */ + var isArray = Array.isArray; + + /** + * Checks if `value` is array-like. A value is considered array-like if it's + * not a function and has a `value.length` that's an integer greater than or + * equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`. + * + * @static + * @memberOf _ + * @type Function + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is array-like, else `false`. + * @example + * + * _.isArrayLike([1, 2, 3]); + * // => true + * + * _.isArrayLike(document.body.children); + * // => true + * + * _.isArrayLike('abc'); + * // => true + * + * _.isArrayLike(_.noop); + * // => false + */ + function isArrayLike(value) { + return value != null && + !(typeof value == 'function' && isFunction(value)) && isLength(getLength(value)); + } + + /** + * This method is like `_.isArrayLike` except that it also checks if `value` + * is an object. + * + * @static + * @memberOf _ + * @type Function + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an array-like object, else `false`. + * @example + * + * _.isArrayLikeObject([1, 2, 3]); + * // => true + * + * _.isArrayLikeObject(document.body.children); + * // => true + * + * _.isArrayLikeObject('abc'); + * // => false + * + * _.isArrayLikeObject(_.noop); + * // => false + */ + function isArrayLikeObject(value) { + return isObjectLike(value) && isArrayLike(value); + } + + /** + * Checks if `value` is classified as a boolean primitive or object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isBoolean(false); + * // => true + * + * _.isBoolean(null); + * // => false + */ + function isBoolean(value) { + return value === true || value === false || + (isObjectLike(value) && objectToString.call(value) == boolTag); + } + + /** + * Checks if `value` is classified as a `Date` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isDate(new Date); + * // => true + * + * _.isDate('Mon April 23 2012'); + * // => false + */ + function isDate(value) { + return isObjectLike(value) && objectToString.call(value) == dateTag; + } + + /** + * Checks if `value` is likely a DOM element. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a DOM element, else `false`. + * @example + * + * _.isElement(document.body); + * // => true + * + * _.isElement(''); + * // => false + */ + function isElement(value) { + return !!value && value.nodeType === 1 && isObjectLike(value) && !isPlainObject(value); + } + + /** + * Checks if `value` is empty. A value is considered empty unless it's an + * `arguments` object, array, string, or jQuery-like collection with a length + * greater than `0` or an object with own enumerable properties. + * + * @static + * @memberOf _ + * @category Lang + * @param {Array|Object|string} value The value to inspect. + * @returns {boolean} Returns `true` if `value` is empty, else `false`. + * @example + * + * _.isEmpty(null); + * // => true + * + * _.isEmpty(true); + * // => true + * + * _.isEmpty(1); + * // => true + * + * _.isEmpty([1, 2, 3]); + * // => false + * + * _.isEmpty({ 'a': 1 }); + * // => false + */ + function isEmpty(value) { + return (!isObjectLike(value) || isFunction(value.splice)) + ? !size(value) + : !keys(value).length; + } + + /** + * Performs a deep comparison between two values to determine if they are + * equivalent. + * + * **Note:** This method supports comparing arrays, array buffers, booleans, + * date objects, error objects, maps, numbers, `Object` objects, regexes, + * sets, strings, symbols, and typed arrays. `Object` objects are compared + * by their own, not inherited, enumerable properties. Functions and DOM + * nodes are **not** supported. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + * @example + * + * var object = { 'user': 'fred' }; + * var other = { 'user': 'fred' }; + * + * _.isEqual(object, other); + * // => true + * + * object === other; + * // => false + */ + function isEqual(value, other) { + return baseIsEqual(value, other); + } + + /** + * This method is like `_.isEqual` except that it accepts `customizer` which is + * invoked to compare values. If `customizer` returns `undefined` comparisons are + * handled by the method instead. The `customizer` is invoked with up to six arguments: + * (objValue, othValue [, index|key, object, other, stack]). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @param {Function} [customizer] The function to customize comparisons. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + * @example + * + * function isGreeting(value) { + * return /^h(?:i|ello)$/.test(value); + * } + * + * function customizer(objValue, othValue) { + * if (isGreeting(objValue) && isGreeting(othValue)) { + * return true; + * } + * } + * + * var array = ['hello', 'goodbye']; + * var other = ['hi', 'goodbye']; + * + * _.isEqualWith(array, other, customizer); + * // => true + */ + function isEqualWith(value, other, customizer) { + customizer = typeof customizer == 'function' ? customizer : undefined; + var result = customizer ? customizer(value, other) : undefined; + return result === undefined ? baseIsEqual(value, other, customizer) : !!result; + } + + /** + * Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, + * `SyntaxError`, `TypeError`, or `URIError` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an error object, else `false`. + * @example + * + * _.isError(new Error); + * // => true + * + * _.isError(Error); + * // => false + */ + function isError(value) { + return isObjectLike(value) && + typeof value.message == 'string' && objectToString.call(value) == errorTag; + } + + /** + * Checks if `value` is a finite primitive number. + * + * **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a finite number, else `false`. + * @example + * + * _.isFinite(3); + * // => true + * + * _.isFinite(Number.MAX_VALUE); + * // => true + * + * _.isFinite(3.14); + * // => true + * + * _.isFinite(Infinity); + * // => false + */ + function isFinite(value) { + return typeof value == 'number' && nativeIsFinite(value); + } + + /** + * Checks if `value` is classified as a `Function` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isFunction(_); + * // => true + * + * _.isFunction(/abc/); + * // => false + */ + function isFunction(value) { + // The use of `Object#toString` avoids issues with the `typeof` operator + // in Safari 8 which returns 'object' for typed array constructors, and + // PhantomJS 1.9 which returns 'function' for `NodeList` instances. + var tag = isObject(value) ? objectToString.call(value) : ''; + return tag == funcTag || tag == genTag; + } + + /** + * Checks if `value` is an integer. + * + * **Note:** This method is based on [`Number.isInteger`](https://mdn.io/Number/isInteger). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an integer, else `false`. + * @example + * + * _.isInteger(3); + * // => true + * + * _.isInteger(Number.MIN_VALUE); + * // => false + * + * _.isInteger(Infinity); + * // => false + * + * _.isInteger('3'); + * // => false + */ + function isInteger(value) { + return typeof value == 'number' && value == toInteger(value); + } + + /** + * Checks if `value` is a valid array-like length. + * + * **Note:** This function is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a valid length, else `false`. + * @example + * + * _.isLength(3); + * // => true + * + * _.isLength(Number.MIN_VALUE); + * // => false + * + * _.isLength(Infinity); + * // => false + * + * _.isLength('3'); + * // => false + */ + function isLength(value) { + return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER; + } + + /** + * Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`. + * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`) + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an object, else `false`. + * @example + * + * _.isObject({}); + * // => true + * + * _.isObject([1, 2, 3]); + * // => true + * + * _.isObject(_.noop); + * // => true + * + * _.isObject(null); + * // => false + */ + function isObject(value) { + // Avoid a V8 JIT bug in Chrome 19-20. + // See