diff options
Diffstat (limited to 'vendor/github.com/robertkrimen/otto/parser')
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/Makefile | 4 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/README.markdown | 190 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/dbg.go | 9 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/error.go | 175 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/expression.go | 1005 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/lexer.go | 866 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/parser.go | 344 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/regexp.go | 358 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/scope.go | 44 | ||||
-rw-r--r-- | vendor/github.com/robertkrimen/otto/parser/statement.go | 938 |
10 files changed, 3933 insertions, 0 deletions
diff --git a/vendor/github.com/robertkrimen/otto/parser/Makefile b/vendor/github.com/robertkrimen/otto/parser/Makefile new file mode 100644 index 000000000..766fd4d0b --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/Makefile @@ -0,0 +1,4 @@ +.PHONY: test + +test: + go test diff --git a/vendor/github.com/robertkrimen/otto/parser/README.markdown b/vendor/github.com/robertkrimen/otto/parser/README.markdown new file mode 100644 index 000000000..c3cae5b60 --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/README.markdown @@ -0,0 +1,190 @@ +# parser +-- + import "github.com/robertkrimen/otto/parser" + +Package parser implements a parser for JavaScript. + + import ( + "github.com/robertkrimen/otto/parser" + ) + +Parse and return an AST + + filename := "" // A filename is optional + src := ` + // Sample xyzzy example + (function(){ + if (3.14159 > 0) { + console.log("Hello, World."); + return; + } + + var xyzzy = NaN; + console.log("Nothing happens."); + return xyzzy; + })(); + ` + + // Parse some JavaScript, yielding a *ast.Program and/or an ErrorList + program, err := parser.ParseFile(nil, filename, src, 0) + + +### Warning + +The parser and AST interfaces are still works-in-progress (particularly where +node types are concerned) and may change in the future. + +## Usage + +#### func ParseFile + +```go +func ParseFile(fileSet *file.FileSet, filename string, src interface{}, mode Mode) (*ast.Program, error) +``` +ParseFile parses the source code of a single JavaScript/ECMAScript source file +and returns the corresponding ast.Program node. + +If fileSet == nil, ParseFile parses source without a FileSet. If fileSet != nil, +ParseFile first adds filename and src to fileSet. + +The filename argument is optional and is used for labelling errors, etc. + +src may be a string, a byte slice, a bytes.Buffer, or an io.Reader, but it MUST +always be in UTF-8. + + // Parse some JavaScript, yielding a *ast.Program and/or an ErrorList + program, err := parser.ParseFile(nil, "", `if (abc > 1) {}`, 0) + +#### func ParseFunction + +```go +func ParseFunction(parameterList, body string) (*ast.FunctionLiteral, error) +``` +ParseFunction parses a given parameter list and body as a function and returns +the corresponding ast.FunctionLiteral node. + +The parameter list, if any, should be a comma-separated list of identifiers. + +#### func ReadSource + +```go +func ReadSource(filename string, src interface{}) ([]byte, error) +``` + +#### func TransformRegExp + +```go +func TransformRegExp(pattern string) (string, error) +``` +TransformRegExp transforms a JavaScript pattern into a Go "regexp" pattern. + +re2 (Go) cannot do backtracking, so the presence of a lookahead (?=) (?!) or +backreference (\1, \2, ...) will cause an error. + +re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript +definition, on the other hand, also includes \v, Unicode "Separator, Space", +etc. + +If the pattern is invalid (not valid even in JavaScript), then this function +returns the empty string and an error. + +If the pattern is valid, but incompatible (contains a lookahead or +backreference), then this function returns the transformation (a non-empty +string) AND an error. + +#### type Error + +```go +type Error struct { + Position file.Position + Message string +} +``` + +An Error represents a parsing error. It includes the position where the error +occurred and a message/description. + +#### func (Error) Error + +```go +func (self Error) Error() string +``` + +#### type ErrorList + +```go +type ErrorList []*Error +``` + +ErrorList is a list of *Errors. + +#### func (*ErrorList) Add + +```go +func (self *ErrorList) Add(position file.Position, msg string) +``` +Add adds an Error with given position and message to an ErrorList. + +#### func (ErrorList) Err + +```go +func (self ErrorList) Err() error +``` +Err returns an error equivalent to this ErrorList. If the list is empty, Err +returns nil. + +#### func (ErrorList) Error + +```go +func (self ErrorList) Error() string +``` +Error implements the Error interface. + +#### func (ErrorList) Len + +```go +func (self ErrorList) Len() int +``` + +#### func (ErrorList) Less + +```go +func (self ErrorList) Less(i, j int) bool +``` + +#### func (*ErrorList) Reset + +```go +func (self *ErrorList) Reset() +``` +Reset resets an ErrorList to no errors. + +#### func (ErrorList) Sort + +```go +func (self ErrorList) Sort() +``` + +#### func (ErrorList) Swap + +```go +func (self ErrorList) Swap(i, j int) +``` + +#### type Mode + +```go +type Mode uint +``` + +A Mode value is a set of flags (or 0). They control optional parser +functionality. + +```go +const ( + IgnoreRegExpErrors Mode = 1 << iota // Ignore RegExp compatibility errors (allow backtracking) +) +``` + +-- +**godocdown** http://github.com/robertkrimen/godocdown diff --git a/vendor/github.com/robertkrimen/otto/parser/dbg.go b/vendor/github.com/robertkrimen/otto/parser/dbg.go new file mode 100644 index 000000000..3c5f2f698 --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/dbg.go @@ -0,0 +1,9 @@ +// This file was AUTOMATICALLY GENERATED by dbg-import (smuggol) for github.com/robertkrimen/dbg + +package parser + +import ( + Dbg "github.com/robertkrimen/otto/dbg" +) + +var dbg, dbgf = Dbg.New() diff --git a/vendor/github.com/robertkrimen/otto/parser/error.go b/vendor/github.com/robertkrimen/otto/parser/error.go new file mode 100644 index 000000000..e0f74a5cf --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/error.go @@ -0,0 +1,175 @@ +package parser + +import ( + "fmt" + "sort" + + "github.com/robertkrimen/otto/file" + "github.com/robertkrimen/otto/token" +) + +const ( + err_UnexpectedToken = "Unexpected token %v" + err_UnexpectedEndOfInput = "Unexpected end of input" + err_UnexpectedEscape = "Unexpected escape" +) + +// UnexpectedNumber: 'Unexpected number', +// UnexpectedString: 'Unexpected string', +// UnexpectedIdentifier: 'Unexpected identifier', +// UnexpectedReserved: 'Unexpected reserved word', +// NewlineAfterThrow: 'Illegal newline after throw', +// InvalidRegExp: 'Invalid regular expression', +// UnterminatedRegExp: 'Invalid regular expression: missing /', +// InvalidLHSInAssignment: 'Invalid left-hand side in assignment', +// InvalidLHSInForIn: 'Invalid left-hand side in for-in', +// MultipleDefaultsInSwitch: 'More than one default clause in switch statement', +// NoCatchOrFinally: 'Missing catch or finally after try', +// UnknownLabel: 'Undefined label \'%0\'', +// Redeclaration: '%0 \'%1\' has already been declared', +// IllegalContinue: 'Illegal continue statement', +// IllegalBreak: 'Illegal break statement', +// IllegalReturn: 'Illegal return statement', +// StrictModeWith: 'Strict mode code may not include a with statement', +// StrictCatchVariable: 'Catch variable may not be eval or arguments in strict mode', +// StrictVarName: 'Variable name may not be eval or arguments in strict mode', +// StrictParamName: 'Parameter name eval or arguments is not allowed in strict mode', +// StrictParamDupe: 'Strict mode function may not have duplicate parameter names', +// StrictFunctionName: 'Function name may not be eval or arguments in strict mode', +// StrictOctalLiteral: 'Octal literals are not allowed in strict mode.', +// StrictDelete: 'Delete of an unqualified identifier in strict mode.', +// StrictDuplicateProperty: 'Duplicate data property in object literal not allowed in strict mode', +// AccessorDataProperty: 'Object literal may not have data and accessor property with the same name', +// AccessorGetSet: 'Object literal may not have multiple get/set accessors with the same name', +// StrictLHSAssignment: 'Assignment to eval or arguments is not allowed in strict mode', +// StrictLHSPostfix: 'Postfix increment/decrement may not have eval or arguments operand in strict mode', +// StrictLHSPrefix: 'Prefix increment/decrement may not have eval or arguments operand in strict mode', +// StrictReservedWord: 'Use of future reserved word in strict mode' + +// A SyntaxError is a description of an ECMAScript syntax error. + +// An Error represents a parsing error. It includes the position where the error occurred and a message/description. +type Error struct { + Position file.Position + Message string +} + +// FIXME Should this be "SyntaxError"? + +func (self Error) Error() string { + filename := self.Position.Filename + if filename == "" { + filename = "(anonymous)" + } + return fmt.Sprintf("%s: Line %d:%d %s", + filename, + self.Position.Line, + self.Position.Column, + self.Message, + ) +} + +func (self *_parser) error(place interface{}, msg string, msgValues ...interface{}) *Error { + idx := file.Idx(0) + switch place := place.(type) { + case int: + idx = self.idxOf(place) + case file.Idx: + if place == 0 { + idx = self.idxOf(self.chrOffset) + } else { + idx = place + } + default: + panic(fmt.Errorf("error(%T, ...)", place)) + } + + position := self.position(idx) + msg = fmt.Sprintf(msg, msgValues...) + self.errors.Add(position, msg) + return self.errors[len(self.errors)-1] +} + +func (self *_parser) errorUnexpected(idx file.Idx, chr rune) error { + if chr == -1 { + return self.error(idx, err_UnexpectedEndOfInput) + } + return self.error(idx, err_UnexpectedToken, token.ILLEGAL) +} + +func (self *_parser) errorUnexpectedToken(tkn token.Token) error { + switch tkn { + case token.EOF: + return self.error(file.Idx(0), err_UnexpectedEndOfInput) + } + value := tkn.String() + switch tkn { + case token.BOOLEAN, token.NULL: + value = self.literal + case token.IDENTIFIER: + return self.error(self.idx, "Unexpected identifier") + case token.KEYWORD: + // TODO Might be a future reserved word + return self.error(self.idx, "Unexpected reserved word") + case token.NUMBER: + return self.error(self.idx, "Unexpected number") + case token.STRING: + return self.error(self.idx, "Unexpected string") + } + return self.error(self.idx, err_UnexpectedToken, value) +} + +// ErrorList is a list of *Errors. +// +type ErrorList []*Error + +// Add adds an Error with given position and message to an ErrorList. +func (self *ErrorList) Add(position file.Position, msg string) { + *self = append(*self, &Error{position, msg}) +} + +// Reset resets an ErrorList to no errors. +func (self *ErrorList) Reset() { *self = (*self)[0:0] } + +func (self ErrorList) Len() int { return len(self) } +func (self ErrorList) Swap(i, j int) { self[i], self[j] = self[j], self[i] } +func (self ErrorList) Less(i, j int) bool { + x := &self[i].Position + y := &self[j].Position + if x.Filename < y.Filename { + return