"""Tokenization help for Python programs.

tokenize(readline) is a generator that breaks a stream of bytes into
Python tokens. It decodes the bytes according to PEP-0263 for
determining source file encoding.

It accepts a readline-like method which is called repeatedly to get the
next line of input (or b"" for EOF). It generates 5-tuples with these
members:

 the token type (see token.py)
 the token (a string)
 the starting (row, column) indices of the token (a 2-tuple of ints)
 the ending (row, column) indices of the token (a 2-tuple of ints)
 the original line (string)

It is designed to match the working of the Python tokenizer exactly, except
that it produces COMMENT tokens for comments and gives type OP for all
operators. Additionally, all token lists start with an ENCODING token
which tells you which encoding was used to decode the bytes stream.
"""

__author__ = 'Ka-Ping Yee <ping@lfw.org>'
__credits__ = ('GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, '
 'Skip Montanaro, Raymond Hettinger, Trent Nelson, '
 'Michael Foord')
from builtins import open as _builtin_open
from codecs import lookup, BOM_UTF8
import collections
from io import TextIOWrapper
import itertools as _itertools
import re
import sys
from token import *
from token import EXACT_TOKEN_TYPES

cookie_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)', re.ASCII)
blank_re = re.compile(br'^[ \t\f]*(?:[#\r\n]|$)', re.ASCII)

import token
__all__ = token.__all__ + ["tokenize", "generate_tokens", "detect_encoding",
 "untokenize", "TokenInfo"]
del token

class TokenInfo(collections.namedtuple('TokenInfo', 'type string start end line')):
 def __repr__(self):
 annotated_type = '%d (%s)' % (self.type, tok_name[self.type])
 return ('TokenInfo(type=%s, string=%r, start=%r, end=%r, line=%r)' %
 self._replace(type=annotated_type))

 @property
 def exact_type(self):
 if self.type == OP and self.string in EXACT_TOKEN_TYPES:
 return EXACT_TOKEN_TYPES[self.string]
 else:
 return self.type

def group(*choices): return '(' + '|'.join(choices) + ')'
def any(*choices): return group(*choices) + '*'
def maybe(*choices): return group(*choices) + '?'

# Note: we use unicode matching for names ("\w") but ascii matching for
# number literals.
Whitespace = r'[ \f\t]*'
Comment = r'#[^\r\n]*'
Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment)
Name = r'\w+'

Hexnumber = r'0[xX](?:_?[0-9a-fA-F])+'
Binnumber = r'0[bB](?:_?[01])+'
Octnumber = r'0[oO](?:_?[0-7])+'
Decnumber = r'(?:0(?:_?0)*|[1-9](?:_?[0-9])*)'
Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
Exponent = r'[eE][-+]?[0-9](?:_?[0-9])*'
Pointfloat = group(r'[0-9](?:_?[0-9])*\.(?:[0-9](?:_?[0-9])*)?',
 r'\.[0-9](?:_?[0-9])*') + maybe(Exponent)
Expfloat = r'[0-9](?:_?[0-9])*' + Exponent
Floatnumber = group(Pointfloat, Expfloat)
Imagnumber = group(r'[0-9](?:_?[0-9])*[jJ]', Floatnumber + r'[jJ]')
Number = group(Imagnumber, Floatnumber, Intnumber)

# Return the empty string, plus all of the valid string prefixes.
def _all_string_prefixes():
 # The valid string prefixes. Only contain the lower case versions,
 # and don't contain any permutations (include 'fr', but not
 # 'rf'). The various permutations will be generated.
 _valid_string_prefixes = ['b', 'r', 'u', 'f', 'br', 'fr']
 # if we add binary f-strings, add: ['fb', 'fbr']
 result = {''}
 for prefix in _valid_string_prefixes:
 for t in _itertools.permutations(prefix):
 # create a list with upper and lower versions of each
 # character
 for u in _itertools.product(*[(c, c.upper()) for c in t]):
 result.add(''.join(u))
 return result

def _compile(expr):
 return re.compile(expr, re.UNICODE)

# Note that since _all_string_prefixes includes the empty string,
# StringPrefix can be the empty string (making it optional).
StringPrefix = group(*_all_string_prefixes())

# Tail end of ' string.
Single = r"[^'\\]*(?:\\.[^'\\]*)*'"
# Tail end of " string.
Double = r'[^"\\]*(?:\\.[^"\\]*)*"'
# Tail end of ''' string.
Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''"
# Tail end of """ string.
Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""'
Triple = group(StringPrefix + "'''", StringPrefix + '"""')
# Single-line ' or " string.
String = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*'",
 StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*"')

