def testDivPunctuator(self):
lex=Lexer()
lex.setSrc('asd/333/=')
lex.getToken()
self.assertEqual(lex.getToken(), (TOK.DIV_PUNCTUATOR,'/'))
lex.getToken()
self.assertEqual(lex.getToken(), (TOK.DIV_PUNCTUATOR,'/='))
def testPos(self):
lex = Lexer()
lex.setSrc('\n123 {"asd"\n +\n/123/')
lex.getToken()
pos = lex.getLastTokenPos()
self.assertEqual(pos['line'], 2)
self.assertEqual(pos['column'], 1)
lex.getToken()
pos = lex.getLastTokenPos()
self.assertEqual(pos['line'], 2)
self.assertEqual(pos['column'], 5)
lex.getToken()
pos = lex.getLastTokenPos()
self.assertEqual(pos['line'], 2)
self.assertEqual(pos['column'], 6)
lex.getToken()
pos = lex.getLastTokenPos()
self.assertEqual(pos['line'], 3)
self.assertEqual(pos['column'], 2)
lex.getToken()
pos = lex.getLastTokenPos()
self.assertEqual(pos['line'], 4)
self.assertEqual(pos['column'], 1)
def testCommentToken(self):
lex = Lexer()
lex.setSrc('//asdasd')
self.assertEqual(lex.getToken(), (TOK.EOF, ''))
lex.setSrc('//')
self.assertEqual(lex.getToken(), (TOK.EOF, ''))
def testRewind(self):
lex = Lexer()
lex.setSrc('asd/ee/')
self.assertEqual(lex.getToken(),(TOK.ID, 'asd'))
lex.rewind()
self.assertEqual(lex.getToken(),(TOK.ID, 'asd'))
self.assertEqual(lex.getToken(True),(TOK.REGEXP, '/ee/'))
lex.rewind()
self.assertEqual(lex.getToken(False),(TOK.DIV_PUNCTUATOR, '/'))
def testFutureStrictReservedWords(self):
lex = Lexer()
rw = ['implements','let','private','public','yield','interface','package','protected','static']
lex.strictMode = True
lex.setSrc(' '.join(rw))
for w in rw:
self.assertEqual(lex.getToken(), (TOK.FUTURE_RESERVED , w))
lex.strictMode = False
lex.setSrc(' '.join(rw))
for w in rw:
self.assertEqual(lex.getToken(), (TOK.ID , w))
def testRegExp(self):
lex=Lexer()
lex.setSrc('asd/asddd/iuy')
lex.getToken()
self.assertEqual(lex.getToken(True), (TOK.REGEXP,'/asddd/iuy'))
lex.setSrc('/asddd/')
self.assertEqual(lex.getToken(True), (TOK.REGEXP,'/asddd/'))
lex.setSrc('/\\dasddd/')
self.assertEqual(lex.getToken(True), (TOK.REGEXP,'/\\dasddd/'))
lex.setSrc('/[asd\\sdd](e)?:(1)+[a-z,1-9]asddd/')
self.assertEqual(lex.getToken(True), (TOK.REGEXP,'/[asd\\sdd](e)?:(1)+[a-z,1-9]asddd/'))
def testNotIDStartAfterNumeric(self):
lex = Lexer()
lex.setSrc("0.233a")
self.assertEqual(lex.getToken(), (TOK.ERROR , '0.233'))
lex.setSrc("233b")
self.assertEqual(lex.getToken(), (TOK.ERROR , '233'))
lex.setSrc("0x233br")
self.assertEqual(lex.getToken(), (TOK.ERROR , '0x233b'))
def testRawComment(self):
lex = Lexer()
lex.setSrc('//sdfsdff\n//asdasd')
self.assertEqual(lex.getNext(), (TOK.SINGLE_COMMENT,'sdfsdff'))
lex.getNext()
self.assertEqual(lex.getNext(), (TOK.SINGLE_COMMENT,'asdasd'))
lex.setSrc("""//sdfdff
ttttt""")
self.assertEqual(lex.getNext(), (TOK.SINGLE_COMMENT,'sdfdff'))
lex.setSrc('/*asdasd*/')
self.assertEqual(lex.getNext(), (TOK.MULTI_COMMENT, 'asdasd'))
lex.setSrc('/*asd\nasd*/123123')
self.assertEqual(lex.getNext(), (TOK.MULTINL_COMMENT, 'asd\nasd'))
def testExponentialNumbers(self):
lex = Lexer()
lex.setSrc("22e3 22.34e33 .232E23")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '22e3'))
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '22.34e33'))
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '.232E23'))
lex.setSrc("22.34e-33 .232E+23")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '22.34e-33'))
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '.232E+23'))
lex.setSrc("0.e+0")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '0.e+0'))
def testFloatNumbers(self):
lex = Lexer()
lex.setSrc("22.34 .232")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '22.34'))
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '.232'))
lex.setSrc("0. 0.3")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '0.'))
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '0.3'))
lex.setSrc("22. 44.")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '22.'))
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '44.'))