true + } + if x.Filename == y.Filename { + if x.Line < y.Line { + return true + } + if x.Line == y.Line { + return x.Column < y.Column + } + } + return false +} + +func (self ErrorList) Sort() { + sort.Sort(self) +} + +// Error implements the Error interface. +func (self ErrorList) Error() string { + switch len(self) { + case 0: + return "no errors" + case 1: + return self[0].Error() + } + return fmt.Sprintf("%s (and %d more errors)", self[0].Error(), len(self)-1) +} + +// Err returns an error equivalent to this ErrorList. +// If the list is empty, Err returns nil. +func (self ErrorList) Err() error { + if len(self) == 0 { + return nil + } + return self +} diff --git a/vendor/github.com/robertkrimen/otto/parser/expression.go b/vendor/github.com/robertkrimen/otto/parser/expression.go new file mode 100644 index 000000000..63a169d40 --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/expression.go @@ -0,0 +1,1005 @@ +package parser + +import ( + "regexp" + + "github.com/robertkrimen/otto/ast" + "github.com/robertkrimen/otto/file" + "github.com/robertkrimen/otto/token" +) + +func (self *_parser) parseIdentifier() *ast.Identifier { + literal := self.literal + idx := self.idx + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.LEADING) + } + self.next() + exp := &ast.Identifier{ + Name: literal, + Idx: idx, + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(exp) + } + + return exp +} + +func (self *_parser) parsePrimaryExpression() ast.Expression { + literal := self.literal + idx := self.idx + switch self.token { + case token.IDENTIFIER: + self.next() + if len(literal) > 1 { + tkn, strict := token.IsKeyword(literal) + if tkn == token.KEYWORD { + if !strict { + self.error(idx, "Unexpected reserved word") + } + } + } + return &ast.Identifier{ + Name: literal, + Idx: idx, + } + case token.NULL: + self.next() + return &ast.NullLiteral{ + Idx: idx, + Literal: literal, + } + case token.BOOLEAN: + self.next() + value := false + switch literal { + case "true": + value = true + case "false": + value = false + default: + self.error(idx, "Illegal boolean literal") + } + return &ast.BooleanLiteral{ + Idx: idx, + Literal: literal, + Value: value, + } + case token.STRING: + self.next() + value, err := parseStringLiteral(literal[1 : len(literal)-1]) + if err != nil { + self.error(idx, err.Error()) + } + return &ast.StringLiteral{ + Idx: idx, + Literal: literal, + Value: value, + } + case token.NUMBER: + self.next() + value, err := parseNumberLiteral(literal) + if err != nil { + self.error(idx, err.Error()) + value = 0 + } + return &ast.NumberLiteral{ + Idx: idx, + Literal: literal, + Value: value, + } + case token.SLASH, token.QUOTIENT_ASSIGN: + return self.parseRegExpLiteral() + case token.LEFT_BRACE: + return self.parseObjectLiteral() + case token.LEFT_BRACKET: + return self.parseArrayLiteral() + case token.LEFT_PARENTHESIS: + self.expect(token.LEFT_PARENTHESIS) + expression := self.parseExpression() + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.expect(token.RIGHT_PARENTHESIS) + return expression + case token.THIS: + self.next() + return &ast.ThisExpression{ + Idx: idx, + } + case token.FUNCTION: + return self.parseFunction(false) + } + + self.errorUnexpectedToken(self.token) + self.nextStatement() + return &ast.BadExpression{From: idx, To: self.idx} +} + +func (self *_parser) parseRegExpLiteral() *ast.RegExpLiteral { + + offset := self.chrOffset - 1 // Opening slash already gotten + if self.token == token.QUOTIENT_ASSIGN { + offset -= 1 // = + } + idx := self.idxOf(offset) + + pattern, err := self.scanString(offset) + endOffset := self.chrOffset + + self.next() + if err == nil { + pattern = pattern[1 : len(pattern)-1] + } + + flags := "" + if self.token == token.IDENTIFIER { // gim + + flags = self.literal + self.next() + endOffset = self.chrOffset - 1 + } + + var value string + // TODO 15.10 + { + // Test during parsing that this is a valid regular expression + // Sorry, (?=) and (?!) are invalid (for now) + pattern, err := TransformRegExp(pattern) + if err != nil { + if pattern == "" || self.mode&IgnoreRegExpErrors == 0 { + self.error(idx, "Invalid regular expression: %s", err.Error()) + } + } else { + _, err = regexp.Compile(pattern) + if err != nil { + // We should not get here, ParseRegExp should catch any errors + self.error(idx, "Invalid regular expression: %s", err.Error()[22:]) // Skip redundant "parse regexp error" + } else { + value = pattern + } + } + } + + literal := self.str[offset:endOffset] + + return &ast.RegExpLiteral{ + Idx: idx, + Literal: literal, + Pattern: pattern, + Flags: flags, + Value: value, + } +} + +func (self *_parser) parseVariableDeclaration(declarationList *[]*ast.VariableExpression) ast.Expression { + + if self.token != token.IDENTIFIER { + idx := self.expect(token.IDENTIFIER) + self.nextStatement() + return &ast.BadExpression{From: idx, To: self.idx} + } + + literal := self.literal + idx := self.idx + self.next() + node := &ast.VariableExpression{ + Name: literal, + Idx: idx, + } + if self.mode&StoreComments != 0 { + self.comments.SetExpression(node) + } + + if declarationList != nil { + *declarationList = append(*declarationList, node) + } + + if self.token == token.ASSIGN { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + node.Initializer = self.parseAssignmentExpression() + } + + return node +} + +func (self *_parser) parseVariableDeclarationList(var_ file.Idx) []ast.Expression { + + var declarationList []*ast.VariableExpression // Avoid bad expressions + var list []ast.Expression + + for { + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.LEADING) + } + decl := self.parseVariableDeclaration(&declarationList) + list = append(list, decl) + if self.token != token.COMMA { + break + } + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + } + + self.scope.declare(&ast.VariableDeclaration{ + Var: var_, + List: declarationList, + }) + + return list +} + +func (self *_parser) parseObjectPropertyKey() (string, string) { + idx, tkn, literal := self.idx, self.token, self.literal + value := "" + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.KEY) + } + self.next() + + switch tkn { + case token.IDENTIFIER: + value = literal + case token.NUMBER: + var err error + _, err = parseNumberLiteral(literal) + if err != nil { + self.error(idx, err.Error()) + } else { + value = literal + } + case token.STRING: + var err error + value, err = parseStringLiteral(literal[1 : len(literal)-1]) + if err != nil { + self.error(idx, err.Error()) + } + default: + // null, false, class, etc. + if matchIdentifier.MatchString(literal) { + value = literal + } + } + return literal, value +} + +func (self *_parser) parseObjectProperty() ast.Property { + literal, value := self.parseObjectPropertyKey() + if literal == "get" && self.token != token.COLON { + idx := self.idx + _, value := self.parseObjectPropertyKey() + parameterList := self.parseFunctionParameterList() + + node := &ast.FunctionLiteral{ + Function: idx, + ParameterList: parameterList, + } + self.parseFunctionBlock(node) + return ast.Property{ + Key: value, + Kind: "get", + Value: node, + } + } else if literal == "set" && self.token != token.COLON { + idx := self.idx + _, value := self.parseObjectPropertyKey() + parameterList := self.parseFunctionParameterList() + + node := &ast.FunctionLiteral{ + Function: idx, + ParameterList: parameterList, + } + self.parseFunctionBlock(node) + return ast.Property{ + Key: value, + Kind: "set", + Value: node, + } + } + + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.COLON) + } + self.expect(token.COLON) + + exp := ast.Property{ + Key: value, + Kind: "value", + Value: self.parseAssignmentExpression(), + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(exp.Value) + } + return exp +} + +func (self *_parser) parseObjectLiteral() ast.Expression { + var value []ast.Property + idx0 := self.expect(token.LEFT_BRACE) + for self.token != token.RIGHT_BRACE && self.token != token.EOF { + value = append(value, self.parseObjectProperty()) + if self.token == token.COMMA { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + continue + } + } + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.FINAL) + } + idx1 := self.expect(token.RIGHT_BRACE) + + return &ast.ObjectLiteral{ + LeftBrace: idx0, + RightBrace: idx1, + Value: value, + } +} + +func (self *_parser) parseArrayLiteral() ast.Expression { + idx0 := self.expect(token.LEFT_BRACKET) + var value []ast.Expression + for self.token != token.RIGHT_BRACKET && self.token != token.EOF { + if self.token == token.COMMA { + // This kind of comment requires a special empty expression node. + empty := &ast.EmptyExpression{self.idx, self.idx} + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(empty) + self.comments.Unset() + } + value = append(value, empty) + self.next() + continue + } + + exp := self.parseAssignmentExpression() + + value = append(value, exp) + if self.token != token.RIGHT_BRACKET { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.expect(token.COMMA) + } + } + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.FINAL) + } + idx1 := self.expect(token.RIGHT_BRACKET) + + return &ast.ArrayLiteral{ + LeftBracket: idx0, + RightBracket: idx1, + Value: value, + } +} + +func (self *_parser) parseArgumentList() (argumentList []ast.Expression, idx0, idx1 file.Idx) { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + idx0 = self.expect(token.LEFT_PARENTHESIS) + if self.token != token.RIGHT_PARENTHESIS { + for { + exp := self.parseAssignmentExpression() + if self.mode&StoreComments != 0 { + self.comments.SetExpression(exp) + } + argumentList = append(argumentList, exp) + if self.token != token.COMMA { + break + } + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + } + } + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + idx1 = self.expect(token.RIGHT_PARENTHESIS) + return +} + +func (self *_parser) parseCallExpression(left ast.Expression) ast.Expression { + argumentList, idx0, idx1 := self.parseArgumentList() + exp := &ast.CallExpression{ + Callee: left, + LeftParenthesis: idx0, + ArgumentList: argumentList, + RightParenthesis: idx1, + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(exp) + } + return exp +} + +func (self *_parser) parseDotMember(left ast.Expression) ast.Expression { + period := self.expect(token.PERIOD) + + literal := self.literal + idx := self.idx + + if !matchIdentifier.MatchString(literal) { + self.expect(token.IDENTIFIER) + self.nextStatement() + return &ast.BadExpression{From: period, To: self.idx} + } + + self.next() + + return &ast.DotExpression{ + Left: left, + Identifier: &ast.Identifier{ + Idx: idx, + Name: literal, + }, + } +} + +func (self *_parser) parseBracketMember(left ast.Expression) ast.Expression { + idx0 := self.expect(token.LEFT_BRACKET) + member := self.parseExpression() + idx1 := self.expect(token.RIGHT_BRACKET) + return &ast.BracketExpression{ + LeftBracket: idx0, + Left: left, + Member: member, + RightBracket: idx1, + } +} + +func (self *_parser) parseNewExpression() ast.Expression { + idx := self.expect(token.NEW) + callee := self.parseLeftHandSideExpression() + node := &ast.NewExpression{ + New: idx, + Callee: callee, + } + if self.token == token.LEFT_PARENTHESIS { + argumentList, idx0, idx1 := self.parseArgumentList() + node.ArgumentList = argumentList + node.LeftParenthesis = idx0 + node.RightParenthesis = idx1 + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(node) + } + + return node +} + +func (self *_parser) parseLeftHandSideExpression() ast.Expression { + + var left ast.Expression + if self.token == token.NEW { + left = self.parseNewExpression() + } else { + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.LEADING) + self.comments.MarkPrimary() + } + left = self.parsePrimaryExpression() + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(left) + } + + for { + if self.token == token.PERIOD { + left = self.parseDotMember(left) + } else if self.token == token.LEFT_BRACKET { + left = self.parseBracketMember(left) + } else { + break + } + } + + return left +} + +func (self *_parser) parseLeftHandSideExpressionAllowCall() ast.Expression { + + allowIn := self.scope.allowIn + self.scope.allowIn = true + defer func() { + self.scope.allowIn = allowIn + }() + + var left ast.Expression + if self.token == token.NEW { + var newComments []*ast.Comment + if self.mode&StoreComments != 0 { + newComments = self.comments.FetchAll() + self.comments.MarkComments(ast.LEADING) + self.comments.MarkPrimary() + } + left = self.parseNewExpression() + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(left, newComments, ast.LEADING) + } + } else { + if self.mode&StoreComments != 0 { + self.comments.MarkComments(ast.LEADING) + self.comments.MarkPrimary() + } + left = self.parsePrimaryExpression() + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(left) + } + + for { + if self.token == token.PERIOD { + left = self.parseDotMember(left) + } else if self.token == token.LEFT_BRACKET { + left = self.parseBracketMember(left) + } else if self.token == token.LEFT_PARENTHESIS { + left = self.parseCallExpression(left) + } else { + break + } + } + + return left +} + +func (self *_parser) parsePostfixExpression() ast.Expression { + operand := self.parseLeftHandSideExpressionAllowCall() + + switch self.token { + case token.INCREMENT, token.DECREMENT: + // Make sure there is no line terminator here + if self.implicitSemicolon { + break + } + tkn := self.token + idx := self.idx + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + switch operand.(type) { + case *ast.Identifier, *ast.DotExpression, *ast.BracketExpression: + default: + self.error(idx, "Invalid left-hand side in assignment") + self.nextStatement() + return &ast.BadExpression{From: idx, To: self.idx} + } + exp := &ast.UnaryExpression{ + Operator: tkn, + Idx: idx, + Operand: operand, + Postfix: true, + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(exp) + } + + return exp + } + + return operand +} + +func (self *_parser) parseUnaryExpression() ast.Expression { + + switch self.token { + case token.PLUS, token.MINUS, token.NOT, token.BITWISE_NOT: + fallthrough + case token.DELETE, token.VOID, token.TYPEOF: + tkn := self.token + idx := self.idx + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + return &ast.UnaryExpression{ + Operator: tkn, + Idx: idx, + Operand: self.parseUnaryExpression(), + } + case token.INCREMENT, token.DECREMENT: + tkn := self.token + idx := self.idx + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + operand := self.parseUnaryExpression() + switch operand.(type) { + case *ast.Identifier, *ast.DotExpression, *ast.BracketExpression: + default: + self.error(idx, "Invalid left-hand side in assignment") + self.nextStatement() + return &ast.BadExpression{From: idx, To: self.idx} + } + return &ast.UnaryExpression{ + Operator: tkn, + Idx: idx, + Operand: operand, + } + } + + return self.parsePostfixExpression() +} + +func (self *_parser) parseMultiplicativeExpression() ast.Expression { + next := self.parseUnaryExpression + left := next() + + for self.token == token.MULTIPLY || self.token == token.SLASH || + self.token == token.REMAINDER { + tkn := self.token + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseAdditiveExpression() ast.Expression { + next := self.parseMultiplicativeExpression + left := next() + + for self.token == token.PLUS || self.token == token.MINUS { + tkn := self.token + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseShiftExpression() ast.Expression { + next := self.parseAdditiveExpression + left := next() + + for self.token == token.SHIFT_LEFT || self.token == token.SHIFT_RIGHT || + self.token == token.UNSIGNED_SHIFT_RIGHT { + tkn := self.token + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseRelationalExpression() ast.Expression { + next := self.parseShiftExpression + left := next() + + allowIn := self.scope.allowIn + self.scope.allowIn = true + defer func() { + self.scope.allowIn = allowIn + }() + + switch self.token { + case token.LESS, token.LESS_OR_EQUAL, token.GREATER, token.GREATER_OR_EQUAL: + tkn := self.token + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + exp := &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: self.parseRelationalExpression(), + Comparison: true, + } + return exp + case token.INSTANCEOF: + tkn := self.token + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + exp := &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: self.parseRelationalExpression(), + } + return exp + case token.IN: + if !allowIn { + return left + } + tkn := self.token + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + exp := &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: self.parseRelationalExpression(), + } + return exp + } + + return left +} + +func (self *_parser) parseEqualityExpression() ast.Expression { + next := self.parseRelationalExpression + left := next() + + for self.token == token.EQUAL || self.token == token.NOT_EQUAL || + self.token == token.STRICT_EQUAL || self.token == token.STRICT_NOT_EQUAL { + tkn := self.token + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + Comparison: true, + } + } + + return left +} + +func (self *_parser) parseBitwiseAndExpression() ast.Expression { + next := self.parseEqualityExpression + left := next() + + for self.token == token.AND { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + tkn := self.token + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseBitwiseExclusiveOrExpression() ast.Expression { + next := self.parseBitwiseAndExpression + left := next() + + for self.token == token.EXCLUSIVE_OR { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + tkn := self.token + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseBitwiseOrExpression() ast.Expression { + next := self.parseBitwiseExclusiveOrExpression + left := next() + + for self.token == token.OR { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + tkn := self.token + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseLogicalAndExpression() ast.Expression { + next := self.parseBitwiseOrExpression + left := next() + + for self.token == token.LOGICAL_AND { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + tkn := self.token + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseLogicalOrExpression() ast.Expression { + next := self.parseLogicalAndExpression + left := next() + + for self.token == token.LOGICAL_OR { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + tkn := self.token + self.next() + + left = &ast.BinaryExpression{ + Operator: tkn, + Left: left, + Right: next(), + } + } + + return left +} + +func (self *_parser) parseConditionlExpression() ast.Expression { + left := self.parseLogicalOrExpression() + + if self.token == token.QUESTION_MARK { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + + consequent := self.parseAssignmentExpression() + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.expect(token.COLON) + exp := &ast.ConditionalExpression{ + Test: left, + Consequent: consequent, + Alternate: self.parseAssignmentExpression(), + } + + return exp + } + + return left +} + +func (self *_parser) parseAssignmentExpression() ast.Expression { + left := self.parseConditionlExpression() + var operator token.Token + switch self.token { + case token.ASSIGN: + operator = self.token + case token.ADD_ASSIGN: + operator = token.PLUS + case token.SUBTRACT_ASSIGN: + operator = token.MINUS + case token.MULTIPLY_ASSIGN: + operator = token.MULTIPLY + case token.QUOTIENT_ASSIGN: + operator = token.SLASH + case token.REMAINDER_ASSIGN: + operator = token.REMAINDER + case token.AND_ASSIGN: + operator = token.AND + case token.AND_NOT_ASSIGN: + operator = token.AND_NOT + case token.OR_ASSIGN: + operator = token.OR + case token.EXCLUSIVE_OR_ASSIGN: + operator = token.EXCLUSIVE_OR + case token.SHIFT_LEFT_ASSIGN: + operator = token.SHIFT_LEFT + case token.SHIFT_RIGHT_ASSIGN: + operator = token.SHIFT_RIGHT + case token.UNSIGNED_SHIFT_RIGHT_ASSIGN: + operator = token.UNSIGNED_SHIFT_RIGHT + } + + if operator != 0 { + idx := self.idx + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + switch left.(type) { + case *ast.Identifier, *ast.DotExpression, *ast.BracketExpression: + default: + self.error(left.Idx0(), "Invalid left-hand side in assignment") + self.nextStatement() + return &ast.BadExpression{From: idx, To: self.idx} + } + + exp := &ast.AssignExpression{ + Left: left, + Operator: operator, + Right: self.parseAssignmentExpression(), + } + + if self.mode&StoreComments != 0 { + self.comments.SetExpression(exp) + } + + return exp + } + + return left +} + +func (self *_parser) parseExpression() ast.Expression { + next := self.parseAssignmentExpression + left := next() + + if self.token == token.COMMA { + sequence := []ast.Expression{left} + for { + if self.token != token.COMMA { + break + } + self.next() + sequence = append(sequence, next()) + } + return &ast.SequenceExpression{ + Sequence: sequence, + } + } + + return left +} diff --git a/vendor/github.com/robertkrimen/otto/parser/lexer.go b/vendor/github.com/robertkrimen/otto/parser/lexer.go new file mode 100644 index 000000000..d9d69e124 --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/lexer.go @@ -0,0 +1,866 @@ +package parser + +import ( + "bytes" + "errors" + "fmt" + "regexp" + "strconv" + "strings" + "unicode" + "unicode/utf8" + + "github.com/robertkrimen/otto/ast" + "github.com/robertkrimen/otto/file" + "github.com/robertkrimen/otto/token" +) + +type _chr struct { + value rune + width int +} + +var matchIdentifier = regexp.MustCompile(`^[$_\p{L}][$_\p{L}\d}]*$`) + +func isDecimalDigit(chr rune) bool { + return '0' <= chr && chr <= '9' +} + +func digitValue(chr rune) int { + switch { + case '0' <= chr && chr <= '9': + return int(chr - '0') + case 'a' <= chr && chr <= 'f': + return int(chr - 'a' + 10) + case 'A' <= chr && chr <= 'F': + return int(chr - 'A' + 10) + } + return 16 // Larger than any legal digit value +} + +func isDigit(chr rune, base int) bool { + return digitValue(chr) < base +} + +func isIdentifierStart(chr rune) bool { + return chr == '$' || chr == '_' || chr == '\\' || + 'a' <= chr && chr <= 'z' || 'A' <= chr && chr <= 'Z' || + chr >= utf8.RuneSelf && unicode.IsLetter(chr) +} + +func isIdentifierPart(chr rune) bool { + return chr == '$' || chr == '_' || chr == '\\' || + 'a' <= chr && chr <= 'z' || 'A' <= chr && chr <= 'Z' || + '0' <= chr && chr <= '9' || + chr >= utf8.RuneSelf && (unicode.IsLetter(chr) || unicode.IsDigit(chr)) +} + +func (self *_parser) scanIdentifier() (string, error) { + offset := self.chrOffset + parse := false + for isIdentifierPart(self.chr) { + if self.chr == '\\' { + distance := self.chrOffset - offset + self.read() + if self.chr != 'u' { + return "", fmt.Errorf("Invalid identifier escape character: %c (%s)", self.chr, string(self.chr)) + } + parse = true + var value rune + for j := 0; j < 4; j++ { + self.read() + decimal, ok := hex2decimal(byte(self.chr)) + if !ok { + return "", fmt.Errorf("Invalid identifier escape character: %c (%s)", self.chr, string(self.chr)) + } + value = value<<4 | decimal + } + if value == '\\' { + return "", fmt.Errorf("Invalid identifier escape value: %c (%s)", value, string(value)) + } else if distance == 0 { + if !isIdentifierStart(value) { + return "", fmt.Errorf("Invalid identifier escape value: %c (%s)", value, string(value)) + } + } else if distance > 0 { + if !isIdentifierPart(value) { + return "", fmt.Errorf("Invalid identifier escape value: %c (%s)", value, string(value)) + } + } + } + self.read() + } + literal := string(self.str[offset:self.chrOffset]) + if parse { + return parseStringLiteral(literal) + } + return literal, nil +} + +// 7.2 +func isLineWhiteSpace(chr rune) bool { + switch chr { + case '\u0009', '\u000b', '\u000c', '\u0020', '\u00a0', '\ufeff': + return true + case '\u000a', '\u000d', '\u2028', '\u2029': + return false + case '\u0085': + return false + } + return unicode.IsSpace(chr) +} + +// 7.3 +func isLineTerminator(chr rune) bool { + switch chr { + case '\u000a', '\u000d', '\u2028', '\u2029': + return true + } + return false +} + +func (self *_parser) scan() (tkn token.Token, literal string, idx file.Idx) { + + self.implicitSemicolon = false + + for { + self.skipWhiteSpace() + + idx = self.idxOf(self.chrOffset) + insertSemicolon := false + + switch chr := self.chr; { + case isIdentifierStart(chr): + var err error + literal, err = self.scanIdentifier() + if err != nil { + tkn = token.ILLEGAL + break + } + if len(literal) > 1 { + // Keywords are longer than 1 character, avoid lookup otherwise + var strict bool + tkn, strict = token.IsKeyword(literal) + + switch tkn { + + case 0: // Not a keyword + if literal == "true" || literal == "false" { + self.insertSemicolon = true + tkn = token.BOOLEAN + return + } else if literal == "null" { + self.insertSemicolon = true + tkn = token.NULL + return + } + + case token.KEYWORD: + tkn = token.KEYWORD + if strict { + // TODO If strict and in strict mode, then this is not a break + break + } + return + + case + token.THIS, + token.BREAK, + token.THROW, // A newline after a throw is not allowed, but we need to detect it + token.RETURN, + token.CONTINUE, + token.DEBUGGER: + self.insertSemicolon = true + return + + default: + return + + } + } + self.insertSemicolon = true + tkn = token.IDENTIFIER + return + case '0' <= chr && chr <= '9': + self.insertSemicolon = true + tkn, literal = self.scanNumericLiteral(false) + return + default: + self.read() + switch chr { + case -1: + if self.insertSemicolon { + self.insertSemicolon = false + self.implicitSemicolon = true + } + tkn = token.EOF + case '\r', '\n', '\u2028', '\u2029': + self.insertSemicolon = false + self.implicitSemicolon = true + self.comments.AtLineBreak() + continue + case ':': + tkn = token.COLON + case '.': + if digitValue(self.chr) < 10 { + insertSemicolon = true + tkn, literal = self.scanNumericLiteral(true) + } else { + tkn = token.PERIOD + } + case ',': + tkn = token.COMMA + case ';': + tkn = token.SEMICOLON + case '(': + tkn = token.LEFT_PARENTHESIS + case ')': + tkn = token.RIGHT_PARENTHESIS + insertSemicolon = true + case '[': + tkn = token.LEFT_BRACKET + case ']': + tkn = token.RIGHT_BRACKET + insertSemicolon = true + case '{': + tkn = token.LEFT_BRACE + case '}': + tkn = token.RIGHT_BRACE + insertSemicolon = true + case '+': + tkn = self.switch3(token.PLUS, token.ADD_ASSIGN, '+', token.INCREMENT) + if tkn == token.INCREMENT { + insertSemicolon = true + } + case '-': + tkn = self.switch3(token.MINUS, token.SUBTRACT_ASSIGN, '-', token.DECREMENT) + if tkn == token.DECREMENT { + insertSemicolon = true + } + case '*': + tkn = self.switch2(token.MULTIPLY, token.MULTIPLY_ASSIGN) + case '/': + if self.chr == '/' { + if self.mode&StoreComments != 0 { + literal := string(self.readSingleLineComment()) + self.comments.AddComment(ast.NewComment(literal, self.idx)) + continue + } + self.skipSingleLineComment() + continue + } else if self.chr == '*' { + if self.mode&StoreComments != 0 { + literal = string(self.readMultiLineComment()) + self.comments.AddComment(ast.NewComment(literal, self.idx)) + continue + } + self.skipMultiLineComment() + continue + } else { + // Could be division, could be RegExp literal + tkn = self.switch2(token.SLASH, token.QUOTIENT_ASSIGN) + insertSemicolon = true + } + case '%': + tkn = self.switch2(token.REMAINDER, token.REMAINDER_ASSIGN) + case '^': + tkn = self.switch2(token.EXCLUSIVE_OR, token.EXCLUSIVE_OR_ASSIGN) + case '<': + tkn = self.switch4(token.LESS, token.LESS_OR_EQUAL, '<', token.SHIFT_LEFT, token.SHIFT_LEFT_ASSIGN) + case '>': + tkn = self.switch6(token.GREATER, token.GREATER_OR_EQUAL, '>', token.SHIFT_RIGHT, token.SHIFT_RIGHT_ASSIGN, '>', token.UNSIGNED_SHIFT_RIGHT, token.UNSIGNED_SHIFT_RIGHT_ASSIGN) + case '=': + tkn = self.switch2(token.ASSIGN, token.EQUAL) + if tkn == token.EQUAL && self.chr == '=' { + self.read() + tkn = token.STRICT_EQUAL + } + case '!': + tkn = self.switch2(token.NOT, token.NOT_EQUAL) + if tkn == token.NOT_EQUAL && self.chr == '=' { + self.read() + tkn = token.STRICT_NOT_EQUAL + } + case '&': + if self.chr == '^' { + self.read() + tkn = self.switch2(token.AND_NOT, token.AND_NOT_ASSIGN) + } else { + tkn = self.switch3(token.AND, token.AND_ASSIGN, '&', token.LOGICAL_AND) + } + case '|': + tkn = self.switch3(token.OR, token.OR_ASSIGN, '|', token.LOGICAL_OR) + case '~': + tkn = token.BITWISE_NOT + case '?': + tkn = token.QUESTION_MARK + case '"', '\'': + insertSemicolon = true + tkn = token.STRING + var err error + literal, err = self.scanString(self.chrOffset - 1) + if err != nil { + tkn = token.ILLEGAL + } + default: + self.errorUnexpected(idx, chr) + tkn = token.ILLEGAL + } + } + self.insertSemicolon = insertSemicolon + return + } +} + +func (self *_parser) switch2(tkn0, tkn1 token.Token) token.Token { + if self.chr == '=' { + self.read() + return tkn1 + } + return tkn0 +} + +func (self *_parser) switch3(tkn0, tkn1 token.Token, chr2 rune, tkn2 token.Token) token.Token { + if self.chr == '=' { + self.read() + return tkn1 + } + if self.chr == chr2 { + self.read() + return tkn2 + } + return tkn0 +} + +func (self *_parser) switch4(tkn0, tkn1 token.Token, chr2 rune, tkn2, tkn3 token.Token) token.Token { + if self.chr == '=' { + self.read() + return tkn1 + } + if self.chr == chr2 { + self.read() + if self.chr == '=' { + self.read() + return tkn3 + } + return tkn2 + } + return tkn0 +} + +func (self *_parser) switch6(tkn0, tkn1 token.Token, chr2 rune, tkn2, tkn3 token.Token, chr3 rune, tkn4, tkn5 token.Token) token.Token { + if self.chr == '=' { + self.read() + return tkn1 + } + if self.chr == chr2 { + self.read() + if self.chr == '=' { + self.read() + return tkn3 + } + if self.chr == chr3 { + self.read() + if self.chr == '=' { + self.read() + return tkn5 + } + return tkn4 + } + return tkn2 + } + return tkn0 +} + +func (self *_parser) chrAt(index int) _chr { + value, width := utf8.DecodeRuneInString(self.str[index:]) + return _chr{ + value: value, + width: width, + } +} + +func (self *_parser) _peek() rune { + if self.offset+1 < self.length { + return rune(self.str[self.offset+1]) + } + return -1 +} + +func (self *_parser) read() { + if self.offset < self.length { + self.chrOffset = self.offset + chr, width := rune(self.str[self.offset]), 1 + if chr >= utf8.RuneSelf { // !ASCII + chr, width = utf8.DecodeRuneInString(self.str[self.offset:]) + if chr == utf8.RuneError && width == 1 { + self.error(self.chrOffset, "Invalid UTF-8 character") + } + } + self.offset += width + self.chr = chr + } else { + self.chrOffset = self.length + self.chr = -1 // EOF + } +} + +// This is here since the functions are so similar +func (self *_RegExp_parser) read() { + if self.offset < self.length { + self.chrOffset = self.offset + chr, width := rune(self.str[self.offset]), 1 + if chr >= utf8.RuneSelf { // !ASCII + chr, width = utf8.DecodeRuneInString(self.str[self.offset:]) + if chr == utf8.RuneError && width == 1 { + self.error(self.chrOffset, "Invalid UTF-8 character") + } + } + self.offset += width + self.chr = chr + } else { + self.chrOffset = self.length + self.chr = -1 // EOF + } +} + +func (self *_parser) readSingleLineComment() (result []rune) { + for self.chr != -1 { + self.read() + if isLineTerminator(self.chr) { + return + } + result = append(result, self.chr) + } + + // Get rid of the trailing -1 + result = result[:len(result)-1] + + return +} + +func (self *_parser) readMultiLineComment() (result []rune) { + self.read() + for self.chr >= 0 { + chr := self.chr + self.read() + if chr == '*' && self.chr == '/' { + self.read() + return + } + + result = append(result, chr) + } + + self.errorUnexpected(0, self.chr) + + return +} + +func (self *_parser) skipSingleLineComment() { + for self.chr != -1 { + self.read() + if isLineTerminator(self.chr) { + return + } + } +} + +func (self *_parser) skipMultiLineComment() { + self.read() + for self.chr >= 0 { + chr := self.chr + self.read() + if chr == '*' && self.chr == '/' { + self.read() + return + } + } + + self.errorUnexpected(0, self.chr) +} + +func (self *_parser) skipWhiteSpace() { + for { + switch self.chr { + case ' ', '\t', '\f', '\v', '\u00a0', '\ufeff': + self.read() + continue + case '\r': + if self._peek() == '\n' { + self.comments.AtLineBreak() + self.read() + } + fallthrough + case '\u2028', '\u2029', '\n': + if self.insertSemicolon { + return + } + self.comments.AtLineBreak() + self.read() + continue + } + if self.chr >= utf8.RuneSelf { + if unicode.IsSpace(self.chr) { + self.read() + continue + } + } + break + } +} + +func (self *_parser) skipLineWhiteSpace() { + for isLineWhiteSpace(self.chr) { + self.read() + } +} + +func (self *_parser) scanMantissa(base int) { + for digitValue(self.chr) < base { + self.read() + } +} + +func (self *_parser) scanEscape(quote rune) { + + var length, base uint32 + switch self.chr { + //case '0', '1', '2', '3', '4', '5', '6', '7': + // Octal: + // length, base, limit = 3, 8, 255 + case 'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', '"', '\'', '0': + self.read() + return + case '\r', '\n', '\u2028', '\u2029': + self.scanNewline() + return + case 'x': + self.read() + length, base = 2, 16 + case 'u': + self.read() + length, base = 4, 16 + default: + self.read() // Always make progress + return + } + + var value uint32 + for ; length > 0 && self.chr != quote && self.chr >= 0; length-- { + digit := uint32(digitValue(self.chr)) + if digit >= base { + break + } + value = value*base + digit + self.read() + } +} + +func (self *_parser) scanString(offset int) (string, error) { + // " ' / + quote := rune(self.str[offset]) + + for self.chr != quote { + chr := self.chr + if chr == '\n' || chr == '\r' || chr == '\u2028' || chr == '\u2029' || chr < 0 { + goto newline + } + self.read() + if chr == '\\' { + if quote == '/' { + if self.chr == '\n' || self.chr == '\r' || self.chr == '\u2028' || self.chr == '\u2029' || self.chr < 0 { + goto newline + } + self.read() + } else { + self.scanEscape(quote) + } + } else if chr == '[' && quote == '/' { + // Allow a slash (/) in a bracket character class ([...]) + // TODO Fix this, this is hacky... + quote = -1 + } else if chr == ']' && quote == -1 { + quote = '/' + } + } + + // " ' / + self.read() + + return string(self.str[offset:self.chrOffset]), nil + +newline: + self.scanNewline() + err := "String not terminated" + if quote == '/' { + err = "Invalid regular expression: missing /" + self.error(self.idxOf(offset), err) + } + return "", errors.New(err) +} + +func (self *_parser) scanNewline() { + if self.chr == '\r' { + self.read() + if self.chr != '\n' { + return + } + } + self.read() +} + +func hex2decimal(chr byte) (value rune, ok bool) { + { + chr := rune(chr) + switch { + case '0' <= chr && chr <= '9': + return chr - '0', true + case 'a' <= chr && chr <= 'f': + return chr - 'a' + 10, true + case 'A' <= chr && chr <= 'F': + return chr - 'A' + 10, true + } + return + } +} + +func parseNumberLiteral(literal string) (value interface{}, err error) { + // TODO Is Uint okay? What about -MAX_UINT + value, err = strconv.ParseInt(literal, 0, 64) + if err == nil { + return + } + + parseIntErr := err // Save this first error, just in case + + value, err = strconv.ParseFloat(literal, 64) + if err == nil { + return + } else if err.