# Sorting in reverse order puts the long operators before their prefixes.
# Otherwise if = came before ==, == would get recognized as two instances
# of =.
Special = group(*map(re.escape, sorted(EXACT_TOKEN_TYPES, reverse=True)))
Funny = group(r'\r?\n', Special)

PlainToken = group(Number, Funny, String, Name)
Token = Ignore + PlainToken

# First (or only) line of ' or " string.
ContStr = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
 group("'", r'\\\r?\n'),
 StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
 group('"', r'\\\r?\n'))
PseudoExtras = group(r'\\\r?\n|\Z', Comment, Triple)
PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)

# For a given string prefix plus quotes, endpats maps it to a regex
# to match the remainder of that string. _prefix can be empty, for
# a normal single or triple quoted string (with no prefix).
endpats = {}
for _prefix in _all_string_prefixes():
 endpats[_prefix + "'"] = Single
 endpats[_prefix + '"'] = Double
 endpats[_prefix + "'''"] = Single3
 endpats[_prefix + '"""'] = Double3

# A set of all of the single and triple quoted string prefixes,
# including the opening quotes.
single_quoted = set()
triple_quoted = set()
for t in _all_string_prefixes():
 for u in (t + '"', t + "'"):
 single_quoted.add(u)
 for u in (t + '"""', t + "'''"):
 triple_quoted.add(u)

tabsize = 8

class TokenError(Exception): pass

class StopTokenizing(Exception): pass


class Untokenizer:

 def __init__(self):
 self.tokens = []
 self.prev_row = 1
 self.prev_col = 0
 self.encoding = None

 def add_whitespace(self, start):
 row, col = start
 if row < self.prev_row or row == self.prev_row and col < self.prev_col:
 raise ValueError("start ({},{}) precedes previous end ({},{})"
 .format(row, col, self.prev_row, self.prev_col))
 row_offset = row - self.prev_row
 if row_offset:
 self.tokens.append("\\\n" * row_offset)
 self.prev_col = 0
 col_offset = col - self.prev_col
 if col_offset:
 self.tokens.append(" " * col_offset)

 def untokenize(self, iterable):
 it = iter(iterable)
 indents = []
 startline = False
 for t in it:
 if len(t) == 2:
 self.compat(t, it)
 break
 tok_type, token, start, end, line = t
 if tok_type == ENCODING:
 self.encoding = token
 continue
 if tok_type == ENDMARKER:
 break
 if tok_type == INDENT:
 indents.append(token)
 continue
 elif tok_type == DEDENT:
 indents.pop()
 self.prev_row, self.prev_col = end
 continue
 elif tok_type in (NEWLINE, NL):
 startline = True
 elif startline and indents:
 indent = indents[-1]
 if start[1] >= len(indent):
 self.tokens.append(indent)
 self.prev_col = len(indent)
 startline = False
 self.add_whitespace(start)
 self.tokens.append(token)
 self.prev_row, self.prev_col = end
 if tok_type in (NEWLINE, NL):
 self.prev_row += 1
 self.prev_col = 0
 return "".join(self.tokens)

 def compat(self, token, iterable):
 indents = []
 toks_append = self.tokens.append
 startline = token[0] in (NEWLINE, NL)
 prevstring = False

 for tok in _itertools.chain([token], iterable):
 toknum, tokval = tok[:2]
 if toknum == ENCODING:
 self.encoding = tokval
 continue

 if toknum in (NAME, NUMBER):
 tokval += ' '

 # Insert a space between two consecutive strings
 if toknum == STRING:
 if prevstring:
 tokval = ' ' + tokval
 prevstring = True
 else:
 prevstring = False

 if toknum == INDENT:
 indents.append(tokval)
 continue
 elif toknum == DEDENT:
 indents.pop()
 continue
 elif toknum in (NEWLINE, NL):
 startline = True
 elif startline and indents:
 toks_append(indents[-1])
 startline = False
 toks_append(tokval)


def untokenize(iterable):
 """Transform tokens back into Python source code.
 It returns a bytes object, encoded using the ENCODING
 token, which is the first token sequence output by tokenize.

 Each element returned by the iterable must be a token sequence
 with at least two elements, a token number and token value. If
 only two tokens are passed, the resulting output is poor.