def testSimpleNumber(self):
lex = Lexer()
lex.setSrc("3213")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '3213'))
def testZeroNumber(self):
lex = Lexer()
lex.setSrc("0")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '0'))
def testWhitespaceSkipping(self):
lex = Lexer()
lex.setSrc(" \t \v ")
self.assertEqual(lex.getToken(), (TOK.EOF , ''))
def testNull(self):
lex = Lexer()
lex.setSrc('null null')
self.assertEqual(lex.getToken(), (TOK.NULL, 'null'))
self.assertEqual(lex.getToken(), (TOK.NULL, 'null'))
def testFutureReservedWords(self):
lex = Lexer()
rw = ['class','enum','extends','super','const','export','import']
lex.setSrc(' '.join(rw))
for w in rw:
self.assertEqual(lex.getToken(), (TOK.FUTURE_RESERVED , w))
def testReservedWords(self):
lex = Lexer()
rw = ['break','do','instanceof','typeof','case','else','new','var','catch','finally','return','void','continue','for','switch','while','debugger','function','this','with','default','if','throw','delete','in','try']
lex.setSrc(' '.join(rw))
for w in rw:
self.assertEqual(lex.getToken(), (TOK.RESERVED , w))
def testStringLiteral(self):
lex = Lexer()
lex.setSrc('"asdasd" "ss\\"" \'\\s\'')
self.assertEqual(lex.getToken(), (TOK.STRING, 'asdasd'))
self.assertEqual(lex.getToken(), (TOK.STRING, 'ss"'))
self.assertEqual(lex.getToken(), (TOK.STRING, 's'))
lex.setSrc('"\\\\" "\\\'" "\\"" "\\b" "\\t" "\\n" "\\v" "\\f" "\\r"')
self.assertEqual(lex.getToken(), (TOK.STRING, '\\'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\''))
self.assertEqual(lex.getToken(), (TOK.STRING, '"'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\b'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\t'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\n'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\v'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\f'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\r'))
lex.setSrc('"asd\\\ndd"')
self.assertEqual(lex.getToken(), (TOK.STRING, 'asddd'))
lex.setSrc('"dd\\u2345" \'"s\\x34\'')
self.assertEqual(lex.getToken(), (TOK.STRING, 'dd\u2345'))
self.assertEqual(lex.getToken(), (TOK.STRING, '"s\x34'))
lex.setSrc('"\\x0A"')
self.assertEqual(lex.getToken(), (TOK.STRING, '\x0A'))
lex.setSrc("'\\0' '\\0a'")
self.assertEqual(lex.getToken(), (TOK.STRING, '\0'))
self.assertEqual(lex.getToken(), (TOK.STRING, '\0a'))
def testBool(self):
lex = Lexer()
lex.setSrc('true false')
self.assertEqual(lex.getToken(), (TOK.BOOL, 'true'))
self.assertEqual(lex.getToken(), (TOK.BOOL, 'false'))
def testHexNumbers(self):
lex = Lexer()
lex.setSrc("0x233aD")
self.assertEqual(lex.getToken(), (TOK.NUMERIC , '0x233aD'))
def testID(self):
lex = Lexer()
lex.setSrc('aA$34_a bdd')
self.assertEqual(lex.getToken(), (TOK.ID, 'aA$34_a'))
self.assertEqual(lex.getToken(), (TOK.ID, 'bdd'))
def testPunctuator(self):
lex = Lexer()
ps = ['^=','{','}','(',')','[',']','.',';',',','<','>','<=','>=','==','!=','===','!==','+','-','*','%','++','--','<<','>>','>>>','&','|','^','!','~','&&','||','?',':','=','+=','-=','*=','%=','<<=','>>=','>>>=','&=','|=','^=']
lex.setSrc(' '.join(ps))
for p in ps:
self.assertEqual(lex.getToken(), (TOK.PUNCTUATOR , p))
class Parser:
def __init__(self):
self.state = 0
self.src = ''
self.lexer = Lexer()
def lookup(self):
if not self.lookupToken or self.LTLookup == None:
self.lookupToken = self.lexer.getToken(False, True)
if self.lookupToken[0] == TOK.LT:
self.LTLookup = True
self.lookupToken = self.lexer.getToken()
else:
self.LTLookup = False
return self.lookupToken
def nextToken(self, REMode=False):
if self.lookupToken != None and not REMode:
tok = self.lookupToken
self.lookupToken = self.LTLookup = None
return tok
return self.lexer.getToken(REMode)
def reset(self):
self.lexer.setSrc(self.src)
self.lookupToken = None
self.currentNode = None
self.ASTRoot = None
self.LTLookup = None
def buildAST(self):
self.reset()
self.parseProgram()
return self.ASTRoot
def match(self, token, value=None):
if value == None:
return self.lookup()[0] == token
else:
return self.lookup()[0] == token and self.lookup()[1] == value
def error(self, msg):
pos = self.lexer.getLastTokenPos()
raise Exception(msg + ' at line ' + str(pos['line']) + ' column ' + str(pos['column']))
def expect(self, token, value=None):
if not self.match(token, value):
if value == None: value = ''
else: value = ' ' + value
self.error('Expected:' + JSLexer.tokenToStr(token, value) + ' ,got \'' + self.lookup()[1] + '\'')
return self.nextToken()
def parseProgram(self):
self.ASTRoot = AST.ProgramNode(self.parseSourceElements())
def parseFunctionDeclaration(self):
self.expect(TOK.RESERVED, 'function')
name = self.expect(TOK.ID)[1]
arguments = []
self.expect(TOK.PUNCTUATOR, '(')
if self.match(TOK.ID):
arguments.append(self.nextToken()[1])
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
arguments.append(self.expect(TOK.ID)[1])
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
statements = self.parseSourceElements()
self.expect(TOK.PUNCTUATOR, '}')
return AST.FunctionDeclaration(name, arguments, statements)
def parseSourceElement(self):
if self.matchList(FIRST.FunctionDeclaration):
return self.parseFunctionDeclaration()
return self.parseStatement()
def parseSourceElements(self):
sourceElements = []
while not self.matchList(FOLLOW.SourceElements):
sourceElements.append(self.parseSourceElement())
return sourceElements
def matchList(self, list):
token = self.lookup()
for listToken in list:
if type(listToken) == tuple:
if listToken[1] == None:
if token[0] == listToken[0]: return True
elif token[1] == listToken[1] and token[0] == listToken[0]:
return True
else:
if token[0] == listToken: return True
return False
def parseBlock(self):
statements = []
self.expect(TOK.PUNCTUATOR, '{')
while not self.match(TOK.PUNCTUATOR, '}'):
statements.append(self.parseStatement())
self.expect(TOK.PUNCTUATOR, '}')
return AST.Block(statements)
def parseStatement(self):
if self.match(TOK.PUNCTUATOR, '{'):
return self.parseBlock()
if self.match(TOK.RESERVED, 'var'):
return self.parseVariableStatement()
if self.match(TOK.PUNCTUATOR, ';'):
self.nextToken()
return AST.EmptyStatement()
if self.match(TOK.RESERVED, 'if'):
return self.parseIfStatement()
if self.match(TOK.RESERVED, 'do'):
return self.parseDoWhileStatement()
if self.match(TOK.RESERVED, 'while'):
return self.parseWhileStatement()
if self.match(TOK.RESERVED, 'for'):
return self.parseForStatement()
if self.match(TOK.RESERVED, 'continue'):
return self.parseContinueStatement()
if self.match(TOK.RESERVED, 'break'):
return self.parseBreakStatement()
if self.match(TOK.RESERVED, 'return'):
return self.parseReturnStatement()
if self.match(TOK.RESERVED, 'with'):
return self.parseWithStatement()
if self.match(TOK.RESERVED, 'switch'):
return self.parseSwitchStatement()
if self.match(TOK.RESERVED, 'throw'):
return self.parseThrowStatement()
if self.match(TOK.RESERVED, 'try'):
return self.parseTryStatement()
if self.match(TOK.RESERVED, 'debugger'):
self.nextToken()
self.expectSemicolon()
return AST.DebuggerStatement()
return self.parseLabeledOrExpressionStatement()
def unexpected(self):
token = self.lookup()
self.error('Unexpected: ' + JSLexer.tokenToStr(token))
def parseVariableStatement(self):
declarations = []
self.expect(TOK.RESERVED, 'var')
declarations = self.parseVariableDeclarationsList(False)
if type(declarations) != list: declarations = [declarations]
self.expectSemicolon()
return AST.VariableStatement(declarations)
def parseVariableDeclaration(self, noIn):
name = self.expect(TOK.ID)[1]
initializer = None
if self.match(TOK.PUNCTUATOR, '='):
self.nextToken()
initializer = self.parseAssignmentExpression(noIn)
return AST.VariableDeclaration(name, initializer)
def parseAssignmentExpression(self, noIn):
result = self.parseConditionalExpression(noIn)
if self.matchList(AssignmentOperators):
op = self.nextToken()[1]
result = AST.AssignmentExpression(result, self.parseAssignmentExpression(noIn), op)
return result
def parseLeftHandSideExpression(self):
