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# -*- coding: utf-8 -*-
# Copyright JS Foundation and other contributors, https://js.foundation/
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES
# LOSS OF USE, DATA, OR PROFITS OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
from __future__ import absolute_import, unicode_literals
from collections import deque
from .objects import Object
from .error_handler import ErrorHandler
from .scanner import Scanner, SourceLocation, Position, RegExp
from .token import Token, TokenName
class BufferEntry(Object):
def __init__(self, type, value, regex=None, range=None, loc=None):
self.type = type
self.value = value
self.regex = regex
self.range = range
self.loc = loc
class Reader(object):
def __init__(self):
self.values = []
self.curly = self.paren = -1
# A function following one of those tokens is an expression.
def beforeFunctionExpression(self, t):
return t in (
'(', '{', '[', 'in', 'typeof', 'instanceof', 'new',
'return', 'case', 'delete', 'throw', 'void',
# assignment operators
'=', '+=', '-=', '*=', '**=', '/=', '%=', '<<=', '>>=', '>>>=',
'&=', '|=', '^=', ',',
# binary/unary operators
'+', '-', '*', '**', '/', '%', '++', '--', '<<', '>>', '>>>', '&',
'|', '^', '!', '~', '&&', '||', '?', ':', '===', '==', '>=',
'<=', '<', '>', '!=', '!=='
)
# Determine if forward slash (/) is an operator or part of a regular expression
# https://github.com/mozilla/sweet.js/wiki/design
def isRegexStart(self):
if not self.values:
return True
previous = self.values[-1]
regex = previous is not None
if previous in (
'this',
']',
):
regex = False
elif previous == ')':
keyword = self.values[self.paren - 1]
regex = keyword in ('if', 'while', 'for', 'with')
elif previous == '}':
# Dividing a function by anything makes little sense,
# but we have to check for that.
regex = True
if len(self.values) >= 3 and self.values[self.curly - 3] == 'function':
# Anonymous function, e.g. function(){} /42
check = self.values[self.curly - 4]
regex = not self.beforeFunctionExpression(check) if check else False
elif len(self.values) >= 4 and self.values[self.curly - 4] == 'function':
# Named function, e.g. function f(){} /42/
check = self.values[self.curly - 5]
regex = not self.beforeFunctionExpression(check) if check else True
return regex
def append(self, token):
if token.type in (Token.Punctuator, Token.Keyword):
if token.value == '{':
self.curly = len(self.values)
elif token.value == '(':
self.paren = len(self.values)
self.values.append(token.value)
else:
self.values.append(None)
class Config(Object):
def __init__(self, tolerant=None, comment=None, range=None, loc=None, **options):
self.tolerant = tolerant
self.comment = comment
self.range = range
self.loc = loc
for k, v in options.items():
setattr(self, k, v)
class Tokenizer(object):
def __init__(self, code, options):
self.config = Config(**options)
self.errorHandler = ErrorHandler()
self.errorHandler.tolerant = self.config.tolerant
self.scanner = Scanner(code, self.errorHandler)
self.scanner.trackComment = self.config.comment
self.trackRange = self.config.range
self.trackLoc = self.config.loc
self.buffer = deque()
self.reader = Reader()
def errors(self):
return self.errorHandler.errors
def getNextToken(self):
if not self.buffer:
comments = self.scanner.scanComments()
if self.scanner.trackComment:
for e in comments:
value = self.scanner.source[e.slice[0]:e.slice[1]]
comment = BufferEntry(
type='BlockComment' if e.multiLine else 'LineComment',
value=value
)
if self.trackRange:
comment.range = e.range
if self.trackLoc:
comment.loc = e.loc
self.buffer.append(comment)
if not self.scanner.eof():
if self.trackLoc:
loc = SourceLocation(
start=Position(
line=self.scanner.lineNumber,
column=self.scanner.index - self.scanner.lineStart
),
end=Position(),
)
maybeRegex = self.scanner.source[self.scanner.index] == '/' and self.reader.isRegexStart()
if maybeRegex:
state = self.scanner.saveState()
try:
token = self.scanner.scanRegExp()
except Exception:
self.scanner.restoreState(state)
token = self.scanner.lex()
else:
token = self.scanner.lex()
self.reader.append(token)
entry = BufferEntry(
type=TokenName[token.type],
value=self.scanner.source[token.start:token.end]
)
if self.trackRange:
entry.range = [token.start, token.end]
if self.trackLoc:
loc.end = Position(
line=self.scanner.lineNumber,
column=self.scanner.index - self.scanner.lineStart
)
entry.loc = loc
if token.type is Token.RegularExpression:
entry.regex = RegExp(
pattern=token.pattern,
flags=token.flags,
)
self.buffer.append(entry)
return self.buffer.popleft() if self.buffer else None
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