(*strconv.NumError).Err == strconv.ErrRange { + // Infinity, etc. + return value, nil + } + + err = parseIntErr + + if err.(*strconv.NumError).Err == strconv.ErrRange { + if len(literal) > 2 && literal[0] == '0' && (literal[1] == 'X' || literal[1] == 'x') { + // Could just be a very large number (e.g. 0x8000000000000000) + var value float64 + literal = literal[2:] + for _, chr := range literal { + digit := digitValue(chr) + if digit >= 16 { + goto error + } + value = value*16 + float64(digit) + } + return value, nil + } + } + +error: + return nil, errors.New("Illegal numeric literal") +} + +func parseStringLiteral(literal string) (string, error) { + // Best case scenario... + if literal == "" { + return "", nil + } + + // Slightly less-best case scenario... + if !strings.ContainsRune(literal, '\\') { + return literal, nil + } + + str := literal + buffer := bytes.NewBuffer(make([]byte, 0, 3*len(literal)/2)) + + for len(str) > 0 { + switch chr := str[0]; { + // We do not explicitly handle the case of the quote + // value, which can be: " ' / + // This assumes we're already passed a partially well-formed literal + case chr >= utf8.RuneSelf: + chr, size := utf8.DecodeRuneInString(str) + buffer.WriteRune(chr) + str = str[size:] + continue + case chr != '\\': + buffer.WriteByte(chr) + str = str[1:] + continue + } + + if len(str) <= 1 { + panic("len(str) <= 1") + } + chr := str[1] + var value rune + if chr >= utf8.RuneSelf { + str = str[1:] + var size int + value, size = utf8.DecodeRuneInString(str) + str = str[size:] // \ + <character> + } else { + str = str[2:] // \<character> + switch chr { + case 'b': + value = '\b' + case 'f': + value = '\f' + case 'n': + value = '\n' + case 'r': + value = '\r' + case 't': + value = '\t' + case 'v': + value = '\v' + case 'x', 'u': + size := 0 + switch chr { + case 'x': + size = 2 + case 'u': + size = 4 + } + if len(str) < size { + return "", fmt.Errorf("invalid escape: \\%s: len(%q) != %d", string(chr), str, size) + } + for j := 0; j < size; j++ { + decimal, ok := hex2decimal(str[j]) + if !ok { + return "", fmt.Errorf("invalid escape: \\%s: %q", string(chr), str[:size]) + } + value = value<<4 | decimal + } + str = str[size:] + if chr == 'x' { + break + } + if value > utf8.MaxRune { + panic("value > utf8.MaxRune") + } + case '0': + if len(str) == 0 || '0' > str[0] || str[0] > '7' { + value = 0 + break + } + fallthrough + case '1', '2', '3', '4', '5', '6', '7': + // TODO strict + value = rune(chr) - '0' + j := 0 + for ; j < 2; j++ { + if len(str) < j+1 { + break + } + chr := str[j] + if '0' > chr || chr > '7' { + break + } + decimal := rune(str[j]) - '0' + value = (value << 3) | decimal + } + str = str[j:] + case '\\': + value = '\\' + case '\'', '"': + value = rune(chr) + case '\r': + if len(str) > 0 { + if str[0] == '\n' { + str = str[1:] + } + } + fallthrough + case '\n': + continue + default: + value = rune(chr) + } + } + buffer.WriteRune(value) + } + + return buffer.String(), nil +} + +func (self *_parser) scanNumericLiteral(decimalPoint bool) (token.Token, string) { + + offset := self.chrOffset + tkn := token.NUMBER + + if decimalPoint { + offset-- + self.scanMantissa(10) + goto exponent + } + + if self.chr == '0' { + offset := self.chrOffset + self.read() + if self.chr == 'x' || self.chr == 'X' { + // Hexadecimal + self.read() + if isDigit(self.chr, 16) { + self.read() + } else { + return token.ILLEGAL, self.str[offset:self.chrOffset] + } + self.scanMantissa(16) + + if self.chrOffset-offset <= 2 { + // Only "0x" or "0X" + self.error(0, "Illegal hexadecimal number") + } + + goto hexadecimal + } else if self.chr == '.' { + // Float + goto float + } else { + // Octal, Float + if self.chr == 'e' || self.chr == 'E' { + goto exponent + } + self.scanMantissa(8) + if self.chr == '8' || self.chr == '9' { + return token.ILLEGAL, self.str[offset:self.chrOffset] + } + goto octal + } + } + + self.scanMantissa(10) + +float: + if self.chr == '.' { + self.read() + self.scanMantissa(10) + } + +exponent: + if self.chr == 'e' || self.chr == 'E' { + self.read() + if self.chr == '-' || self.chr == '+' { + self.read() + } + if isDecimalDigit(self.chr) { + self.read() + self.scanMantissa(10) + } else { + return token.ILLEGAL, self.str[offset:self.chrOffset] + } + } + +hexadecimal: +octal: + if isIdentifierStart(self.chr) || isDecimalDigit(self.chr) { + return token.ILLEGAL, self.str[offset:self.chrOffset] + } + + return tkn, self.str[offset:self.chrOffset] +} diff --git a/vendor/github.com/robertkrimen/otto/parser/parser.go b/vendor/github.com/robertkrimen/otto/parser/parser.go new file mode 100644 index 000000000..75b7c500c --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/parser.go @@ -0,0 +1,344 @@ +/* +Package parser implements a parser for JavaScript. + + import ( + "github.com/robertkrimen/otto/parser" + ) + +Parse and return an AST + + filename := "" // A filename is optional + src := ` + // Sample xyzzy example + (function(){ + if (3.14159 > 0) { + console.log("Hello, World."); + return; + } + + var xyzzy = NaN; + console.log("Nothing happens."); + return xyzzy; + })(); + ` + + // Parse some JavaScript, yielding a *ast.Program and/or an ErrorList + program, err := parser.ParseFile(nil, filename, src, 0) + +Warning + +The parser and AST interfaces are still works-in-progress (particularly where +node types are concerned) and may change in the future. + +*/ +package parser + +import ( + "bytes" + "encoding/base64" + "errors" + "io" + "io/ioutil" + + "github.com/robertkrimen/otto/ast" + "github.com/robertkrimen/otto/file" + "github.com/robertkrimen/otto/token" + "gopkg.in/sourcemap.v1" +) + +// A Mode value is a set of flags (or 0). They control optional parser functionality. +type Mode uint + +const ( + IgnoreRegExpErrors Mode = 1 << iota // Ignore RegExp compatibility errors (allow backtracking) + StoreComments // Store the comments from source to the comments map +) + +type _parser struct { + str string + length int + base int + + chr rune // The current character + chrOffset int // The offset of current character + offset int // The offset after current character (may be greater than 1) + + idx file.Idx // The index of token + token token.Token // The token + literal string // The literal of the token, if any + + scope *_scope + insertSemicolon bool // If we see a newline, then insert an implicit semicolon + implicitSemicolon bool // An implicit semicolon exists + + errors ErrorList + + recover struct { + // Scratch when trying to seek to the next statement, etc. + idx file.Idx + count int + } + + mode Mode + + file *file.File + + comments *ast.Comments +} + +type Parser interface { + Scan() (tkn token.Token, literal string, idx file.Idx) +} + +func _newParser(filename, src string, base int, sm *sourcemap.Consumer) *_parser { + return &_parser{ + chr: ' ', // This is set so we can start scanning by skipping whitespace + str: src, + length: len(src), + base: base, + file: file.NewFile(filename, src, base).WithSourceMap(sm), + comments: ast.NewComments(), + } +} + +// Returns a new Parser. +func NewParser(filename, src string) Parser { + return _newParser(filename, src, 1, nil) +} + +func ReadSource(filename string, src interface{}) ([]byte, error) { + if src != nil { + switch src := src.(type) { + case string: + return []byte(src), nil + case []byte: + return src, nil + case *bytes.Buffer: + if src != nil { + return src.Bytes(), nil + } + case io.Reader: + var bfr bytes.Buffer + if _, err := io.Copy(&bfr, src); err != nil { + return nil, err + } + return bfr.Bytes(), nil + } + return nil, errors.New("invalid source") + } + return ioutil.ReadFile(filename) +} + +func ReadSourceMap(filename string, src interface{}) (*sourcemap.Consumer, error) { + if src == nil { + return nil, nil + } + + switch src := src.(type) { + case string: + return sourcemap.Parse(filename, []byte(src)) + case []byte: + return sourcemap.Parse(filename, src) + case *bytes.Buffer: + if src != nil { + return sourcemap.Parse(filename, src.Bytes()) + } + case io.Reader: + var bfr bytes.Buffer + if _, err := io.Copy(&bfr, src); err != nil { + return nil, err + } + return sourcemap.Parse(filename, bfr.Bytes()) + case *sourcemap.Consumer: + return src, nil + } + + return nil, errors.New("invalid sourcemap type") +} + +func ParseFileWithSourceMap(fileSet *file.FileSet, filename string, javascriptSource, sourcemapSource interface{}, mode Mode) (*ast.Program, error) { + src, err := ReadSource(filename, javascriptSource) + if err != nil { + return nil, err + } + + if sourcemapSource == nil { + lines := bytes.Split(src, []byte("\n")) + lastLine := lines[len(lines)-1] + if bytes.HasPrefix(lastLine, []byte("//# sourceMappingURL=data:application/json")) { + bits := bytes.SplitN(lastLine, []byte(","), 2) + if len(bits) == 2 { + if d, err := base64.StdEncoding.DecodeString(string(bits[1])); err == nil { + sourcemapSource = d + } + } + } + } + + sm, err := ReadSourceMap(filename, sourcemapSource) + if err != nil { + return nil, err + } + + base := 1 + if fileSet != nil { + base = fileSet.AddFile(filename, string(src)) + } + + parser := _newParser(filename, string(src), base, sm) + parser.mode = mode + program, err := parser.parse() + program.Comments = parser.comments.CommentMap + + return program, err +} + +// ParseFile parses the source code of a single JavaScript/ECMAScript source file and returns +// the corresponding ast.Program node. +// +// If fileSet == nil, ParseFile parses source without a FileSet. +// If fileSet != nil, ParseFile first adds filename and src to fileSet. +// +// The filename argument is optional and is used for labelling errors, etc. +// +// src may be a string, a byte slice, a bytes.Buffer, or an io.Reader, but it MUST always be in UTF-8. +// +// // Parse some JavaScript, yielding a *ast.Program and/or an ErrorList +// program, err := parser.ParseFile(nil, "", `if (abc > 1) {}`, 0) +// +func ParseFile(fileSet *file.FileSet, filename string, src interface{}, mode Mode) (*ast.Program, error) { + return ParseFileWithSourceMap(fileSet, filename, src, nil, mode) +} + +// ParseFunction parses a given parameter list and body as a function and returns the +// corresponding ast.FunctionLiteral node. +// +// The parameter list, if any, should be a comma-separated list of identifiers. +// +func ParseFunction(parameterList, body string) (*ast.FunctionLiteral, error) { + + src := "(function(" + parameterList + ") {\n" + body + "\n})" + + parser := _newParser("", src, 1, nil) + program, err := parser.parse() + if err != nil { + return nil, err + } + + return program.Body[0].