# LeftHandSideExpression ::
# (NewExpression | MemberExpression) ...
result = None
if self.match(TOK.RESERVED, 'new'):
result = self.parseNewExpression()
else:
result = self.parseMemberExpression()
while True:
if self.match(TOK.PUNCTUATOR, '('):
args = self.parseArguments()
result = AST.Call(result, args)
elif self.match(TOK.PUNCTUATOR, '['):
self.nextToken()
property = self.parseExpression(False)
result = AST.Property(result, property)
self.expect(TOK.PUNCTUATOR, ']')
elif self.match(TOK.PUNCTUATOR, '.'):
self.nextToken()
propName = self.parseIdentifierName()
result = AST.Property(result, propName)
else:
return result
def parseNewExpression(self):
newCount = [0]
while self.match(TOK.RESERVED, 'new'):
newCount[0] += 1
self.nextToken()
result = self.parseMemberExpression(newCount)
while newCount[0]:
result = AST.New(result, [])
newCount[0] -= 1
return result
#we use array trick to pass mutable list and use modified value in caller
def parseMemberExpression(self, newCount=None):
# MemberExpression ::
#(PrimaryExpression | FunctionLiteral)
# ('[' Expression ']' | '.' Identifier | Arguments)*
result = None
if not newCount: newCount = [0]
if self.match(TOK.RESERVED, 'function'):
result = self.parseFunctionExpression()
else:
result = self.parsePrimaryExpression()
while True:
if self.match(TOK.PUNCTUATOR, '('):
if not newCount[0]: return result
args = self.parseArguments()
newCount[0] -= 1
result = AST.New(result, args)
elif self.match(TOK.PUNCTUATOR, '['):
self.nextToken()
property = self.parseExpression(False)
result = AST.Property(result, property)
self.expect(TOK.PUNCTUATOR, ']')
elif self.match(TOK.PUNCTUATOR, '.'):
self.nextToken()
propName = self.parseIdentifierName()
result = AST.Property(result, propName)
else:
return result
def parsePrimaryExpression(self):
if self.match(TOK.RESERVED, 'this'):
self.nextToken()
return AST.This()
if self.match(TOK.BOOL):
return AST.BoolLiteral(self.nextToken()[1])
if self.match(TOK.STRING):
return AST.Literal(self.nextToken()[1])
if self.match(TOK.NULL):
return AST.NullLiteral(self.nextToken()[1])
if self.match(TOK.ID):
token = self.nextToken()
return AST.Identifier(token[1])
if self.match(TOK.NUMERIC):
token = self.nextToken()
return AST.NumericLiteral(token[1])
if self.match(TOK.PUNCTUATOR, '['):
return self.parseArrayLiteral()
if self.match(TOK.PUNCTUATOR, '{'):
return self.parseObjectLiteral()
if self.match(TOK.PUNCTUATOR, '('):
self.expect(TOK.PUNCTUATOR, '(')
result = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
return result
if self.match(TOK.DIV_PUNCTUATOR):
self.rewind()#reparse as a regexp
return AST.RegExpLiteral(self.nextToken(True)[1])
self.unexpected()
def parseArguments(self):
arguments = []
self.expect(TOK.PUNCTUATOR, '(')
done = self.match(TOK.PUNCTUATOR, ')')
while not done:
arguments.append(self.parseAssignmentExpression(False))
if self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
else:
done = True
self.expect(TOK.PUNCTUATOR, ')')
return arguments
def parseArrayLiteral(self):
list = []
self.expect(TOK.PUNCTUATOR, '[')
done = self.match(TOK.PUNCTUATOR, ']')
while not done:
if self.match(TOK.PUNCTUATOR, ','):
list.append(AST.HoleLiteral())
else:
list.append(self.parseAssignmentExpression(False))
if not self.match(TOK.PUNCTUATOR, ']'):
self.expect(TOK.PUNCTUATOR, ',')
else:
done = True
self.expect(TOK.PUNCTUATOR, ']')
return AST.Array(list)
def parseObjectLiteral(self):
self.expect(TOK.PUNCTUATOR, '{')
properties = []
while not self.match(TOK.PUNCTUATOR, '}'):
if self.match(TOK.ID) or self.match(TOK.RESERVED) or self.match(TOK.FUTURE_RESERVED):
key = self.nextToken()[1]
if (key == 'get' or key == 'set') and not self.match(TOK.PUNCTUATOR, ':'):
#pass properties to parse function because of tricky parsing of getter-setter
#they must be combined to one accessor property
self.parseGetSetProperty(key != 'get', properties)
if not self.match(TOK.PUNCTUATOR, '}'): self.expect(TOK.PUNCTUATOR, ',')
continue
elif self.match(TOK.NUMERIC):
key = self.nextToken()[1]
else:
key = self.expect(TOK.STRING)[1]
self.expect(TOK.PUNCTUATOR, ':')
value = self.parseAssignmentExpression(False)
#todo: check if accessor property exists
properties.append(AST.ObjectProperty(key, value))
if not self.match(TOK.PUNCTUATOR, '}'): self.expect(TOK.PUNCTUATOR, ',')
self.expect(TOK.PUNCTUATOR, '}')
return AST.ObjectLiteral(properties)
def parseGetSetProperty(self, isSetter, properties):
paramName = getterBody = setterBody = None
if self.match(TOK.ID) or self.match(TOK.RESERVED) or self.match(TOK.FUTURE_RESERVED)\
or self.match(TOK.NUMERIC) or self.match(TOK.STRING):
key = self.nextToken()[1]
self.expect(TOK.PUNCTUATOR, '(')
if isSetter: paramName = self.expect(TOK.ID)[1]
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
if isSetter: setterBody = self.parseSourceElements()
else: getterBody = self.parseSourceElements()
self.expect(TOK.PUNCTUATOR, '}')
founded = None
for s in properties:
if s.key == key:
if type(s) != AST.ObjectGetSetProperty:
self.error('Can not have both data and accessor property with same name!')