https://code.google.com/p/v8/issues/detail?id=2291 for more details. + var type = typeof value; + return !!value && (type == 'object' || type == 'function'); + } + + /** + * Checks if `value` is object-like. A value is object-like if it's not `null` + * and has a `typeof` result of "object". + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is object-like, else `false`. + * @example + * + * _.isObjectLike({}); + * // => true + * + * _.isObjectLike([1, 2, 3]); + * // => true + * + * _.isObjectLike(_.noop); + * // => false + * + * _.isObjectLike(null); + * // => false + */ + function isObjectLike(value) { + return !!value && typeof value == 'object'; + } + + /** + * Performs a deep comparison between `object` and `source` to determine if + * `object` contains equivalent property values. + * + * **Note:** This method supports comparing the same values as `_.isEqual`. + * + * @static + * @memberOf _ + * @category Lang + * @param {Object} object The object to inspect. + * @param {Object} source The object of property values to match. + * @returns {boolean} Returns `true` if `object` is a match, else `false`. + * @example + * + * var object = { 'user': 'fred', 'age': 40 }; + * + * _.isMatch(object, { 'age': 40 }); + * // => true + * + * _.isMatch(object, { 'age': 36 }); + * // => false + */ + function isMatch(object, source) { + return object === source || baseIsMatch(object, source, getMatchData(source)); + } + + /** + * This method is like `_.isMatch` except that it accepts `customizer` which + * is invoked to compare values. If `customizer` returns `undefined` comparisons + * are handled by the method instead. The `customizer` is invoked with five + * arguments: (objValue, srcValue, index|key, object, source). + * + * @static + * @memberOf _ + * @category Lang + * @param {Object} object The object to inspect. + * @param {Object} source The object of property values to match. + * @param {Function} [customizer] The function to customize comparisons. + * @returns {boolean} Returns `true` if `object` is a match, else `false`. + * @example + * + * function isGreeting(value) { + * return /^h(?:i|ello)$/.test(value); + * } + * + * function customizer(objValue, srcValue) { + * if (isGreeting(objValue) && isGreeting(srcValue)) { + * return true; + * } + * } + * + * var object = { 'greeting': 'hello' }; + * var source = { 'greeting': 'hi' }; + * + * _.isMatchWith(object, source, customizer); + * // => true + */ + function isMatchWith(object, source, customizer) { + customizer = typeof customizer == 'function' ? customizer : undefined; + return baseIsMatch(object, source, getMatchData(source), customizer); + } + + /** + * Checks if `value` is `NaN`. + * + * **Note:** This method is not the same as [`isNaN`](https://es5.github.io/#x15.1.2.4) + * which returns `true` for `undefined` and other non-numeric values. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`. + * @example + * + * _.isNaN(NaN); + * // => true + * + * _.isNaN(new Number(NaN)); + * // => true + * + * isNaN(undefined); + * // => true + * + * _.isNaN(undefined); + * // => false + */ + function isNaN(value) { + // An `NaN` primitive is the only value that is not equal to itself. + // Perform the `toStringTag` check first to avoid errors with some ActiveX objects in IE. + return isNumber(value) && value != +value; + } + + /** + * Checks if `value` is a native function. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a native function, else `false`. + * @example + * + * _.isNative(Array.prototype.push); + * // => true + * + * _.isNative(_); + * // => false + */ + function isNative(value) { + if (value == null) { + return false; + } + if (isFunction(value)) { + return reIsNative.test(funcToString.call(value)); + } + return isObjectLike(value) && + (isHostObject(value) ? reIsNative : reIsHostCtor).test(value); + } + + /** + * Checks if `value` is `null`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `null`, else `false`. + * @example + * + * _.isNull(null); + * // => true + * + * _.isNull(void 0); + * // => false + */ + function isNull(value) { + return value === null; + } + + /** + * Checks if `value` is `null` or `undefined`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is nullish, else `false`. + * @example + * + * _.isNil(null); + * // => true + * + * _.isNil(void 0); + * // => true + * + * _.isNil(NaN); + * // => false + */ + function isNil(value) { + return value == null; + } + + /** + * Checks if `value` is classified as a `Number` primitive or object. + * + * **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified + * as numbers, use the `_.isFinite` method. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isNumber(3); + * // => true + * + * _.isNumber(Number.MIN_VALUE); + * // => true + * + * _.isNumber(Infinity); + * // => true + * + * _.isNumber('3'); + * // => false + */ + function isNumber(value) { + return typeof value == 'number' || + (isObjectLike(value) && objectToString.call(value) == numberTag); + } + + /** + * Checks if `value` is a plain object, that is, an object created by the + * `Object` constructor or one with a `[[Prototype]]` of `null`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a plain object, else `false`. + * @example + * + * function Foo() { + * this.a = 1; + * } + * + * _.isPlainObject(new Foo); + * // => false + * + * _.isPlainObject([1, 2, 3]); + * // => false + * + * _.isPlainObject({ 'x': 0, 'y': 0 }); + * // => true + * + * _.isPlainObject(Object.create(null)); + * // => true + */ + function isPlainObject(value) { + if (!isObjectLike(value) || objectToString.call(value) != objectTag || isHostObject(value)) { + return false; + } + var proto = objectProto; + if (typeof value.constructor == 'function') { + proto = getPrototypeOf(value); + } + if (proto === null) { + return true; + } + var Ctor = proto.constructor; + return (typeof Ctor == 'function' && + Ctor instanceof Ctor && funcToString.call(Ctor) == objectCtorString); + } + + /** + * Checks if `value` is classified as a `RegExp` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isRegExp(/abc/); + * // => true + * + * _.isRegExp('/abc/'); + * // => false + */ + function isRegExp(value) { + return isObject(value) && objectToString.call(value) == regexpTag; + } + + /** + * Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 + * double precision number which isn't the result of a rounded unsafe integer. + * + * **Note:** This method is based on [`Number.isSafeInteger`](https://mdn.io/Number/isSafeInteger). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a safe integer, else `false`. + * @example + * + * _.isSafeInteger(3); + * // => true + * + * _.isSafeInteger(Number.MIN_VALUE); + * // => false + * + * _.isSafeInteger(Infinity); + * // => false + * + * _.isSafeInteger('3'); + * // => false + */ + function isSafeInteger(value) { + return isInteger(value) && value >= -MAX_SAFE_INTEGER && value <= MAX_SAFE_INTEGER; + } + + /** + * Checks if `value` is classified as a `String` primitive or object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isString('abc'); + * // => true + * + * _.isString(1); + * // => false + */ + function isString(value) { + return typeof value == 'string' || + (!isArray(value) && isObjectLike(value) && objectToString.call(value) == stringTag); + } + + /** + * Checks if `value` is classified as a `Symbol` primitive or object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isSymbol(Symbol.iterator); + * // => true + * + * _.isSymbol('abc'); + * // => false + */ + function isSymbol(value) { + return typeof value == 'symbol' || + (isObjectLike(value) && objectToString.call(value) == symbolTag); + } + + /** + * Checks if `value` is classified as a typed array. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isTypedArray(new Uint8Array); + * // => true + * + * _.isTypedArray([]); + * // => false + */ + function isTypedArray(value) { + return isObjectLike(value) && isLength(value.length) && !!typedArrayTags[objectToString.call(value)]; + } + + /** + * Checks if `value` is `undefined`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `undefined`, else `false`. + * @example + * + * _.isUndefined(void 0); + * // => true + * + * _.isUndefined(null); + * // => false + */ + function isUndefined(value) { + return value === undefined; + } + + /** + * Checks if `value` is less than `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is less than `other`, else `false`. + * @example + * + * _.lt(1, 3); + * // => true + * + * _.lt(3, 3); + * // => false + * + * _.lt(3, 1); + * // => false + */ + function lt(value, other) { + return value < other; + } + + /** + * Checks if `value` is less than or equal to `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is less than or equal to `other`, else `false`. + * @example + * + * _.lte(1, 3); + * // => true + * + * _.lte(3, 3); + * // => true + * + * _.lte(3, 1); + * // => false + */ + function lte(value, other) { + return value <= other; + } + + /** + * Converts `value` to an array. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to convert. + * @returns {Array} Returns the converted array. + * @example + * + * _.toArray({ 'a': 1, 'b': 2 }); + * // => [1, 2] + * + * _.toArray('abc'); + * // => ['a', 'b', 'c'] + * + * _.toArray(1); + * // => [] + * + * _.toArray(null); + * // => [] + */ + function toArray(value) { + if (!value) { + return []; + } + if (isArrayLike(value)) { + return isString(value) ? stringToArray(value) : copyArray(value); + } + if (iteratorSymbol && value[iteratorSymbol]) { + return iteratorToArray(value[iteratorSymbol]()); + } + var tag = getTag(value), + func = tag == mapTag ? mapToArray : (tag == setTag ? setToArray : values); + + return func(value); + } + + /** + * Converts `value` to an integer. + * + * **Note:** This function is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/6.0/#sec-tointeger). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to convert. + * @returns {number} Returns the converted integer. + * @example + * + * _.toInteger(3); + * // => 3 + * + * _.toInteger(Number.MIN_VALUE); + * // => 0 + * + * _.toInteger(Infinity); + * // => 1.7976931348623157e+308 + * + * _.toInteger('3'); + * // => 3 + */ + function toInteger(value) { + if (!value) { + return value === 0 ? value : 0; + } + value = toNumber(value); + if (value === INFINITY || value === -INFINITY) { + var sign = (value < 0 ? -1 : 1); + return sign * MAX_INTEGER; + } + var remainder = value % 1; + return value === value ? (remainder ? value - remainder : value) : 0; + } + + /** + * Converts `value` to an integer suitable for use as the length of an + * array-like object. + * + * **Note:** This method is based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to convert. + * @returns {number} Returns the converted integer. + * @example + * + * _.toLength(3); + * // => 3 + * + * _.toLength(Number.MIN_VALUE); + * // => 0 + * + * _.toLength(Infinity); + * // => 4294967295 + * + * _.toLength('3'); + * // => 3 + */ + function toLength(value) { + return value ? baseClamp(toInteger(value), 0, MAX_ARRAY_LENGTH) : 0; + } + + /** + * Converts `value` to a number. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to process. + * @returns {number} Returns the number. + * @example + * + * _.toNumber(3); + * // => 3 + * + * _.toNumber(Number.MIN_VALUE); + * // => 5e-324 + * + * _.toNumber(Infinity); + * // => Infinity + * + * _.toNumber('3'); + * // => 3 + */ + function toNumber(value) { + if (isObject(value)) { + var other = isFunction(value.valueOf) ? value.valueOf() : value; + value = isObject(other) ? (other + '') : other; + } + if (typeof value != 'string') { + return value === 0 ? value : +value; + } + value = value.replace(reTrim, ''); + var isBinary = reIsBinary.test(value); + return (isBinary || reIsOctal.test(value)) + ? freeParseInt(value.slice(2), isBinary ? 2 : 8) + : (reIsBadHex.test(value) ? NAN : +value); + } + + /** + * Converts `value` to a plain object flattening inherited enumerable + * properties of `value` to own properties of the plain object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to convert. + * @returns {Object} Returns the converted plain object. + * @example + * + * function Foo() { + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.assign({ 'a': 1 }, new Foo); + * // => { 'a': 1, 'b': 2 } + * + * _.assign({ 'a': 1 }, _.toPlainObject(new Foo)); + * // => { 'a': 1, 'b': 2, 'c': 3 } + */ + function toPlainObject(value) { + return copyObject(value, keysIn(value)); + } + + /** + * Converts `value` to a safe integer. A safe integer can be compared and + * represented correctly. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to convert. + * @returns {number} Returns the converted integer. + * @example + * + * _.toSafeInteger(3); + * // => 3 + * + * _.toSafeInteger(Number.MIN_VALUE); + * // => 0 + * + * _.toSafeInteger(Infinity); + * // => 9007199254740991 + * + * _.toSafeInteger('3'); + * // => 3 + */ + function toSafeInteger(value) { + return baseClamp(toInteger(value), -MAX_SAFE_INTEGER, MAX_SAFE_INTEGER); + } + + /** + * Converts `value` to a string if it's not one. An empty string is returned + * for `null` and `undefined` values. The sign of `-0` is preserved. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to process. + * @returns {string} Returns the string. + * @example + * + * _.toString(null); + * // => '' + * + * _.toString(-0); + * // => '-0' + * + * _.toString([1, 2, 3]); + * // => '1,2,3' + */ + function toString(value) { + // Exit early for strings to avoid a performance hit in some environments. + if (typeof value == 'string') { + return value; + } + if (value == null) { + return ''; + } + if (isSymbol(value)) { + return Symbol ? symbolToString.call(value) : ''; + } + var result = (value + ''); + return (result == '0' && (1 / value) == -INFINITY) ? '-0' : result; + } + + /*------------------------------------------------------------------------*/ + + /** + * Assigns own enumerable properties of source objects to the destination + * object. Source objects are applied from left to right. Subsequent sources + * overwrite property assignments of previous sources. + * + * **Note:** This method mutates `object` and is loosely based on + * [`Object.assign`](https://mdn.io/Object/assign). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.c = 3; + * } + * + * function Bar() { + * this.e = 5; + * } + * + * Foo.prototype.d = 4; + * Bar.prototype.f = 6; + * + * _.assign({ 'a': 1 }, new Foo, new Bar); + * // => { 'a': 1, 'c': 3, 'e': 5 } + */ + var assign = createAssigner(function(object, source) { + copyObject(source, keys(source), object); + }); + + /** + * This method is like `_.assign` except that it iterates over own and + * inherited source properties. + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @alias extend + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.b = 2; + * } + * + * function Bar() { + * this.d = 4; + * } + * + * Foo.prototype.c = 3; + * Bar.prototype.e = 5; + * + * _.assignIn({ 'a': 1 }, new Foo, new Bar); + * // => { 'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5 } + */ + var assignIn = createAssigner(function(object, source) { + copyObject(source, keysIn(source), object); + }); + + /** + * This method is like `_.assignIn` except that it accepts `customizer` which + * is invoked to produce the assigned values. If `customizer` returns `undefined` + * assignment is handled by the method instead. The `customizer` is invoked + * with five arguments: (objValue, srcValue, key, object, source). + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @alias extendWith + * @category Object + * @param {Object} object The destination object. + * @param {...Object} sources The source objects. + * @param {Function} [customizer] The function to customize assigned values. + * @returns {Object} Returns `object`. + * @example + * + * function customizer(objValue, srcValue) { + * return _.isUndefined(objValue) ? srcValue : objValue; + * } + * + * var defaults = _.partialRight(_.assignInWith, customizer); + * + * defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 }); + * // => { 'a': 1, 'b': 2 } + */ + var assignInWith = createAssigner(function(object, source, srcIndex, customizer) { + copyObjectWith(source, keysIn(source), object, customizer); + }); + + /** + * This method is like `_.assign` except that it accepts `customizer` which + * is invoked to produce the assigned values. If `customizer` returns `undefined` + * assignment is handled by the method instead. The `customizer` is invoked + * with five arguments: (objValue, srcValue, key, object, source). + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} sources The source objects. + * @param {Function} [customizer] The function to customize assigned values. + * @returns {Object} Returns `object`. + * @example + * + * function customizer(objValue, srcValue) { + * return _.isUndefined(objValue) ? srcValue : objValue; + * } + * + * var defaults = _.partialRight(_.assignWith, customizer); + * + * defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 }); + * // => { 'a': 1, 'b': 2 } + */ + var assignWith = createAssigner(function(object, source, srcIndex, customizer) { + copyObjectWith(source, keys(source), object, customizer); + }); + + /** + * Creates an array of values corresponding to `paths` of `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {...(string|string[])} [paths] The property paths of elements to pick, + * specified individually or in arrays. + * @returns {Array} Returns the new array of picked elements. + * @example + * + * var object = { 'a': [{ 'b': { 'c': 3 } }, 4] }; + * + * _.at(object, ['a[0].b.c', 'a[1]']); + * // => [3, 4] + * + * _.at(['a', 'b', 'c'], 0, 2); + * // => ['a', 'c'] + */ + var at = rest(function(object, paths) { + return baseAt(object, baseFlatten(paths)); + }); + + /** + * Creates an object that inherits from the `prototype` object. If a `properties` + * object is provided its own enumerable properties are assigned to the created object. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} prototype The object to inherit from. + * @param {Object} [properties] The properties to assign to the object. + * @returns {Object} Returns the new object. + * @example + * + * function Shape() { + * this.x = 0; + * this.y = 0; + * } + * + * function Circle() { + * Shape.call(this); + * } + * + * Circle.prototype = _.create(Shape.prototype, { + * 'constructor': Circle + * }); + * + * var circle = new Circle; + * circle instanceof Circle; + * // => true + * + * circle instanceof Shape; + * // => true + */ + function create(prototype, properties) { + var result = baseCreate(prototype); + return properties ? baseAssign(result, properties) : result; + } + + /** + * Assigns own and inherited enumerable properties of source objects to the + * destination object for all destination properties that resolve to `undefined`. + * Source objects are applied from left to right. Once a property is set, + * additional values of the same property are ignored. + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * _.defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); + * // => { 'user': 'barney', 'age': 36 } + */ + var defaults = rest(function(args) { + args.push(undefined, assignInDefaults); + return apply(assignInWith, undefined, args); + }); + + /** + * This method is like `_.defaults` except that it recursively assigns + * default properties. + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * _.defaultsDeep({ 'user': { 'name': 'barney' } }, { 'user': { 'name': 'fred', 'age': 36 } }); + * // => { 'user': { 'name': 'barney', 'age': 36 } } + * + */ + var defaultsDeep = rest(function(args) { + args.push(undefined, mergeDefaults); + return apply(mergeWith, undefined, args); + }); + + /** + * This method is like `_.find` except that it returns the key of the first + * element `predicate` returns truthy for instead of the element itself. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked per iteration. + * @returns {string|undefined} Returns the key of the matched element, else `undefined`. + * @example + * + * var users = { + * 'barney': { 'age': 36, 'active': true }, + * 'fred': { 'age': 40, 'active': false }, + * 'pebbles': { 'age': 1, 'active': true } + * }; + * + * _.findKey(users, function(o) { return o.age < 40; }); + * // => 'barney' (iteration order is not guaranteed) + * + * // using the `_.matches` iteratee shorthand + * _.findKey(users, { 'age': 1, 'active': true }); + * // => 'pebbles' + * + * // using the `_.matchesProperty` iteratee shorthand + * _.findKey(users, ['active', false]); + * // => 'fred' + * + * // using the `_.property` iteratee shorthand + * _.findKey(users, 'active'); + * // => 'barney' + */ + function findKey(object, predicate) { + return baseFind(object, getIteratee(predicate, 3), baseForOwn, true); + } + + /** + * This method is like `_.findKey` except that it iterates over elements of + * a collection in the opposite order. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked per iteration. + * @returns {string|undefined} Returns the key of the matched element, else `undefined`. + * @example + * + * var users = { + * 'barney': { 'age': 36, 'active': true }, + * 'fred': { 'age': 40, 'active': false }, + * 'pebbles': { 'age': 1, 'active': true } + * }; + * + * _.findLastKey(users, function(o) { return o.age < 40; }); + * // => returns 'pebbles' assuming `_.findKey` returns 'barney' + * + * // using the `_.matches` iteratee shorthand + * _.findLastKey(users, { 'age': 36, 'active': true }); + * // => 'barney' + * + * // using the `_.matchesProperty` iteratee shorthand + * _.findLastKey(users, ['active', false]); + * // => 'fred' + * + * // using the `_.property` iteratee shorthand + * _.findLastKey(users, 'active'); + * // => 'pebbles' + */ + function findLastKey(object, predicate) { + return baseFind(object, getIteratee(predicate, 3), baseForOwnRight, true); + } + + /** + * Iterates over own and inherited enumerable properties of an object invoking + * `iteratee` for each property. The iteratee is invoked with three arguments: + * (value, key, object). Iteratee functions may exit iteration early by explicitly + * returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forIn(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'a', 'b', then 'c' (iteration order is not guaranteed) + */ + function forIn(object, iteratee) { + return object == null ? object : baseFor(object, toFunction(iteratee), keysIn); + } + + /** + * This method is like `_.forIn` except that it iterates over properties of + * `object` in the opposite order. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forInRight(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'c', 'b', then 'a' assuming `_.forIn` logs 'a', 'b', then 'c' + */ + function forInRight(object, iteratee) { + return object == null ? object : baseForRight(object, toFunction(iteratee), keysIn); + } + + /** + * Iterates over own enumerable properties of an object invoking `iteratee` + * for each property. The iteratee is invoked with three arguments: + * (value, key, object). Iteratee functions may exit iteration early by + * explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forOwn(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'a' then 'b' (iteration order is not guaranteed) + */ + function forOwn(object, iteratee) { + return object && baseForOwn(object, toFunction(iteratee)); + } + + /** + * This method is like `_.forOwn` except that it iterates over properties of + * `object` in the opposite order. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forOwnRight(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'b' then 'a' assuming `_.forOwn` logs 'a' then 'b' + */ + function forOwnRight(object, iteratee) { + return object && baseForOwnRight(object, toFunction(iteratee)); + } + + /** + * Creates an array of function property names from own enumerable properties + * of `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to inspect. + * @returns {Array} Returns the new array of property names. + * @example + * + * function Foo() { + * this.a = _.constant('a'); + * this.b = _.constant('b'); + * } + * + * Foo.prototype.c = _.constant('c'); + * + * _.functions(new Foo); + * // => ['a', 'b'] + */ + function functions(object) { + return object == null ? [] : baseFunctions(object, keys(object)); + } + + /** + * Creates an array of function property names from own and inherited + * enumerable properties of `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to inspect. + * @returns {Array} Returns the new array of property names. + * @example + * + * function Foo() { + * this.a = _.constant('a'); + * this.b = _.constant('b'); + * } + * + * Foo.prototype.c = _.constant('c'); + * + * _.functionsIn(new Foo); + * // => ['a', 'b', 'c'] + */ + function functionsIn(object) { + return object == null ? [] : baseFunctions(object, keysIn(object)); + } + + /** + * Gets the value at `path` of `object`. If the resolved value is + * `undefined` the `defaultValue` is used in its place. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path of the property to get. + * @param {*} [defaultValue] The value returned if the resolved value is `undefined`. + * @returns {*} Returns the resolved value. + * @example + * + * var object = { 'a': [{ 'b': { 'c': 3 } }] }; + * + * _.get(object, 'a[0].b.c'); + * // => 3 + * + * _.get(object, ['a', '0', 'b', 'c']); + * // => 3 + * + * _.get(object, 'a.b.c', 'default'); + * // => 'default' + */ + function get(object, path, defaultValue) { + var result = object == null ? undefined : baseGet(object, path); + return result === undefined ? defaultValue : result; + } + + /** + * Checks if `path` is a direct property of `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path to check. + * @returns {boolean} Returns `true` if `path` exists, else `false`. + * @example + * + * var object = { 'a': { 'b': { 'c': 3 } } }; + * var other = _.create({ 'a': _.create({ 'b': _.create({ 'c': 3 }) }) }); + * + * _.has(object, 'a'); + * // => true + * + * _.has(object, 'a.b.c'); + * // => true + * + * _.has(object, ['a', 'b', 'c']); + * // => true + * + * _.has(other, 'a'); + * // => false + */ + function has(object, path) { + return hasPath(object, path, baseHas); + } + + /** + * Checks if `path` is a direct or inherited property of `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path to check. + * @returns {boolean} Returns `true` if `path` exists, else `false`. + * @example + * + * var object = _.create({ 'a': _.create({ 'b': _.create({ 'c': 3 }) }) }); + * + * _.hasIn(object, 'a'); + * // => true + * + * _.hasIn(object, 'a.b.c'); + * // => true + * + * _.hasIn(object, ['a', 'b', 'c']); + * // => true + * + * _.hasIn(object, 'b'); + * // => false + */ + function hasIn(object, path) { + return hasPath(object, path, baseHasIn); + } + + /** + * Creates an object composed of the inverted keys and values of `object`. + * If `object` contains duplicate values, subsequent values overwrite property + * assignments of previous values unless `multiVal` is `true`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to invert. + * @param {boolean} [multiVal] Allow multiple values per key. + * @param- {Object} [guard] Enables use as an iteratee for functions like `_.map`. + * @returns {Object} Returns the new inverted object. + * @example + * + * var object = { 'a': 1, 'b': 2, 'c': 1 }; + * + * _.invert(object); + * // => { '1': 'c', '2': 'b' } + * + * // with `multiVal` + * _.invert(object, true); + * // => { '1': ['a', 'c'], '2': ['b'] } + */ + function invert(object, multiVal, guard) { + return arrayReduce(keys(object), function(result, key) { + var value = object[key]; + if (multiVal && !guard) { + if (hasOwnProperty.call(result, value)) { + result[value].push(key); + } else { + result[value] = [key]; + } + } + else { + result[value] = key; + } + return result; + }, {}); + } + + /** + * Invokes the method at `path` of `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path of the method to invoke. + * @param {...*} [args] The arguments to invoke the method with. + * @returns {*} Returns the result of the invoked method. + * @example + * + * var object = { 'a': [{ 'b': { 'c': [1, 2, 3, 4] } }] }; + * + * _.invoke(object, 'a[0].b.c.slice', 1, 3); + * // => [2, 3] + */ + var invoke = rest(baseInvoke); + + /** + * Creates an array of the own enumerable property names of `object`. + * + * **Note:** Non-object values are coerced to objects. See the + * [ES spec](http://ecma-international.org/ecma-262/6.0/#sec-object.keys) + * for more details. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property names. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.keys(new Foo); + * // => ['a', 'b'] (iteration order is not guaranteed) + * + * _.keys('hi'); + * // => ['0', '1'] + */ + function keys(object) { + var isProto = isPrototype(object); + if (!(isProto || isArrayLike(object))) { + return baseKeys(object); + } + var indexes = indexKeys(object), + skipIndexes = !!indexes, + result = indexes || [], + length = result.length; + + for (var key in object) { + if (baseHas(object, key) && + !(skipIndexes && (key == 'length' || isIndex(key, length))) && + !(isProto && key == 'constructor')) { + result.push(key); + } + } + return result; + } + + /** + * Creates an array of the own and inherited enumerable property names of `object`. + * + * **Note:** Non-object values are coerced to objects. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property names. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.keysIn(new Foo); + * // => ['a', 'b', 'c'] (iteration order is not guaranteed) + */ + function keysIn(object) { + var index = -1, + isProto = isPrototype(object), + props = baseKeysIn(object), + propsLength = props.length, + indexes = indexKeys(object), + skipIndexes = !!indexes, + result = indexes || [], + length = result.length; + + while (++index < propsLength) { + var key = props[index]; + if (!(skipIndexes && (key == 'length' || isIndex(key, length))) && + !(key == 'constructor' && (isProto || !hasOwnProperty.call(object, key)))) { + result.push(key); + } + } + return result; + } + + /** + * The opposite of `_.mapValues`; this method creates an object with the + * same values as `object` and keys generated by running each own enumerable + * property of `object` through `iteratee`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked per iteration. + * @returns {Object} Returns the new mapped object. + * @example + * + * _.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) { + * return key + value; + * }); + * // => { 'a1': 1, 'b2': 2 } + */ + function mapKeys(object, iteratee) { + var result = {}; + iteratee = getIteratee(iteratee, 3); + + baseForOwn(object, function(value, key, object) { + result[iteratee(value, key, object)] = value; + }); + return result; + } + + /** + * Creates an object with the same keys as `object` and values generated by + * running each own enumerable property of `object` through `iteratee`. The + * iteratee function is invoked with three arguments: (value, key, object). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked per iteration. + * @returns {Object} Returns the new mapped object. + * @example + * + * var users = { + * 'fred': { 'user': 'fred', 'age': 40 }, + * 'pebbles': { 'user': 'pebbles', 'age': 1 } + * }; + * + * _.mapValues(users, function(o) { return o.age; }); + * // => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed) + * + * // using the `_.property` iteratee shorthand + * _.mapValues(users, 'age'); + * // => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed) + */ + function mapValues(object, iteratee) { + var result = {}; + iteratee = getIteratee(iteratee, 3); + + baseForOwn(object, function(value, key, object) { + result[key] = iteratee(value, key, object); + }); + return result; + } + + /** + * Recursively merges own and inherited enumerable properties of source + * objects into the destination object, skipping source properties that resolve + * to `undefined`. Array and plain object properties are merged recursively. + * Other objects and value types are overridden by assignment. Source objects + * are applied from left to right. Subsequent sources overwrite property + * assignments of previous sources. + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * var users = { + * 'data': [{ 'user': 'barney' }, { 'user': 'fred' }] + * }; + * + * var ages = { + * 'data': [{ 'age': 36 }, { 'age': 40 }] + * }; + * + * _.merge(users, ages); + * // => { 'data': [{ 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 }] } + */ + var merge = createAssigner(function(object, source, srcIndex) { + baseMerge(object, source, srcIndex); + }); + + /** + * This method is like `_.merge` except that it accepts `customizer` which + * is invoked to produce the merged values of the destination and source + * properties. If `customizer` returns `undefined` merging is handled by the + * method instead. The `customizer` is invoked with seven arguments: + * (objValue, srcValue, key, object, source, stack). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} sources The source objects. + * @param {Function} customizer The function to customize assigned values. + * @returns {Object} Returns `object`. + * @example + * + * function customizer(objValue, srcValue) { + * if (_.isArray(objValue)) { + * return objValue.concat(srcValue); + * } + * } + * + * var object = { + * 'fruits': ['apple'], + * 'vegetables': ['beet'] + * }; + * + * var other = { + * 'fruits': ['banana'], + * 'vegetables': ['carrot'] + * }; + * + * _.mergeWith(object, other, customizer); + * // => { 'fruits': ['apple', 'banana'], 'vegetables': ['beet', 'carrot'] } + */ + var mergeWith = createAssigner(function(object, source, srcIndex, customizer) { + baseMerge(object, source, srcIndex, customizer); + }); + + /** + * The opposite of `_.pick`; this method creates an object composed of the + * own and inherited enumerable properties of `object` that are not omitted. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The source object. + * @param {...(string|string[])} [props] The property names to omit, specified + * individually or in arrays.. + * @returns {Object} Returns the new object. + * @example + * + * var object = { 'a': 1, 'b': '2', 'c': 3 }; + * + * _.omit(object, ['a', 'c']); + * // => { 'b': '2' } + */ + var omit = rest(function(object, props) { + if (object == null) { + return {}; + } + props = arrayMap(baseFlatten(props), String); + return basePick(object, baseDifference(keysIn(object), props)); + }); + + /** + * The opposite of `_.pickBy`; this method creates an object composed of the + * own and inherited enumerable properties of `object` that `predicate` + * doesn't return truthy for. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The source object. + * @param {Function|Object|string} [predicate=_.identity] The function invoked per property. + * @returns {Object} Returns the new object. + * @example + * + * var object = { 'a': 1, 'b': '2', 'c': 3 }; + * + * _.omitBy(object, _.isNumber); + * // => { 'b': '2' } + */ + function omitBy(object, predicate) { + predicate = getIteratee(predicate, 2); + return basePickBy(object, function(value, key) { + return !predicate(value, key); + }); + } + + /** + * Creates an object composed of the picked `object` properties. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The source object. + * @param {...(string|string[])} [props] The property names to pick, specified + * individually or in arrays. + * @returns {Object} Returns the new object. + * @example + * + * var object = { 'a': 1, 'b': '2', 'c': 3 }; + * + * _.pick(object, ['a', 'c']); + * // => { 'a': 1, 'c': 3 } + */ + var pick = rest(function(object, props) { + return object == null ? {} : basePick(object, baseFlatten(props)); + }); + + /** + * Creates an object composed of the `object` properties `predicate` returns + * truthy for. The predicate is invoked with one argument: (value). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The source object. + * @param {Function|Object|string} [predicate=_.identity] The function invoked per property. + * @returns {Object} Returns the new object. + * @example + * + * var object = { 'a': 1, 'b': '2', 'c': 3 }; + * + * _.pickBy(object, _.isNumber); + * // => { 'a': 1, 'c': 3 } + */ + function pickBy(object, predicate) { + return object == null ? {} : basePickBy(object, getIteratee(predicate, 2)); + } + + /** + * This method is like `_.get` except that if the resolved value is a function + * it's invoked with the `this` binding of its parent object and its result + * is returned. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path of the property to resolve. + * @param {*} [defaultValue] The value returned if the resolved value is `undefined`. + * @returns {*} Returns the resolved value. + * @example + * + * var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] }; + * + * _.result(object, 'a[0].b.c1'); + * // => 3 + * + * _.result(object, 'a[0].b.c2'); + * // => 4 + * + * _.result(object, 'a[0].b.c3', 'default'); + * // => 'default' + * + * _.result(object, 'a[0].b.c3', _.constant('default')); + * // => 'default' + */ + function result(object, path, defaultValue) { + if (!isKey(path, object)) { + path = baseToPath(path); + var result = get(object, path); + object = parent(object, path); + } else { + result = object == null ? undefined : object[path]; + } + if (result === undefined) { + result = defaultValue; + } + return isFunction(result) ? result.call(object) : result; + } + + /** + * Sets the value at `path` of `object`. If a portion of `path` doesn't exist + * it's created. Arrays are created for missing index properties while objects + * are created for all other missing properties. Use `_.setWith` to customize + * `path` creation. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to modify. + * @param {Array|string} path The path of the property to set. + * @param {*} value The value to set. + * @returns {Object} Returns `object`. + * @example + * + * var object = { 'a': [{ 'b': { 'c': 3 } }] }; + * + * _.set(object, 'a[0].b.c', 4); + * console.log(object.a[0].b.c); + * // => 4 + * + * _.set(object, 'x[0].y.z', 5); + * console.log(object.x[0].y.z); + * // => 5 + */ + function set(object, path, value) { + return object == null ? object : baseSet(object, path, value); + } + + /** + * This method is like `_.set` except that it accepts `customizer` which is + * invoked to produce the objects of `path`. If `customizer` returns `undefined` + * path creation is handled by the method instead. The `customizer` is invoked + * with three arguments: (nsValue, key, nsObject). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to modify. + * @param {Array|string} path The path of the property to set. + * @param {*} value The value to set. + * @param {Function} [customizer] The function to customize assigned values. + * @returns {Object} Returns `object`. + * @example + * + * _.setWith({ '0': { 'length': 2 } }, '[0][1][2]', 3, Object); + * // => { '0': { '1': { '2': 3 }, 'length': 2 } } + */ + function setWith(object, path, value, customizer) { + customizer = typeof customizer == 'function' ? customizer : undefined; + return object == null ? object : baseSet(object, path, value, customizer); + } + + /** + * Creates an array of own enumerable key-value pairs for `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the new array of key-value pairs. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.toPairs(new Foo); + * // => [['a', 1], ['b', 2]] (iteration order is not guaranteed) + */ + function toPairs(object) { + return baseToPairs(object, keys(object)); + } + + /** + * Creates an array of own and inherited enumerable key-value pairs for `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the new array of key-value pairs. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.toPairsIn(new Foo); + * // => [['a', 1], ['b', 2], ['c', 1]] (iteration order is not guaranteed) + */ + function toPairsIn(object) { + return baseToPairs(object, keysIn(object)); + } + + /** + * An alternative to `_.reduce`; this method transforms `object` to a new + * `accumulator` object which is the result of running each of its own enumerable + * properties through `iteratee`, with each invocation potentially mutating + * the `accumulator` object. The iteratee is invoked with four arguments: + * (accumulator, value, key, object). Iteratee functions may exit iteration + * early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Array|Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [accumulator] The custom accumulator value. + * @returns {*} Returns the accumulated value. + * @example + * + * _.transform([2, 3, 4], function(result, n) { + * result.push(n *= n); + * return n % 2 == 0; + * }); + * // => [4, 9] + * + * _.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) { + * (result[value] || (result[value] = [])).push(key); + * }); + * // => { '1': ['a', 'c'], '2': ['b'] } + */ + function transform(object, iteratee, accumulator) { + var isArr = isArray(object) || isTypedArray(object); + iteratee = getIteratee(iteratee, 4); + + if (accumulator == null) { + if (isArr || isObject(object)) { + var Ctor = object.constructor; + if (isArr) { + accumulator = isArray(object) ? new Ctor : []; + } else { + accumulator = baseCreate(isFunction(Ctor) ? Ctor.prototype : undefined); + } + } else { + accumulator = {}; + } + } + (isArr ? arrayEach : baseForOwn)(object, function(value, index, object) { + return iteratee(accumulator, value, index, object); + }); + return accumulator; + } + + /** + * Removes the property at `path` of `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to modify. + * @param {Array|string} path The path of the property to unset. + * @returns {boolean} Returns `true` if the property is deleted, else `false`. + * @example + * + * var object = { 'a': [{ 'b': { 'c': 7 } }] }; + * _.unset(object, 'a[0].b.c'); + * // => true + * + * console.log(object); + * // => { 'a': [{ 'b': {} }] }; + * + * _.unset(object, 'a[0].b.c'); + * // => true + * + * console.log(object); + * // => { 'a': [{ 'b': {} }] }; + */ + function unset(object, path) { + return object == null ? true : baseUnset(object, path); + } + + /** + * Creates an array of the own enumerable property values of `object`. + * + * **Note:** Non-object values are coerced to objects. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property values. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.values(new Foo); + * // => [1, 2] (iteration order is not guaranteed) + * + * _.values('hi'); + * // => ['h', 'i'] + */ + function values(object) { + return object ? baseValues(object, keys(object)) : []; + } + + /** + * Creates an array of the own and inherited enumerable property values of `object`. + * + * **Note:** Non-object values are coerced to objects. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property values. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.valuesIn(new Foo); + * // => [1, 2, 3] (iteration order is not guaranteed) + */ + function valuesIn(object) { + return object == null ? baseValues(object, keysIn(object)) : []; + } + + /*------------------------------------------------------------------------*/ + + /** + * Clamps `number` within the inclusive `lower` and `upper` bounds. + * + * @static + * @memberOf _ + * @category Number + * @param {number} number The number to clamp. + * @param {number} [lower] The lower bound. + * @param {number} upper The upper bound. + * @returns {number} Returns the clamped number. + * @example + * + * _.clamp(-10, -5, 5); + * // => -5 + * + * _.clamp(10, -5, 5); + * // => 5 + */ + function clamp(number, lower, upper) { + if (upper === undefined) { + upper = lower; + lower = undefined; + } + if (upper !== undefined) { + upper = toNumber(upper); + upper = upper === upper ? upper : 0; + } + if (lower !== undefined) { + lower = toNumber(lower); + lower = lower === lower ? lower : 0; + } + return baseClamp(toNumber(number), lower, upper); + } + + /** + * Checks if `n` is between `start` and up to but not including, `end`. If + * `end` is not specified it's set to `start` with `start` then set to `0`. + * If `start` is greater than `end` the params are swapped to support + * negative ranges. + * + * @static + * @memberOf _ + * @category Number + * @param {number} number The number to check. + * @param {number} [start=0] The start of the range. + * @param {number} end The end of the range. + * @returns {boolean} Returns `true` if `number` is in the range, else `false`. + * @example + * + * _.inRange(3, 2, 4); + * // => true + * + * _.inRange(4, 8); + * // => true + * + * _.inRange(4, 2); + * // => false + * + * _.inRange(2, 2); + * // => false + * + * _.inRange(1.2, 2); + * // => true + * + * _.inRange(5.2, 4); + * // => false + * + * _.inRange(-3, -2, -6); + * // => true + */ + function inRange(number, start, end) { + start = toNumber(start) || 0; + if (end === undefined) { + end = start; + start = 0; + } else { + end = toNumber(end) || 0; + } + number = toNumber(number); + return baseInRange(number, start, end); + } + + /** + * Produces a random number between the inclusive `lower` and `upper` bounds. + * If only one argument is provided a number between `0` and the given number + * is returned. If `floating` is `true`, or either `lower` or `upper` are floats, + * a floating-point number is returned instead of an integer. + * + * **Note:** JavaScript follows the IEEE-754 standard for resolving + * floating-point values which can produce unexpected results. + * + * @static + * @memberOf _ + * @category Number + * @param {number} [lower=0] The lower bound. + * @param {number} [upper=1] The upper bound. + * @param {boolean} [floating] Specify returning a floating-point number. + * @returns {number} Returns the random number. + * @example + * + * _.random(0, 5); + * // => an integer between 0 and 5 + * + * _.random(5); + * // => also an integer between 0 and 5 + * + * _.random(5, true); + * // => a floating-point number between 0 and 5 + * + * _.random(1.2, 5.2); + * // => a floating-point number between 1.2 and 5.2 + */ + function random(lower, upper, floating) { + if (floating && typeof floating != 'boolean' && isIterateeCall(lower, upper, floating)) { + upper = floating = undefined; + } + if (floating === undefined) { + if (typeof upper == 'boolean') { + floating = upper; + upper = undefined; + } + else if (typeof lower == 'boolean') { + floating = lower; + lower = undefined; + } + } + if (lower === undefined && upper === undefined) { + lower = 0; + upper = 1; + } + else { + lower = toNumber(lower) || 0; + if (upper === undefined) { + upper = lower; + lower = 0; + } else { + upper = toNumber(upper) || 0; + } + } + if (lower > upper) { + var temp = lower; + lower = upper; + upper = temp; + } + if (floating || lower % 1 || upper % 1) { + var rand = nativeRandom(); + return nativeMin(lower + (rand * (upper - lower + freeParseFloat('1e-' + ((rand + '').length - 1)))), upper); + } + return baseRandom(lower, upper); + } + + /*------------------------------------------------------------------------*/ + + /** + * Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the camel cased string. + * @example + * + * _.camelCase('Foo Bar'); + * // => 'fooBar' + * + * _.camelCase('--foo-bar'); + * // => 'fooBar' + * + * _.camelCase('__foo_bar__'); + * // => 'fooBar' + */ + var camelCase = createCompounder(function(result, word, index) { + word = word.toLowerCase(); + return result + (index ? capitalize(word) : word); + }); + + /** + * Converts the first character of `string` to upper case and the remaining + * to lower case. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to capitalize. + * @returns {string} Returns the capitalized string. + * @example + * + * _.capitalize('FRED'); + * // => 'Fred' + */ + function capitalize(string) { + return upperFirst(toString(string).toLowerCase()); + } + + /** + * Deburrs `string` by converting [latin-1 supplementary letters](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) + * to basic latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to deburr. + * @returns {string} Returns the deburred string. + * @example + * + * _.deburr('déjà vu'); + * // => 'deja vu' + */ + function deburr(string) { + string = toString(string); + return string && string.replace(reLatin1, deburrLetter).replace(reComboMark, ''); + } + + /** + * Checks if `string` ends with the given target string. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to search. + * @param {string} [target] The string to search for. + * @param {number} [position=string.length] The position to search from. + * @returns {boolean} Returns `true` if `string` ends with `target`, else `false`. + * @example + * + * _.endsWith('abc', 'c'); + * // => true + * + * _.endsWith('abc', 'b'); + * // => false + * + * _.endsWith('abc', 'b', 2); + * // => true + */ + function endsWith(string, target, position) { + string = toString(string); + target = typeof target == 'string' ? target : (target + ''); + + var length = string.length; + position = position === undefined + ? length + : baseClamp(toInteger(position), 0, length); + + position -= target.length; + return position >= 0 && string.indexOf(target, position) == position; + } + + /** + * Converts the characters "&", "<", ">", '"', "'", and "\`" in `string` to + * their corresponding HTML entities. + * + * **Note:** No other characters are escaped. To escape additional + * characters use a third-party library like [_he_](https://mths.be/he). + * + * Though the ">" character is escaped for symmetry, characters like + * ">" and "/" don't need escaping in HTML and have no special meaning + * unless they're part of a tag or unquoted attribute value. + * See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) + * (under "semi-related fun fact") for more details. + * + * Backticks are escaped because in IE < 9, they can break out of + * attribute values or HTML comments. See [#59](https://html5sec.org/#59), + * [#102](https://html5sec.org/#102), [#108](https://html5sec.org/#108), and + * [#133](https://html5sec.org/#133) of the [HTML5 Security Cheatsheet](https://html5sec.org/) + * for more details. + * + * When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) + * to reduce XSS vectors. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escape('fred, barney, & pebbles'); + * // => 'fred, barney, & pebbles' + */ + function escape(string) { + string = toString(string); + return (string && reHasUnescapedHtml.test(string)) + ? string.replace(reUnescapedHtml, escapeHtmlChar) + : string; + } + + /** + * Escapes the `RegExp` special characters "^", "$", "\", ".", "*", "+", + * "?", "(", ")", "[", "]", "{", "}", and "|" in `string`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escapeRegExp('[lodash](https://lodash.com/)'); + * // => '\[lodash\]\(https://lodash\.com/\)' + */ + function escapeRegExp(string) { + string = toString(string); + return (string && reHasRegExpChar.test(string)) + ? string.replace(reRegExpChar, '\\$&') + : string; + } + + /** + * Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the kebab cased string. + * @example + * + * _.kebabCase('Foo Bar'); + * // => 'foo-bar' + * + * _.kebabCase('fooBar'); + * // => 'foo-bar' + * + * _.kebabCase('__foo_bar__'); + * // => 'foo-bar' + */ + var kebabCase = createCompounder(function(result, word, index) { + return result + (index ? '-' : '') + word.toLowerCase(); + }); + + /** + * Converts `string`, as space separated words, to lower case. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the lower cased string. + * @example + * + * _.lowerCase('--Foo-Bar'); + * // => 'foo bar' + * + * _.lowerCase('fooBar'); + * // => 'foo bar' + * + * _.lowerCase('__FOO_BAR__'); + * // => 'foo bar' + */ + var lowerCase = createCompounder(function(result, word, index) { + return result + (index ? ' ' : '') + word.toLowerCase(); + }); + + /** + * Converts the first character of `string` to lower case. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the converted string. + * @example + * + * _.lowerFirst('Fred'); + * // => 'fred' + * + * _.lowerFirst('FRED'); + * // => 'fRED' + */ + var lowerFirst = createCaseFirst('toLowerCase'); + + /** + * Converts the first character of `string` to upper case. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the converted string. + * @example + * + * _.upperFirst('fred'); + * // => 'Fred' + * + * _.upperFirst('FRED'); + * // => 'FRED' + */ + var upperFirst = createCaseFirst('toUpperCase'); + + /** + * Pads `string` on the left and right sides if it's shorter than `length`. + * Padding characters are truncated if they can't be evenly divided by `length`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. + * @example + * + * _.pad('abc', 8); + * // => ' abc ' + * + * _.pad('abc', 8, '_-'); + * // => '_-abc_-_' + * + * _.pad('abc', 3); + * // => 'abc' + */ + function pad(string, length, chars) { + string = toString(string); + length = toInteger(length); + + var strLength = stringSize(string); + if (!length || strLength >= length) { + return string; + } + var mid = (length - strLength) / 2, + leftLength = nativeFloor(mid), + rightLength = nativeCeil(mid); + + return createPadding('', leftLength, chars) + string + createPadding('', rightLength, chars); + } + + /** + * Pads `string` on the right side if it's shorter than `length`. Padding + * characters are truncated if they exceed `length`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. + * @example + * + * _.padEnd('abc', 6); + * // => 'abc ' + * + * _.padEnd('abc', 6, '_-'); + * // => 'abc_-_' + * + * _.padEnd('abc', 3); + * // => 'abc' + */ + function padEnd(string, length, chars) { + string = toString(string); + return string + createPadding(string, length, chars); + } + + /** + * Pads `string` on the left side if it's shorter than `length`. Padding + * characters are truncated if they exceed `length`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. + * @example + * + * _.padStart('abc', 6); + * // => ' abc' + * + * _.padStart('abc', 6, '_-'); + * // => '_-_abc' + * + * _.padStart('abc', 3); + * // => 'abc' + */ + function padStart(string, length, chars) { + string = toString(string); + return createPadding(string, length, chars) + string; + } + + /** + * Converts `string` to an integer of the specified radix. If `radix` is + * `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, + * in which case a `radix` of `16` is used. + * + * **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#x15.1.2.2) + * of `parseInt`. + * + * @static + * @memberOf _ + * @category String + * @param {string} string The string to convert. + * @param {number} [radix] The radix to interpret `value` by. + * @param- {Object} [guard] Enables use as an iteratee for functions like `_.map`. + * @returns {number} Returns the converted integer. + * @example + * + * _.parseInt('08'); + * // => 8 + * + * _.map(['6', '08', '10'], _.parseInt); + * // => [6, 8, 10] + */ + function parseInt(string, radix, guard) { + // Chrome fails to trim leading{{ "%+010d"|sprintf:-123 }}
+ {{ "%+010d"|vsprintf:[-123] }}
+ {{ "%+010d"|fmt:-123 }}
+ {{ "%+010d"|vfmt:[-123] }}
+ {{ "I've got %2$d apples and %1$d oranges."|fmt:4:2 }}
+ {{ "I've got %(apples)d apples and %(oranges)d oranges."|fmt:{apples: 2, oranges: 4} }}
+
+
+
+
diff --git a/tools/doc/node_modules/sprintf-js/dist/angular-sprintf.min.js b/tools/doc/node_modules/sprintf-js/dist/angular-sprintf.min.js
new file mode 100644
index 00000000000000..dbaf744d83c214
--- /dev/null
+++ b/tools/doc/node_modules/sprintf-js/dist/angular-sprintf.min.js
@@ -0,0 +1,4 @@
+/*! sprintf-js | Alexandru Marasteanu