(*ast.ExpressionStatement).Expression.(*ast.FunctionLiteral), nil +} + +// Scan reads a single token from the source at the current offset, increments the offset and +// returns the token.Token token, a string literal representing the value of the token (if applicable) +// and it's current file.Idx index. +func (self *_parser) Scan() (tkn token.Token, literal string, idx file.Idx) { + return self.scan() +} + +func (self *_parser) slice(idx0, idx1 file.Idx) string { + from := int(idx0) - self.base + to := int(idx1) - self.base + if from >= 0 && to <= len(self.str) { + return self.str[from:to] + } + + return "" +} + +func (self *_parser) parse() (*ast.Program, error) { + self.next() + program := self.parseProgram() + if false { + self.errors.Sort() + } + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(program, self.comments.FetchAll(), ast.TRAILING) + } + + return program, self.errors.Err() +} + +func (self *_parser) next() { + self.token, self.literal, self.idx = self.scan() +} + +func (self *_parser) optionalSemicolon() { + if self.token == token.SEMICOLON { + self.next() + return + } + + if self.implicitSemicolon { + self.implicitSemicolon = false + return + } + + if self.token != token.EOF && self.token != token.RIGHT_BRACE { + self.expect(token.SEMICOLON) + } +} + +func (self *_parser) semicolon() { + if self.token != token.RIGHT_PARENTHESIS && self.token != token.RIGHT_BRACE { + if self.implicitSemicolon { + self.implicitSemicolon = false + return + } + + self.expect(token.SEMICOLON) + } +} + +func (self *_parser) idxOf(offset int) file.Idx { + return file.Idx(self.base + offset) +} + +func (self *_parser) expect(value token.Token) file.Idx { + idx := self.idx + if self.token != value { + self.errorUnexpectedToken(self.token) + } + self.next() + return idx +} + +func lineCount(str string) (int, int) { + line, last := 0, -1 + pair := false + for index, chr := range str { + switch chr { + case '\r': + line += 1 + last = index + pair = true + continue + case '\n': + if !pair { + line += 1 + } + last = index + case '\u2028', '\u2029': + line += 1 + last = index + 2 + } + pair = false + } + return line, last +} + +func (self *_parser) position(idx file.Idx) file.Position { + position := file.Position{} + offset := int(idx) - self.base + str := self.str[:offset] + position.Filename = self.file.Name() + line, last := lineCount(str) + position.Line = 1 + line + if last >= 0 { + position.Column = offset - last + } else { + position.Column = 1 + len(str) + } + + return position +} diff --git a/vendor/github.com/robertkrimen/otto/parser/regexp.go b/vendor/github.com/robertkrimen/otto/parser/regexp.go new file mode 100644 index 000000000..f614dae74 --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/regexp.go @@ -0,0 +1,358 @@ +package parser + +import ( + "bytes" + "fmt" + "strconv" +) + +type _RegExp_parser struct { + str string + length int + + chr rune // The current character + chrOffset int // The offset of current character + offset int // The offset after current character (may be greater than 1) + + errors []error + invalid bool // The input is an invalid JavaScript RegExp + + goRegexp *bytes.Buffer +} + +// TransformRegExp transforms a JavaScript pattern into a Go "regexp" pattern. +// +// re2 (Go) cannot do backtracking, so the presence of a lookahead (?=) (?!) or +// backreference (\1, \2, ...) will cause an error. +// +// re2 (Go) has a different definition for \s: [\t\n\f\r ]. +// The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. +// +// If the pattern is invalid (not valid even in JavaScript), then this function +// returns the empty string and an error. +// +// If the pattern is valid, but incompatible (contains a lookahead or backreference), +// then this function returns the transformation (a non-empty string) AND an error. +func TransformRegExp(pattern string) (string, error) { + + if pattern == "" { + return "", nil + } + + // TODO If without \, if without (?=, (?!, then another shortcut + + parser := _RegExp_parser{ + str: pattern, + length: len(pattern), + goRegexp: bytes.NewBuffer(make([]byte, 0, 3*len(pattern)/2)), + } + parser.read() // Pull in the first character + parser.scan() + var err error + if len(parser.errors) > 0 { + err = parser.errors[0] + } + if parser.invalid { + return "", err + } + + // Might not be re2 compatible, but is still a valid JavaScript RegExp + return parser.goRegexp.String(), err +} + +func (self *_RegExp_parser) scan() { + for self.chr != -1 { + switch self.chr { + case '\\': + self.read() + self.scanEscape(false) + case '(': + self.pass() + self.scanGroup() + case '[': + self.pass() + self.scanBracket() + case ')': + self.error(-1, "Unmatched ')'") + self.invalid = true + self.pass() + default: + self.pass() + } + } +} + +// (...) +func (self *_RegExp_parser) scanGroup() { + str := self.str[self.chrOffset:] + if len(str) > 1 { // A possibility of (?= or (?! + if str[0] == '?' { + if str[1] == '=' || str[1] == '!' { + self.error(-1, "re2: Invalid (%s) <lookahead>", self.str[self.chrOffset:self.chrOffset+2]) + } + } + } + for self.chr != -1 && self.chr != ')' { + switch self.chr { + case '\\': + self.read() + self.scanEscape(false) + case '(': + self.pass() + self.scanGroup() + case '[': + self.pass() + self.scanBracket() + default: + self.pass() + continue + } + } + if self.chr != ')' { + self.error(-1, "Unterminated group") + self.invalid = true + return + } + self.pass() +} + +// [...] +func (self *_RegExp_parser) scanBracket() { + for self.chr != -1 { + if self.chr == ']' { + break + } else if self.chr == '\\' { + self.read() + self.scanEscape(true) + continue + } + self.pass() + } + if self.chr != ']' { + self.error(-1, "Unterminated character class") + self.invalid = true + return + } + self.pass() +} + +// \... +func (self *_RegExp_parser) scanEscape(inClass bool) { + offset := self.chrOffset + + var length, base uint32 + switch self.chr { + + case '0', '1', '2', '3', '4', '5', '6', '7': + var value int64 + size := 0 + for { + digit := int64(digitValue(self.chr)) + if digit >= 8 { + // Not a valid digit + break + } + value = value*8 + digit + self.read() + size += 1 + } + if size == 1 { // The number of characters read + _, err := self.goRegexp.Write([]byte{'\\', byte(value) + '0'}) + if err != nil { + self.errors = append(self.errors, err) + } + if value != 0 { + // An invalid backreference + self.error(-1, "re2: Invalid \\%d <backreference>", value) + } + return + } + tmp := []byte{'\\', 'x', '0', 0} + if value >= 16 { + tmp = tmp[0:2] + } else { + tmp = tmp[0:3] + } + tmp = strconv.AppendInt(tmp, value, 16) + _, err := self.goRegexp.Write(tmp) + if err != nil { + self.errors = append(self.errors, err) + } + return + + case '8', '9': + size := 0 + for { + digit := digitValue(self.chr) + if digit >= 10 { + // Not a valid digit + break + } + self.read() + size += 1 + } + err := self.goRegexp.WriteByte('\\') + if err != nil { + self.errors = append(self.errors, err) + } + _, err = self.goRegexp.WriteString(self.str[offset:self.chrOffset]) + if err != nil { + self.errors = append(self.errors, err) + } + self.error(-1, "re2: Invalid \\%s <backreference>", self.str[offset:self.chrOffset]) + return + + case 'x': + self.read() + length, base = 2, 16 + + case 'u': + self.read() + length, base = 4, 16 + + case 'b': + if inClass { + _, err := self.goRegexp.Write([]byte{'\\', 'x', '0', '8'}) + if err != nil { + self.errors = append(self.errors, err) + } + self.read() + return + } + fallthrough + + case 'B': + fallthrough + + case 'd', 'D', 's', 'S', 'w', 'W': + // This is slightly broken, because ECMAScript + // includes \v in \s, \S, while re2 does not + fallthrough + + case '\\': + fallthrough + + case 'f', 'n', 'r', 't', 'v': + err := self.goRegexp.WriteByte('\\') + if err != nil { + self.errors = append(self.errors, err) + } + self.pass() + return + + case 'c': + self.read() + var value int64 + if 'a' <= self.chr && self.chr <= 'z' { + value = int64(self.chr) - 'a' + 1 + } else if 'A' <= self.chr && self.chr <= 'Z' { + value = int64(self.chr) - 'A' + 1 + } else { + err := self.goRegexp.WriteByte('c') + if err != nil { + self.errors = append(self.errors, err) + } + return + } + tmp := []byte{'\\', 'x', '0', 0} + if value >= 16 { + tmp = tmp[0:2] + } else { + tmp = tmp[0:3] + } + tmp = strconv.AppendInt(tmp, value, 16) + _, err := self.goRegexp.Write(tmp) + if err != nil { + self.errors = append(self.errors, err) + } + self.read() + return + + default: + // $ is an identifier character, so we have to have + // a special case for it here + if self.chr == '$' || !isIdentifierPart(self.chr) { + // A non-identifier character needs escaping + err := self.goRegexp.WriteByte('\\') + if err != nil { + self.errors = append(self.errors, err) + } + } else { + // Unescape the character for re2 + } + self.pass() + return + } + + // Otherwise, we're a \u.... or \x... + valueOffset := self.chrOffset + + var value uint32 + { + length := length + for ; length > 0; length-- { + digit := uint32(digitValue(self.chr)) + if digit >= base { + // Not a valid digit + goto skip + } + value = value*base + digit + self.read() + } + } + + if length == 4 { + _, err := self.goRegexp.Write([]byte{ + '\\', + 'x', + '{', + self.str[valueOffset+0], + self.str[valueOffset+1], + self.str[valueOffset+2], + self.str[valueOffset+3], + '}', + }) + if err != nil { + self.errors = append(self.errors, err) + } + } else if length == 2 { + _, err := self.goRegexp.Write([]byte{ + '\\', + 'x', + self.str[valueOffset+0], + self.str[valueOffset+1], + }) + if err != nil { + self.errors = append(self.errors, err) + } + } else { + // Should never, ever get here... + self.error(-1, "re2: Illegal branch in scanEscape") + goto skip + } + + return + +skip: + _, err := self.goRegexp.WriteString(self.str[offset:self.chrOffset]) + if err != nil { + self.errors = append(self.errors, err) + } +} + +func (self *_RegExp_parser) pass() { + if self.chr != -1 { + _, err := self.goRegexp.WriteRune(self.chr) + if err != nil { + self.errors = append(self.errors, err) + } + } + self.read() +} + +// TODO Better error reporting, use the offset, etc. +func (self *_RegExp_parser) error(offset int, msg string, msgValues ...interface{}) error { + err := fmt.Errorf(msg, msgValues...) + self.errors = append(self.errors, err) + return err +} diff --git a/vendor/github.com/robertkrimen/otto/parser/scope.go b/vendor/github.com/robertkrimen/otto/parser/scope.go new file mode 100644 index 000000000..e1dbdda13 --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/scope.go @@ -0,0 +1,44 @@ +package parser + +import ( + "github.com/robertkrimen/otto/ast" +) + +type _scope struct { + outer *_scope + allowIn bool + inIteration bool + inSwitch bool + inFunction bool + declarationList []ast.Declaration + + labels []string +} + +func (self *_parser) openScope() { + self.scope = &_scope{ + outer: self.scope, + allowIn: true, + } +} + +func (self *_parser) closeScope() { + self.scope = self.scope.outer +} + +func (self *_scope) declare(declaration ast.Declaration) { + self.declarationList = append(self.declarationList, declaration) +} + +func (self *_scope) hasLabel(name string) bool { + for _, label := range self.labels { + if label == name { + return true + } + } + if self.outer != nil && !self.inFunction { + // Crossing a function boundary to look for a label is verboten + return self.outer.hasLabel(name) + } + return false +} diff --git a/vendor/github.com/robertkrimen/otto/parser/statement.go b/vendor/github.com/robertkrimen/otto/parser/statement.go new file mode 100644 index 000000000..6ff19d975 --- /dev/null +++ b/vendor/github.com/robertkrimen/otto/parser/statement.go @@ -0,0 +1,938 @@ +package parser + +import ( + "github.com/robertkrimen/otto/ast" + "github.com/robertkrimen/otto/token" +) + +func (self *_parser) parseBlockStatement() *ast.BlockStatement { + node := &ast.BlockStatement{} + + // Find comments before the leading brace + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, self.comments.FetchAll(), ast.LEADING) + self.comments.Unset() + } + + node.LeftBrace = self.expect(token.LEFT_BRACE) + node.List = self.parseStatementList() + + if self.mode&StoreComments != 0 { + self.comments.Unset() + self.comments.CommentMap.AddComments(node, self.comments.FetchAll(), ast.FINAL) + self.comments.AfterBlock() + } + + node.RightBrace = self.expect(token.RIGHT_BRACE) + + // Find comments after the trailing brace + if self.mode&StoreComments != 0 { + self.comments.ResetLineBreak() + self.comments.CommentMap.AddComments(node, self.comments.Fetch(), ast.TRAILING) + } + + return node +} + +func (self *_parser) parseEmptyStatement() ast.Statement { + idx := self.expect(token.SEMICOLON) + return &ast.EmptyStatement{Semicolon: idx} +} + +func (self *_parser) parseStatementList() (list []ast.Statement) { + for self.token != token.RIGHT_BRACE && self.token != token.EOF { + statement := self.parseStatement() + list = append(list, statement) + } + + return +} + +func (self *_parser) parseStatement() ast.Statement { + + if self.token == token.EOF { + self.errorUnexpectedToken(self.token) + return &ast.BadStatement{From: self.idx, To: self.idx + 1} + } + + if self.mode&StoreComments != 0 { + self.comments.ResetLineBreak() + } + + switch self.token { + case token.SEMICOLON: + return self.parseEmptyStatement() + case token.LEFT_BRACE: + return self.parseBlockStatement() + case token.IF: + return self.parseIfStatement() + case token.DO: + statement := self.parseDoWhileStatement() + self.comments.PostProcessNode(statement) + return statement + case token.WHILE: + return self.parseWhileStatement() + case token.FOR: + return self.parseForOrForInStatement() + case token.BREAK: + return self.parseBreakStatement() + case token.CONTINUE: + return self.parseContinueStatement() + case token.DEBUGGER: + return self.parseDebuggerStatement() + case token.WITH: + return self.parseWithStatement() + case token.VAR: + return self.parseVariableStatement() + case token.FUNCTION: + return self.parseFunctionStatement() + case token.SWITCH: + return self.parseSwitchStatement() + case token.RETURN: + return self.parseReturnStatement() + case token.THROW: + return self.parseThrowStatement() + case token.TRY: + return self.parseTryStatement() + } + + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + + expression := self.parseExpression() + + if identifier, isIdentifier := expression.(*ast.Identifier); isIdentifier && self.token == token.COLON { + // LabelledStatement + colon := self.idx + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() // : + + label := identifier.Name + for _, value := range self.scope.labels { + if label == value { + self.error(identifier.Idx0(), "Label '%s' already exists", label) + } + } + var labelComments []*ast.Comment + if self.mode&StoreComments != 0 { + labelComments = self.comments.FetchAll() + } + self.scope.labels = append(self.scope.labels, label) // Push the label + statement := self.parseStatement() + self.scope.labels = self.scope.labels[:len(self.scope.labels)-1] // Pop the label + exp := &ast.LabelledStatement{ + Label: identifier, + Colon: colon, + Statement: statement, + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(exp, labelComments, ast.LEADING) + } + + return exp + } + + self.optionalSemicolon() + + statement := &ast.ExpressionStatement{ + Expression: expression, + } + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(statement, comments, ast.LEADING) + } + return statement +} + +func (self *_parser) parseTryStatement() ast.Statement { + var tryComments []*ast.Comment + if self.mode&StoreComments != 0 { + tryComments = self.comments.FetchAll() + } + node := &ast.TryStatement{ + Try: self.expect(token.TRY), + Body: self.parseBlockStatement(), + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, tryComments, ast.LEADING) + self.comments.CommentMap.AddComments(node.Body, self.comments.FetchAll(), ast.TRAILING) + } + + if self.token == token.CATCH { + catch := self.idx + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + self.expect(token.LEFT_PARENTHESIS) + if self.token != token.IDENTIFIER { + self.expect(token.IDENTIFIER) + self.nextStatement() + return &ast.BadStatement{From: catch, To: self.idx} + } else { + identifier := self.parseIdentifier() + self.expect(token.RIGHT_PARENTHESIS) + node.Catch = &ast.CatchStatement{ + Catch: catch, + Parameter: identifier, + Body: self.parseBlockStatement(), + } + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node.Catch.Body, self.comments.FetchAll(), ast.TRAILING) + } + } + } + + if self.token == token.FINALLY { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() + if self.mode&StoreComments != 0 { + tryComments = self.comments.FetchAll() + } + + node.Finally = self.parseBlockStatement() + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node.Finally, tryComments, ast.LEADING) + } + } + + if node.Catch == nil && node.Finally == nil { + self.error(node.Try, "Missing catch or finally after try") + return &ast.BadStatement{From: node.Try, To: node.Body.Idx1()} + } + + return node +} + +func (self *_parser) parseFunctionParameterList() *ast.ParameterList { + opening := self.expect(token.LEFT_PARENTHESIS) + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + var list []*ast.Identifier + for self.token != token.RIGHT_PARENTHESIS && self.token != token.EOF { + if self.token != token.IDENTIFIER { + self.expect(token.IDENTIFIER) + } else { + identifier := self.parseIdentifier() + list = append(list, identifier) + } + if self.token != token.RIGHT_PARENTHESIS { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.expect(token.COMMA) + } + } + closing := self.expect(token.RIGHT_PARENTHESIS) + + return &ast.ParameterList{ + Opening: opening, + List: list, + Closing: closing, + } +} + +func (self *_parser) parseParameterList() (list []string) { + for self.token != token.EOF { + if self.token != token.IDENTIFIER { + self.expect(token.IDENTIFIER) + } + list = append(list, self.literal) + self.next() + if self.token != token.EOF { + self.expect(token.COMMA) + } + } + return +} + +func (self *_parser) parseFunctionStatement() *ast.FunctionStatement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + function := &ast.FunctionStatement{ + Function: self.parseFunction(true), + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(function, comments, ast.LEADING) + } + + return function +} + +func (self *_parser) parseFunction(declaration bool) *ast.FunctionLiteral { + + node := &ast.FunctionLiteral{ + Function: self.expect(token.FUNCTION), + } + + var name *ast.Identifier + if self.token == token.IDENTIFIER { + name = self.parseIdentifier() + if declaration { + self.scope.declare(&ast.FunctionDeclaration{ + Function: node, + }) + } + } else if declaration { + // Use expect error handling + self.expect(token.IDENTIFIER) + } + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + node.Name = name + node.ParameterList = self.parseFunctionParameterList() + self.parseFunctionBlock(node) + node.Source = self.slice(node.Idx0(), node.Idx1()) + + return node +} + +func (self *_parser) parseFunctionBlock(node *ast.FunctionLiteral) { + { + self.openScope() + inFunction := self.scope.inFunction + self.scope.inFunction = true + defer func() { + self.scope.inFunction = inFunction + self.closeScope() + }() + node.Body = self.parseBlockStatement() + node.DeclarationList = self.scope.declarationList + } +} + +func (self *_parser) parseDebuggerStatement() ast.Statement { + idx := self.expect(token.DEBUGGER) + + node := &ast.DebuggerStatement{ + Debugger: idx, + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, self.comments.FetchAll(), ast.TRAILING) + } + + self.semicolon() + return node +} + +func (self *_parser) parseReturnStatement() ast.Statement { + idx := self.expect(token.RETURN) + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + + if !self.scope.inFunction { + self.error(idx, "Illegal return statement") + self.nextStatement() + return &ast.BadStatement{From: idx, To: self.idx} + } + + node := &ast.ReturnStatement{ + Return: idx, + } + + if !self.implicitSemicolon && self.token != token.SEMICOLON && self.token != token.RIGHT_BRACE && self.token != token.EOF { + node.Argument = self.parseExpression() + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + } + + self.semicolon() + + return node +} + +func (self *_parser) parseThrowStatement() ast.Statement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + idx := self.expect(token.THROW) + + if self.implicitSemicolon { + if self.chr == -1 { // Hackish + self.error(idx, "Unexpected end of input") + } else { + self.error(idx, "Illegal newline after throw") + } + self.nextStatement() + return &ast.BadStatement{From: idx, To: self.idx} + } + + node := &ast.ThrowStatement{ + Argument: self.parseExpression(), + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + } + + self.semicolon() + + return node +} + +func (self *_parser) parseSwitchStatement() ast.Statement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + self.expect(token.SWITCH) + if self.mode&StoreComments != 0 { + comments = append(comments, self.comments.FetchAll()...) + } + self.expect(token.LEFT_PARENTHESIS) + node := &ast.SwitchStatement{ + Discriminant: self.parseExpression(), + Default: -1, + } + self.expect(token.RIGHT_PARENTHESIS) + if self.mode&StoreComments != 0 { + comments = append(comments, self.comments.FetchAll()...) + } + + self.expect(token.LEFT_BRACE) + + inSwitch := self.scope.inSwitch + self.scope.inSwitch = true + defer func() { + self.scope.inSwitch = inSwitch + }() + + for index := 0; self.token != token.EOF; index++ { + if self.token == token.RIGHT_BRACE { + self.next() + break + } + + clause := self.parseCaseStatement() + if clause.Test == nil { + if node.Default != -1 { + self.error(clause.Case, "Already saw a default in switch") + } + node.Default = index + } + node.Body = append(node.Body, clause) + } + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + } + + return node +} + +func (self *_parser) parseWithStatement() ast.Statement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + self.expect(token.WITH) + var withComments []*ast.Comment + if self.mode&StoreComments != 0 { + withComments = self.comments.FetchAll() + } + + self.expect(token.LEFT_PARENTHESIS) + + node := &ast.WithStatement{ + Object: self.parseExpression(), + } + self.expect(token.RIGHT_PARENTHESIS) + + if self.mode&StoreComments != 0 { + //comments = append(comments, self.comments.FetchAll()...) + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + self.comments.CommentMap.AddComments(node, withComments, ast.WITH) + } + + node.Body = self.parseStatement() + + return node +} + +func (self *_parser) parseCaseStatement() *ast.CaseStatement { + node := &ast.CaseStatement{ + Case: self.idx, + } + + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + self.comments.Unset() + } + + if self.token == token.DEFAULT { + self.next() + } else { + self.expect(token.CASE) + node.Test = self.parseExpression() + } + + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.expect(token.COLON) + + for { + if self.token == token.EOF || + self.token == token.RIGHT_BRACE || + self.token == token.CASE || + self.token == token.DEFAULT { + break + } + consequent := self.parseStatement() + node.Consequent = append(node.Consequent, consequent) + } + + // Link the comments to the case statement + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + } + + return node +} + +func (self *_parser) parseIterationStatement() ast.Statement { + inIteration := self.scope.inIteration + self.scope.inIteration = true + defer func() { + self.scope.inIteration = inIteration + }() + return self.parseStatement() +} + +func (self *_parser) parseForIn(into ast.Expression) *ast.ForInStatement { + + // Already have consumed "<into> in" + + source := self.parseExpression() + self.expect(token.RIGHT_PARENTHESIS) + body := self.parseIterationStatement() + + forin := &ast.ForInStatement{ + Into: into, + Source: source, + Body: body, + } + + return forin +} + +func (self *_parser) parseFor(initializer ast.Expression) *ast.ForStatement { + + // Already have consumed "<initializer> ;" + + var test, update ast.Expression + + if self.token != token.SEMICOLON { + test = self.parseExpression() + } + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.expect(token.SEMICOLON) + + if self.token != token.RIGHT_PARENTHESIS { + update = self.parseExpression() + } + self.expect(token.RIGHT_PARENTHESIS) + body := self.parseIterationStatement() + + forstatement := &ast.ForStatement{ + Initializer: initializer, + Test: test, + Update: update, + Body: body, + } + + return forstatement +} + +func (self *_parser) parseForOrForInStatement() ast.Statement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + idx := self.expect(token.FOR) + var forComments []*ast.Comment + if self.mode&StoreComments != 0 { + forComments = self.comments.FetchAll() + } + self.expect(token.LEFT_PARENTHESIS) + + var left []ast.Expression + + forIn := false + if self.token != token.SEMICOLON { + + allowIn := self.scope.allowIn + self.scope.allowIn = false + if self.token == token.VAR { + var_ := self.idx + var varComments []*ast.Comment + if self.mode&StoreComments != 0 { + varComments = self.comments.FetchAll() + self.comments.Unset() + } + self.next() + list := self.parseVariableDeclarationList(var_) + if len(list) == 1 && self.token == token.IN { + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.next() // in + forIn = true + left = []ast.Expression{list[0]} // There is only one declaration + } else { + left = list + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(left[0], varComments, ast.LEADING) + } + } else { + left = append(left, self.parseExpression()) + if self.token == token.IN { + self.next() + forIn = true + } + } + self.scope.allowIn = allowIn + } + + if forIn { + switch left[0].(type) { + case *ast.Identifier, *ast.DotExpression, *ast.BracketExpression, *ast.VariableExpression: + // These are all acceptable + default: + self.error(idx, "Invalid left-hand side in for-in") + self.nextStatement() + return &ast.BadStatement{From: idx, To: self.idx} + } + + forin := self.parseForIn(left[0]) + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(forin, comments, ast.LEADING) + self.comments.CommentMap.AddComments(forin, forComments, ast.FOR) + } + return forin + } + + if self.mode&StoreComments != 0 { + self.comments.Unset() + } + self.expect(token.SEMICOLON) + initializer := &ast.SequenceExpression{Sequence: left} + forstatement := self.parseFor(initializer) + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(forstatement, comments, ast.LEADING) + self.comments.CommentMap.AddComments(forstatement, forComments, ast.FOR) + } + return forstatement +} + +func (self *_parser) parseVariableStatement() *ast.VariableStatement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + idx := self.expect(token.VAR) + + list := self.parseVariableDeclarationList(idx) + + statement := &ast.VariableStatement{ + Var: idx, + List: list, + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(statement, comments, ast.LEADING) + self.comments.Unset() + } + self.semicolon() + + return statement +} + +func (self *_parser) parseDoWhileStatement() ast.Statement { + inIteration := self.scope.inIteration + self.scope.inIteration = true + defer func() { + self.scope.inIteration = inIteration + }() + + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + self.expect(token.DO) + var doComments []*ast.Comment + if self.mode&StoreComments != 0 { + doComments = self.comments.FetchAll() + } + + node := &ast.DoWhileStatement{} + if self.token == token.LEFT_BRACE { + node.Body = self.parseBlockStatement() + } else { + node.Body = self.parseStatement() + } + + self.expect(token.WHILE) + var whileComments []*ast.Comment + if self.mode&StoreComments != 0 { + whileComments = self.comments.FetchAll() + } + self.expect(token.LEFT_PARENTHESIS) + node.Test = self.parseExpression() + self.expect(token.RIGHT_PARENTHESIS) + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + self.comments.CommentMap.AddComments(node, doComments, ast.DO) + self.comments.CommentMap.AddComments(node, whileComments, ast.WHILE) + } + + return node +} + +func (self *_parser) parseWhileStatement() ast.Statement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + self.expect(token.WHILE) + + var whileComments []*ast.Comment + if self.mode&StoreComments != 0 { + whileComments = self.comments.FetchAll() + } + + self.expect(token.LEFT_PARENTHESIS) + node := &ast.WhileStatement{ + Test: self.parseExpression(), + } + self.expect(token.RIGHT_PARENTHESIS) + node.Body = self.parseIterationStatement() + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + self.comments.CommentMap.AddComments(node, whileComments, ast.WHILE) + } + + return node +} + +func (self *_parser) parseIfStatement() ast.Statement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + self.expect(token.IF) + var ifComments []*ast.Comment + if self.mode&StoreComments != 0 { + ifComments = self.comments.FetchAll() + } + + self.expect(token.LEFT_PARENTHESIS) + node := &ast.IfStatement{ + Test: self.parseExpression(), + } + self.expect(token.RIGHT_PARENTHESIS) + if self.token == token.LEFT_BRACE { + node.Consequent = self.parseBlockStatement() + } else { + node.Consequent = self.parseStatement() + } + + if self.token == token.ELSE { + self.next() + node.Alternate = self.parseStatement() + } + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(node, comments, ast.LEADING) + self.comments.CommentMap.AddComments(node, ifComments, ast.IF) + } + + return node +} + +func (self *_parser) parseSourceElement() ast.Statement { + statement := self.parseStatement() + //self.comments.Unset() + return statement +} + +func (self *_parser) parseSourceElements() []ast.Statement { + body := []ast.Statement(nil) + + for { + if self.token != token.STRING { + break + } + body = append(body, self.parseSourceElement()) + } + + for self.token != token.EOF { + body = append(body, self.parseSourceElement()) + } + + return body +} + +func (self *_parser) parseProgram() *ast.Program { + self.openScope() + defer self.closeScope() + return &ast.Program{ + Body: self.parseSourceElements(), + DeclarationList: self.scope.declarationList, + File: self.file, + } +} + +func (self *_parser) parseBreakStatement() ast.Statement { + var comments []*ast.Comment + if self.mode&StoreComments != 0 { + comments = self.comments.FetchAll() + } + idx := self.expect(token.BREAK) + semicolon := self.implicitSemicolon + if self.token == token.SEMICOLON { + semicolon = true + self.next() + } + + if semicolon || self.token == token.RIGHT_BRACE { + self.implicitSemicolon = false + if !self.scope.inIteration && !self.scope.inSwitch { + goto illegal + } + breakStatement := &ast.BranchStatement{ + Idx: idx, + Token: token.BREAK, + } + + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(breakStatement, comments, ast.LEADING) + self.comments.CommentMap.AddComments(breakStatement, self.comments.FetchAll(), ast.TRAILING) + } + + return breakStatement + } + + if self.token == token.IDENTIFIER { + identifier := self.parseIdentifier() + if !self.scope.hasLabel(identifier.Name) { + self.error(idx, "Undefined label '%s'", identifier.Name) + return &ast.BadStatement{From: idx, To: identifier.Idx1()} + } + self.semicolon() + breakStatement := &ast.BranchStatement{ + Idx: idx, + Token: token.BREAK, + Label: identifier, + } + if self.mode&StoreComments != 0 { + self.comments.CommentMap.AddComments(breakStatement, comments, ast.LEADING) + } + + return breakStatement + } + + self.expect(token.IDENTIFIER) + +illegal: + self.error(idx, "Illegal break statement") + self.nextStatement() + return &ast.BadStatement{From: idx, To: self.idx} +} + +func (self *_parser) parseContinueStatement() ast.Statement { + idx := self.expect(token.CONTINUE) + semicolon := self.implicitSemicolon + if self.token == token.SEMICOLON { + semicolon = true + self.next() + } + + if semicolon || self.token == token.RIGHT_BRACE { + self.implicitSemicolon = false + if !self.scope.inIteration { + goto illegal + } + return &ast.BranchStatement{ + Idx: idx, + Token: token.CONTINUE, + } + } + + if self.token == token.IDENTIFIER { + identifier := self.parseIdentifier() + if !self.scope.hasLabel(identifier.Name) { + self.error(idx, "Undefined label '%s'", identifier.Name) + return &ast.BadStatement{From: idx, To: identifier.Idx1()} + } + if !self.scope.inIteration { + goto illegal + } + self.semicolon() + return &ast.BranchStatement{ + Idx: idx, + Token: token.CONTINUE, + Label: identifier, + } + } + + self.expect(token.IDENTIFIER) + +illegal: + self.error(idx, "Illegal continue statement") + self.nextStatement() + return &ast.BadStatement{From: idx, To: self.idx} +} + +// Find the next statement after an error (recover) +func (self *_parser) nextStatement() { + for { + switch self.token { + case token.BREAK, token.CONTINUE, + token.FOR, token.IF, token.RETURN, token.SWITCH, + token.VAR, token.DO, token.TRY, token.WITH, + token.WHILE, token.THROW, token.CATCH, token.FINALLY: + // Return only if parser made some progress since last + // sync or if it has not reached 10 next calls without + // progress. Otherwise consume at least one token to + // avoid an endless parser loop + if self.idx == self.recover.idx && self.recover.count < 10 { + self.recover.count++ + return + } + if self.idx > self.recover.idx { + self.recover.idx = self.idx + self.recover.count = 0 + return + } + // Reaching here indicates a parser bug, likely an + // incorrect token list in this function, but it only + // leads to skipping of possibly correct code if a + // previous error is present, and thus is preferred + // over a non-terminating parse. + case token.EOF: + return + } + self.next() + } +} |