else:
if setterBody and s.setterBody: self.error('Can not have multiple accessor property with same name!')
if getterBody and s.getter: self.error('Can not have multiple accessor property with same name!')
if isSetter:
s.setterBody = setterBody
s.paramName = paramName
else:
s.getterBody = getterBody
founded = s
break
if not founded:
properties.append(AST.ObjectGetSetProperty(key, getterBody, setterBody, paramName))
else:
self.unexpected()
def parseExpression(self, noIn):
result = self.parseAssignmentExpression(noIn)
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
result = AST.BinaryExpression(result, self.parseAssignmentExpression(noIn), ',')
return result
def parseIdentifierName(self):
if self.matchList([TOK.ID, TOK.FUTURE_RESERVED, TOK.RESERVED]):
return AST.Identifier(self.nextToken()[1])
self.unexpected()
def parsePostfixExpression(self):
result = self.parseLeftHandSideExpression()
if not self.LTAhead() and self.matchList([(TOK.PUNCTUATOR, '++'), (TOK.PUNCTUATOR, '--')]):
next = self.nextToken()[1]
result = AST.PostfixExpression(result, next)
return result
def LTAhead(self):
if self.LTLookup == None:
self.lookup()
return self.LTLookup
def parseUnaryExpression(self):
next = self.lookup()
if (next[0] == TOK.PUNCTUATOR
and (next[1] == '++' or next[1] == '--' or next[1] == '-' or next[1] == '+' or next[1] == '~' or next[1] == '!'))\
or (next[0] == TOK.RESERVED
and (next[1] == 'delete' or next[1] == 'typeof' or next[1] == 'void')):
next = self.nextToken()
return AST.UnaryExpression(self.parseUnaryExpression(), next[1])
else:
return self.parsePostfixExpression()
def parseBinaryExpression(self, noIn, precedence):
x = self.parseUnaryExpression()
for i in reversed(range(precedence, self.Precedence(self.lookup(), noIn) + 1)):
while self.Precedence(self.lookup(), noIn) == i:
op = self.nextToken()[1]
x = AST.BinaryExpression(x, self.parseBinaryExpression(noIn, i), op)
return x
#return -1 if not an binary op
def Precedence(self, token, noIn):
if token[1] == 'in' and noIn: return -1
for prec, ops in enumerate(Precedence):
for op in ops:
if op == token[1]:
return prec
return -1
def rewind(self):
self.lexer.rewind()
self.lookupToken = self.LTLookup = None
def parseConditionalExpression(self, noIn):
result = self.parseBinaryExpression(noIn, 0)
if self.match(TOK.PUNCTUATOR, '?'):
self.nextToken()
#left is always accept in
left = self.parseAssignmentExpression(False)
self.expect(TOK.PUNCTUATOR, ':')
right = self.parseAssignmentExpression(noIn)
result = AST.ConditionalExpression(result, left, right)
return result
def parseIfStatement(self):
self.expect(TOK.RESERVED, 'if')
self.expect(TOK.PUNCTUATOR, '(')
condition = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
thenStatement = self.parseStatement()
if self.match(TOK.RESERVED, 'else'):
self.nextToken()
elseStatement = self.parseStatement()
else:
elseStatement = AST.EmptyStatement()
return AST.IfStatement(condition, thenStatement, elseStatement)
def parseDoWhileStatement(self):
self.expect(TOK.RESERVED, 'do')
statement = self.parseStatement()
self.expect(TOK.RESERVED, 'while')
self.expect(TOK.PUNCTUATOR, '(')
condition = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
self.expectSemicolon()
return AST.DoWhileStatement(condition, statement)
def parseWhileStatement(self):
self.expect(TOK.RESERVED, 'while')
self.expect(TOK.PUNCTUATOR, '(')
condition = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
statement = self.parseStatement()
return AST.WhileStatement(condition, statement)
def parseForStatement(self):
condition = next = None
self.expect(TOK.RESERVED, 'for')
self.expect(TOK.PUNCTUATOR, '(')
if not self.match(TOK.PUNCTUATOR, ';'):
if self.match(TOK.RESERVED, 'var'):
self.nextToken()
init = self.parseVariableDeclarationsList(True)
if self.match(TOK.RESERVED, 'in'):
if type(init) == list:
self.error('Must be only one variable declaration in for..in statement')
self.nextToken()
enum = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
body = self.parseStatement()
return AST.ForInStatement(init, enum, body)
if type(init) == list: init = AST.Block(init)
else:
#we parse both LeftHandSideExpression and ExpressionNoIn as an ExpressionNoIn
#because ExpressionNoIn produces LHSE
#additional checks may be done after that for valid LHSE if next token is 'in'
init = self.parseExpression(True)
if self.match(TOK.RESERVED, 'in'):
self.nextToken()
enum = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
body = self.parseStatement()
return AST.ForInStatement(init, enum, body)
else:
init = AST.EmptyStatement
self.expect(TOK.PUNCTUATOR, ';')
if not self.match(TOK.PUNCTUATOR, ';'):
condition = self.parseExpression(False)
else:
condition = AST.EmptyStatement
self.expect(TOK.PUNCTUATOR, ';')
if not self.match(TOK.PUNCTUATOR, ')'):
next = self.parseExpression(False)
else:
next = AST.EmptyStatement
self.expect(TOK.PUNCTUATOR, ')')
statement = self.parseStatement()
return AST.ForStatement(init, condition, next, statement)
def parseVariableDeclarationsList(self, noIn):
declarations = [self.parseVariableDeclaration(noIn)]
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
declarations.append(self.parseVariableDeclaration(noIn))
if len(declarations) == 1: return declarations[0]
return declarations
def parseContinueStatement(self):
self.expect(TOK.RESERVED, 'continue')
label = None
if self.LTAhead() or self.match(TOK.PUNCTUATOR, ';') or self.match(TOK.EOF):
return AST.ContinueStatement(label)
label = AST.Identifier(self.expect(TOK.ID)[1])
self.expectSemicolon()
return AST.ContinueStatement(label)
def parseBreakStatement(self):
self.expect(TOK.RESERVED, 'break')
label = None
if self.LTAhead() or self.match(TOK.PUNCTUATOR, ';') or self.match(TOK.EOF):
return AST.BreakStatement(label)
label = AST.Identifier(self.expect(TOK.ID)[1])
self.expectSemicolon()
return AST.BreakStatement(label)
def parseReturnStatement(self):
self.expect(TOK.RESERVED, 'return')
result = None
if self.LTAhead() or self.match(TOK.PUNCTUATOR, ';') or self.match(TOK.EOF):
return AST.ReturnStatement(result)
result = self.parseExpression(False)
self.expectSemicolon()
return AST.ReturnStatement(result)
def parseWithStatement(self):
self.expect(TOK.RESERVED, 'with')
self.expect(TOK.PUNCTUATOR, '(')
expr = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
stmt = self.parseStatement()
return AST.WithStatement(expr, stmt)
def parseSwitchStatement(self):
self.expect(TOK.RESERVED, 'switch')
self.expect(TOK.PUNCTUATOR, '(')
expr = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
cases = []
default = [False]
while not self.match(TOK.PUNCTUATOR, '}'):
cases.append(self.parseCaseClause(default))
self.expect(TOK.PUNCTUATOR, '}')
return AST.SwitchStatement(expr, cases)
def parseCaseClause(self, default):
label = None
if self.match(TOK.RESERVED, 'default'):
if default[0]: self.error('Multiple default cases not allowed')
default[0] = True
self.nextToken()
else:
self.expect(TOK.RESERVED, 'case')
label = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ':')
statements = []
while not self.match(TOK.RESERVED, 'case') and not self.match(TOK.RESERVED, 'default') and not self.match(TOK.PUNCTUATOR, '}'):
statements.append(self.parseStatement())
return AST.CaseCause(label, statements)
def expectSemicolon(self):
if self.match(TOK.PUNCTUATOR, ';'):
return self.nextToken()
if self.LTAhead() or self.match(TOK.PUNCTUATOR, '}') or self.match(TOK.EOF):
return TOK.PUNCTUATOR, ';'
return self.expect(TOK.PUNCTUATOR, ';')
def parseThrowStatement(self):
self.expect(TOK.RESERVED, 'throw')
if self.LTAhead():
self.error('No line-terminator in throw statement allowed')
exception = self.parseExpression(False)
self.expectSemicolon()
return AST.ThrowStatement(exception)
def parseTryStatement(self):
self.expect(TOK.RESERVED, 'try')
block = self.parseBlock()
catchBlock = finBlock = None
if self.match(TOK.RESERVED,'catch'):
catchBlock = self.parseCatchClause()
if self.match(TOK.RESERVED,'finally'):
finBlock = self.parseFinallyClause()
if catchBlock == None and finBlock == None:
self.error('try statement must have catch or finally clause')
return AST.TryStatement(block, catchBlock, finBlock)
def parseCatchClause(self):
self.expect(TOK.RESERVED, 'catch')
self.expect(TOK.PUNCTUATOR, '(')
id = AST.Identifier(self.expect(TOK.ID)[1])
self.expect(TOK.PUNCTUATOR, ')')
block = self.parseBlock()
return AST.CatchClause(id,block)
def parseFinallyClause(self):
self.expect(TOK.RESERVED, 'finally')
block = self.parseBlock()
return AST.FinallyClause(block)
def parseLabeledOrExpressionStatement(self):
expr = self.parseExpression(False)
if type(expr) == AST.Identifier and self.match(TOK.PUNCTUATOR, ':'):
self.nextToken()
statement = self.parseStatement()
return AST.LabelledStatement(expr, statement)
self.expectSemicolon()
return AST.ExpressionStatement(expr)
def parseFunctionExpression(self):
self.expect(TOK.RESERVED, 'function')
name = None
if not self.match(TOK.PUNCTUATOR, '('):
name = self.expect(TOK.ID)[1]
arguments = []
self.expect(TOK.PUNCTUATOR, '(')
if self.match(TOK.ID):
arguments.append(self.nextToken()[1])
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
arguments.append(self.expect(TOK.ID)[1])
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
statements = self.parseSourceElements()
self.expect(TOK.PUNCTUATOR, '}')
return AST.FunctionExpression(name, arguments, statements)
class Parser:
def __init__(self):
self.state = 0
self.src = ''
self.lexer = Lexer()
def lookup(self):
if not self.lookupToken or self.LTLookup == None:
self.lookupToken = self.lexer.getToken(False, True)
if self.lookupToken[0] == TOK.LT:
self.LTLookup = True
self.lookupToken = self.lexer.getToken()
else:
self.LTLookup = False
return self.lookupToken
def nextToken(self, REMode=False):
if self.lookupToken != None and not REMode:
tok = self.lookupToken
self.lookupToken = self.LTLookup = None
return tok
return self.lexer.getToken(REMode)
def reset(self):
self.lexer.setSrc(self.src)
self.lookupToken = None
self.currentNode = None
self.ASTRoot = None
self.LTLookup = None
def buildAST(self):
self.reset()
self.parseProgram()
return self.ASTRoot
def match(self, token, value=None):
if value == None:
return self.lookup()[0] == token
else:
return self.lookup()[0] == token and self.lookup()[1] == value
def error(self, msg):
pos = self.lexer.getLastTokenPos()
raise Exception(msg + ' at line ' + str(pos['line']) + ' column ' +
str(pos['column']))
def expect(self, token, value=None):
if not self.match(token, value):
if value == None: value = ''
else: value = ' ' + value
self.error('Expected:' + JSLexer.tokenToStr(token, value) +
' ,got \'' + self.lookup()[1] + '\'')
return self.nextToken()
def parseProgram(self):
self.ASTRoot = AST.ProgramNode(self.parseSourceElements())
def parseFunctionDeclaration(self):
self.expect(TOK.RESERVED, 'function')
name = self.expect(TOK.ID)[1]
arguments = []
self.expect(TOK.PUNCTUATOR, '(')
if self.match(TOK.ID):
arguments.append(self.nextToken()[1])
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
arguments.append(self.expect(TOK.ID)[1])
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
statements = self.parseSourceElements()
self.expect(TOK.PUNCTUATOR, '}')
return AST.FunctionDeclaration(name, arguments, statements)
def parseSourceElement(self):
if self.matchList(FIRST.FunctionDeclaration):
return self.parseFunctionDeclaration()
return self.parseStatement()
def parseSourceElements(self):
sourceElements = []
while not self.matchList(FOLLOW.SourceElements):
sourceElements.append(self.parseSourceElement())
return sourceElements
def matchList(self, list):
token = self.lookup()
for listToken in list:
if type(listToken) == tuple:
if listToken[1] == None:
if token[0] == listToken[0]: return True
elif token[1] == listToken[1] and token[0] == listToken[0]:
return True
else:
if token[0] == listToken: return True
return False
def parseBlock(self):
statements = []
self.expect(TOK.PUNCTUATOR, '{')
while not self.match(TOK.PUNCTUATOR, '}'):
statements.append(self.parseStatement())
self.expect(TOK.PUNCTUATOR, '}')
return AST.Block(statements)
def parseStatement(self):
if self.match(TOK.PUNCTUATOR, '{'):
return self.parseBlock()
if self.match(TOK.RESERVED, 'var'):
return self.parseVariableStatement()
if self.match(TOK.PUNCTUATOR, ';'):
self.nextToken()
return AST.EmptyStatement()
if self.match(TOK.RESERVED, 'if'):
return self.parseIfStatement()
if self.match(TOK.RESERVED, 'do'):
return self.parseDoWhileStatement()
if self.match(TOK.RESERVED, 'while'):
return self.parseWhileStatement()
if self.match(TOK.RESERVED, 'for'):
return self.parseForStatement()
if self.match(TOK.RESERVED, 'continue'):
return self.parseContinueStatement()
if self.match(TOK.RESERVED, 'break'):
return self.parseBreakStatement()
if self.match(TOK.RESERVED, 'return'):
return self.parseReturnStatement()
if self.match(TOK.RESERVED, 'with'):
return self.parseWithStatement()
if self.match(TOK.RESERVED, 'switch'):
return self.parseSwitchStatement()
if self.match(TOK.RESERVED, 'throw'):
return self.parseThrowStatement()
if self.match(TOK.RESERVED, 'try'):
return self.parseTryStatement()
if self.match(TOK.RESERVED, 'debugger'):
self.nextToken()
self.expectSemicolon()
return AST.DebuggerStatement()
return self.parseLabeledOrExpressionStatement()
def unexpected(self):
token = self.lookup()
self.error('Unexpected: ' + JSLexer.tokenToStr(token))
def parseVariableStatement(self):
declarations = []
self.expect(TOK.RESERVED, 'var')
declarations = self.parseVariableDeclarationsList(False)
if type(declarations) != list: declarations = [declarations]
self.expectSemicolon()
return AST.VariableStatement(declarations)
def parseVariableDeclaration(self, noIn):
name = self.expect(TOK.ID)[1]
initializer = None
if self.match(TOK.PUNCTUATOR, '='):
self.nextToken()
initializer = self.parseAssignmentExpression(noIn)
return AST.VariableDeclaration(name, initializer)
def parseAssignmentExpression(self, noIn):
result = self.parseConditionalExpression(noIn)
if self.matchList(AssignmentOperators):
op = self.nextToken()[1]
result = AST.AssignmentExpression(
result, self.parseAssignmentExpression(noIn), op)
return result
def parseLeftHandSideExpression(self):
# LeftHandSideExpression ::
# (NewExpression | MemberExpression) ...
result = None
if self.match(TOK.RESERVED, 'new'):
result = self.parseNewExpression()
else:
result = self.parseMemberExpression()
while True:
if self.match(TOK.PUNCTUATOR, '('):
args = self.parseArguments()
result = AST.Call(result, args)
elif self.match(TOK.PUNCTUATOR, '['):
self.nextToken()
property = self.parseExpression(False)
result = AST.Property(result, property)
self.expect(TOK.PUNCTUATOR, ']')
elif self.match(TOK.PUNCTUATOR, '.'):
self.nextToken()
propName = self.parseIdentifierName()
result = AST.Property(result, propName)
else:
return result
def parseNewExpression(self):
newCount = [0]
while self.match(TOK.RESERVED, 'new'):
newCount[0] += 1
self.nextToken()
result = self.parseMemberExpression(newCount)
while newCount[0]:
result = AST.New(result, [])
newCount[0] -= 1
return result
#we use array trick to pass mutable list and use modified value in caller
def parseMemberExpression(self, newCount=None):
# MemberExpression ::
#(PrimaryExpression | FunctionLiteral)
# ('[' Expression ']' | '.' Identifier | Arguments)*
result = None
if not newCount: newCount = [0]
if self.match(TOK.RESERVED, 'function'):
result = self.parseFunctionExpression()
else:
result = self.parsePrimaryExpression()
while True:
if self.match(TOK.PUNCTUATOR, '('):
if not newCount[0]: return result
args = self.parseArguments()
newCount[0] -= 1
result = AST.New(result, args)
elif self.match(TOK.PUNCTUATOR, '['):
self.nextToken()
property = self.parseExpression(False)
result = AST.Property(result, property)
self.expect(TOK.PUNCTUATOR, ']')
elif self.match(TOK.PUNCTUATOR, '.'):
self.nextToken()
propName = self.parseIdentifierName()
result = AST.Property(result, propName)
else:
return result
def parsePrimaryExpression(self):
if self.match(TOK.RESERVED, 'this'):
self.nextToken()
return AST.This()
if self.match(TOK.BOOL):
return AST.BoolLiteral(self.nextToken()[1])
if self.match(TOK.STRING):
return AST.Literal(self.nextToken()[1])
if self.match(TOK.NULL):
return AST.NullLiteral(self.nextToken()[1])
if self.match(TOK.ID):
token = self.nextToken()
return AST.Identifier(token[1])
if self.match(TOK.NUMERIC):
token = self.nextToken()
return AST.NumericLiteral(token[1])
if self.match(TOK.PUNCTUATOR, '['):
return self.parseArrayLiteral()
if self.match(TOK.PUNCTUATOR, '{'):
return self.parseObjectLiteral()
if self.match(TOK.PUNCTUATOR, '('):
self.expect(TOK.PUNCTUATOR, '(')
result = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
return result
if self.match(TOK.DIV_PUNCTUATOR):
self.rewind() #reparse as a regexp
return AST.RegExpLiteral(self.nextToken(True)[1])
self.unexpected()
def parseArguments(self):
arguments = []
self.expect(TOK.PUNCTUATOR, '(')
done = self.match(TOK.PUNCTUATOR, ')')
while not done:
arguments.append(self.parseAssignmentExpression(False))
if self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
else:
done = True
self.expect(TOK.PUNCTUATOR, ')')
return arguments
def parseArrayLiteral(self):
list = []
self.expect(TOK.PUNCTUATOR, '[')
done = self.match(TOK.PUNCTUATOR, ']')
while not done:
if self.match(TOK.PUNCTUATOR, ','):
list.append(AST.HoleLiteral())
else:
list.append(self.parseAssignmentExpression(False))
if not self.match(TOK.PUNCTUATOR, ']'):
self.expect(TOK.PUNCTUATOR, ',')
else:
done = True
self.expect(TOK.PUNCTUATOR, ']')
return AST.Array(list)
def parseObjectLiteral(self):
self.expect(TOK.PUNCTUATOR, '{')
properties = []
while not self.match(TOK.PUNCTUATOR, '}'):
if self.match(TOK.ID) or self.match(TOK.RESERVED) or self.match(
TOK.FUTURE_RESERVED):
key = self.nextToken()[1]
if (key == 'get' or key
== 'set') and not self.match(TOK.PUNCTUATOR, ':'):
#pass properties to parse function because of tricky parsing of getter-setter
#they must be combined to one accessor property
self.parseGetSetProperty(key != 'get', properties)
if not self.match(TOK.PUNCTUATOR, '}'):
self.expect(TOK.PUNCTUATOR, ',')
continue
elif self.match(TOK.NUMERIC):
key = self.nextToken()[1]
else:
key = self.expect(TOK.STRING)[1]
self.expect(TOK.PUNCTUATOR, ':')
value = self.parseAssignmentExpression(False)
#todo: check if accessor property exists
properties.append(AST.ObjectProperty(key, value))
if not self.match(TOK.PUNCTUATOR, '}'):
self.expect(TOK.PUNCTUATOR, ',')
self.expect(TOK.PUNCTUATOR, '}')
return AST.ObjectLiteral(properties)
def parseGetSetProperty(self, isSetter, properties):
paramName = getterBody = setterBody = None
if self.match(TOK.ID) or self.match(TOK.RESERVED) or self.match(TOK.FUTURE_RESERVED)\
or self.match(TOK.NUMERIC) or self.match(TOK.STRING):
key = self.nextToken()[1]
self.expect(TOK.PUNCTUATOR, '(')
if isSetter: paramName = self.expect(TOK.ID)[1]
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
if isSetter: setterBody = self.parseSourceElements()
else: getterBody = self.parseSourceElements()
self.expect(TOK.PUNCTUATOR, '}')
founded = None
for s in properties:
if s.key == key:
if type(s) != AST.ObjectGetSetProperty:
self.error(
'Can not have both data and accessor property with same name!'
)
else:
if setterBody and s.setterBody:
self.error(
'Can not have multiple accessor property with same name!'
)
if getterBody and s.getter:
self.error(
'Can not have multiple accessor property with same name!'
)
if isSetter:
s.setterBody = setterBody
s.paramName = paramName
else:
s.getterBody = getterBody
founded = s
break
if not founded:
properties.append(
AST.ObjectGetSetProperty(key, getterBody, setterBody,
paramName))
else:
self.unexpected()
def parseExpression(self, noIn):
result = self.parseAssignmentExpression(noIn)
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
result = AST.BinaryExpression(result,
self.parseAssignmentExpression(noIn),
',')
return result
def parseIdentifierName(self):
if self.matchList([TOK.ID, TOK.FUTURE_RESERVED, TOK.RESERVED]):
return AST.Identifier(self.nextToken()[1])
self.unexpected()
def parsePostfixExpression(self):
result = self.parseLeftHandSideExpression()
if not self.LTAhead() and self.matchList([(TOK.PUNCTUATOR, '++'),
(TOK.PUNCTUATOR, '--')]):
next = self.nextToken()[1]
result = AST.PostfixExpression(result, next)
return result
def LTAhead(self):
if self.LTLookup == None:
self.lookup()
return self.LTLookup
def parseUnaryExpression(self):
next = self.lookup()
if (next[0] == TOK.PUNCTUATOR
and (next[1] == '++' or next[1] == '--' or next[1] == '-' or next[1] == '+' or next[1] == '~' or next[1] == '!'))\
or (next[0] == TOK.RESERVED
and (next[1] == 'delete' or next[1] == 'typeof' or next[1] == 'void')):
next = self.nextToken()
return AST.UnaryExpression(self.parseUnaryExpression(), next[1])
else:
return self.parsePostfixExpression()
def parseBinaryExpression(self, noIn, precedence):
x = self.parseUnaryExpression()
for i in reversed(
range(precedence,
self.Precedence(self.lookup(), noIn) + 1)):
while self.Precedence(self.lookup(), noIn) == i:
op = self.nextToken()[1]
x = AST.BinaryExpression(x,
self.parseBinaryExpression(noIn,
i), op)
return x
#return -1 if not an binary op
def Precedence(self, token, noIn):
if token[1] == 'in' and noIn: return -1
for prec, ops in enumerate(Precedence):
for op in ops:
if op == token[1]:
return prec
return -1
def rewind(self):
self.lexer.rewind()
self.lookupToken = self.LTLookup = None
def parseConditionalExpression(self, noIn):
result = self.parseBinaryExpression(noIn, 0)
if self.match(TOK.PUNCTUATOR, '?'):
self.nextToken()
#left is always accept in
left = self.parseAssignmentExpression(False)
self.expect(TOK.PUNCTUATOR, ':')
right = self.parseAssignmentExpression(noIn)
result = AST.ConditionalExpression(result, left, right)
return result
def parseIfStatement(self):
self.expect(TOK.RESERVED, 'if')
self.expect(TOK.PUNCTUATOR, '(')
condition = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
thenStatement = self.parseStatement()
if self.match(TOK.RESERVED, 'else'):
self.nextToken()
elseStatement = self.parseStatement()
else:
elseStatement = AST.EmptyStatement()
return AST.IfStatement(condition, thenStatement, elseStatement)
def parseDoWhileStatement(self):
self.expect(TOK.RESERVED, 'do')
statement = self.parseStatement()
self.expect(TOK.RESERVED, 'while')
self.expect(TOK.PUNCTUATOR, '(')
condition = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
self.expectSemicolon()
return AST.DoWhileStatement(condition, statement)
def parseWhileStatement(self):
self.expect(TOK.RESERVED, 'while')
self.expect(TOK.PUNCTUATOR, '(')
condition = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
statement = self.parseStatement()
return AST.WhileStatement(condition, statement)
def parseForStatement(self):
condition = next = None
self.expect(TOK.RESERVED, 'for')
self.expect(TOK.PUNCTUATOR, '(')
if not self.match(TOK.PUNCTUATOR, ';'):
if self.match(TOK.RESERVED, 'var'):
self.nextToken()
init = self.parseVariableDeclarationsList(True)
if self.match(TOK.RESERVED, 'in'):
if type(init) == list:
self.error(
'Must be only one variable declaration in for..in statement'
)
self.nextToken()
enum = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
body = self.parseStatement()
return AST.ForInStatement(init, enum, body)
if type(init) == list: init = AST.Block(init)
else:
#we parse both LeftHandSideExpression and ExpressionNoIn as an ExpressionNoIn
#because ExpressionNoIn produces LHSE
#additional checks may be done after that for valid LHSE if next token is 'in'
init = self.parseExpression(True)
if self.match(TOK.RESERVED, 'in'):
self.nextToken()
enum = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
body = self.parseStatement()
return AST.ForInStatement(init, enum, body)
else:
init = AST.EmptyStatement
self.expect(TOK.PUNCTUATOR, ';')
if not self.match(TOK.PUNCTUATOR, ';'):
condition = self.parseExpression(False)
else:
condition = AST.EmptyStatement
self.expect(TOK.PUNCTUATOR, ';')
if not self.match(TOK.PUNCTUATOR, ')'):
next = self.parseExpression(False)
else:
next = AST.EmptyStatement
self.expect(TOK.PUNCTUATOR, ')')
statement = self.parseStatement()
return AST.ForStatement(init, condition, next, statement)
def parseVariableDeclarationsList(self, noIn):
declarations = [self.parseVariableDeclaration(noIn)]
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
declarations.append(self.parseVariableDeclaration(noIn))
if len(declarations) == 1: return declarations[0]
return declarations
def parseContinueStatement(self):
self.expect(TOK.RESERVED, 'continue')
label = None
if self.LTAhead() or self.match(TOK.PUNCTUATOR, ';') or self.match(
TOK.EOF):
return AST.ContinueStatement(label)
label = AST.Identifier(self.expect(TOK.ID)[1])
self.expectSemicolon()
return AST.ContinueStatement(label)
def parseBreakStatement(self):
self.expect(TOK.RESERVED, 'break')
label = None
if self.LTAhead() or self.match(TOK.PUNCTUATOR, ';') or self.match(
TOK.EOF):
return AST.BreakStatement(label)
label = AST.Identifier(self.expect(TOK.ID)[1])
self.expectSemicolon()
return AST.BreakStatement(label)
def parseReturnStatement(self):
self.expect(TOK.RESERVED, 'return')
result = None
if self.LTAhead() or self.match(TOK.PUNCTUATOR, ';') or self.match(
TOK.EOF):
return AST.ReturnStatement(result)
result = self.parseExpression(False)
self.expectSemicolon()
return AST.ReturnStatement(result)
def parseWithStatement(self):
self.expect(TOK.RESERVED, 'with')
self.expect(TOK.PUNCTUATOR, '(')
expr = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
stmt = self.parseStatement()
return AST.WithStatement(expr, stmt)
def parseSwitchStatement(self):
self.expect(TOK.RESERVED, 'switch')
self.expect(TOK.PUNCTUATOR, '(')
expr = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
cases = []
default = [False]
while not self.match(TOK.PUNCTUATOR, '}'):
cases.append(self.parseCaseClause(default))
self.expect(TOK.PUNCTUATOR, '}')
return AST.SwitchStatement(expr, cases)
def parseCaseClause(self, default):
label = None
if self.match(TOK.RESERVED, 'default'):
if default[0]: self.error('Multiple default cases not allowed')
default[0] = True
self.nextToken()
else:
self.expect(TOK.RESERVED, 'case')
label = self.parseExpression(False)
self.expect(TOK.PUNCTUATOR, ':')
statements = []
while not self.match(TOK.RESERVED, 'case') and not self.match(
TOK.RESERVED, 'default') and not self.match(
TOK.PUNCTUATOR, '}'):
statements.append(self.parseStatement())
return AST.CaseCause(label, statements)
def expectSemicolon(self):
if self.match(TOK.PUNCTUATOR, ';'):
return self.nextToken()
if self.LTAhead() or self.match(TOK.PUNCTUATOR, '}') or self.match(
TOK.EOF):
return TOK.PUNCTUATOR, ';'
return self.expect(TOK.PUNCTUATOR, ';')
def parseThrowStatement(self):
self.expect(TOK.RESERVED, 'throw')
if self.LTAhead():
self.error('No line-terminator in throw statement allowed')
exception = self.parseExpression(False)
self.expectSemicolon()
return AST.ThrowStatement(exception)
def parseTryStatement(self):
self.expect(TOK.RESERVED, 'try')
block = self.parseBlock()
catchBlock = finBlock = None
if self.match(TOK.RESERVED, 'catch'):
catchBlock = self.parseCatchClause()
if self.match(TOK.RESERVED, 'finally'):
finBlock = self.parseFinallyClause()
if catchBlock == None and finBlock == None:
self.error('try statement must have catch or finally clause')
return AST.TryStatement(block, catchBlock, finBlock)
def parseCatchClause(self):
self.expect(TOK.RESERVED, 'catch')
self.expect(TOK.PUNCTUATOR, '(')
id = AST.Identifier(self.expect(TOK.ID)[1])
self.expect(TOK.PUNCTUATOR, ')')
block = self.parseBlock()
return AST.CatchClause(id, block)
def parseFinallyClause(self):
self.expect(TOK.RESERVED, 'finally')
block = self.parseBlock()
return AST.FinallyClause(block)
def parseLabeledOrExpressionStatement(self):
expr = self.parseExpression(False)
if type(expr) == AST.Identifier and self.match(TOK.PUNCTUATOR, ':'):
self.nextToken()
statement = self.parseStatement()
return AST.LabelledStatement(expr, statement)
self.expectSemicolon()
return AST.ExpressionStatement(expr)
def parseFunctionExpression(self):
self.expect(TOK.RESERVED, 'function')
name = None
if not self.match(TOK.PUNCTUATOR, '('):
name = self.expect(TOK.ID)[1]
arguments = []
self.expect(TOK.PUNCTUATOR, '(')
if self.match(TOK.ID):
arguments.append(self.nextToken()[1])
while self.match(TOK.PUNCTUATOR, ','):
self.nextToken()
arguments.append(self.expect(TOK.ID)[1])
self.expect(TOK.PUNCTUATOR, ')')
self.expect(TOK.PUNCTUATOR, '{')
statements = self.parseSourceElements()
self.expect(TOK.PUNCTUATOR, '}')
return AST.FunctionExpression(name, arguments, statements)