 Round-trip invariant for full input:
 Untokenized source will match input source exactly

 Round-trip invariant for limited input:
 # Output bytes will tokenize back to the input
 t1 = [tok[:2] for tok in tokenize(f.readline)]
 newcode = untokenize(t1)
 readline = BytesIO(newcode).readline
 t2 = [tok[:2] for tok in tokenize(readline)]
 assert t1 == t2
 """
 ut = Untokenizer()
 out = ut.untokenize(iterable)
 if ut.encoding is not None:
 out = out.encode(ut.encoding)
 return out


def _get_normal_name(orig_enc):
 """Imitates get_normal_name in tokenizer.c."""
 # Only care about the first 12 characters.
 enc = orig_enc[:12].lower().replace("_", "-")
 if enc == "utf-8" or enc.startswith("utf-8-"):
 return "utf-8"
 if enc in ("latin-1", "iso-8859-1", "iso-latin-1") or \
 enc.startswith(("latin-1-", "iso-8859-1-", "iso-latin-1-")):
 return "iso-8859-1"
 return orig_enc

def detect_encoding(readline):
 """
 The detect_encoding() function is used to detect the encoding that should
 be used to decode a Python source file. It requires one argument, readline,
 in the same way as the tokenize() generator.

 It will call readline a maximum of twice, and return the encoding used
 (as a string) and a list of any lines (left as bytes) it has read in.

 It detects the encoding from the presence of a utf-8 bom or an encoding
 cookie as specified in pep-0263. If both a bom and a cookie are present,
 but disagree, a SyntaxError will be raised. If the encoding cookie is an
 invalid charset, raise a SyntaxError. Note that if a utf-8 bom is found,
 'utf-8-sig' is returned.

 If no encoding is specified, then the default of 'utf-8' will be returned.
 """
 try:
 filename = readline.__self__.name
 except AttributeError:
 filename = None
 bom_found = False
 encoding = None
 default = 'utf-8'
 def read_or_stop():
 try:
 return readline()
 except StopIteration:
 return b''

 def find_cookie(line):
 try:
 # Decode as UTF-8. Either the line is an encoding declaration,
 # in which case it should be pure ASCII, or it must be UTF-8
 # per default encoding.
 line_string = line.decode('utf-8')
 except UnicodeDecodeError:
 msg = "invalid or missing encoding declaration"
 if filename is not None:
 msg = '{} for {!r}'.format(msg, filename)
 raise SyntaxError(msg)

 match = cookie_re.match(line_string)
 if not match:
 return None
 encoding = _get_normal_name(match.group(1))
 try:
 codec = lookup(encoding)
 except LookupError:
 # This behaviour mimics the Python interpreter
 if filename is None:
 msg = "unknown encoding: " + encoding
 else:
 msg = "unknown encoding for {!r}: {}".format(filename,
 encoding)
 raise SyntaxError(msg)

 if bom_found:
 if encoding != 'utf-8':
 # This behaviour mimics the Python interpreter
 if filename is None:
 msg = 'encoding problem: utf-8'
 else:
 msg = 'encoding problem for {!r}: utf-8'.format(filename)
 raise SyntaxError(msg)
 encoding += '-sig'
 return encoding

 first = read_or_stop()
 if first.startswith(BOM_UTF8):
 bom_found = True
 first = first[3:]
 default = 'utf-8-sig'
 if not first:
 return default, []

 encoding = find_cookie(first)
 if encoding:
 return encoding, [first]
 if not blank_re.match(first):
 return default, [first]

 second = read_or_stop()
 if not second:
 return default, [first]

 encoding = find_cookie(second)
 if encoding:
 return encoding, [first, second]

 return default, [first, second]


def open(filename):
 """Open a file in read only mode using the encoding detected by
 detect_encoding().
 """
 buffer = _builtin_open(filename, 'rb')
 try:
 encoding, lines = detect_encoding(buffer.readline)
 buffer.seek(0)
 text = TextIOWrapper(buffer, encoding, line_buffering=True)
 text.mode = 'r'
 return text
 except:
 buffer.close()
 raise


def tokenize(readline):
 """
 The tokenize() generator requires one argument, readline, which
 must be a callable object which provides the same interface as the
 readline() method of built-in file objects. Each call to the function
 should return one line of input as bytes. Alternatively, readline
 can be a callable function terminating with StopIteration:
 readline = open(myfile, 'rb').__next__ # Example of alternate readline

 The generator produces 5-tuples with these members: the token type; the
 token string; a 2-tuple (srow, scol) of ints specifying the row and
 column where the token begins in the source; a 2-tuple (erow, ecol) of
 ints specifying the row and column where the token ends in the source;
 and the line on which the token was found. The line passed is the
 physical line.

 The first token sequence will always be an ENCODING token
 which tells you which encoding was used to decode the bytes stream.
 """
 encoding, consumed = detect_encoding(readline)
 empty = _itertools.repeat(b"")
 rl_gen = _itertools.chain(consumed, iter(readline, b""), empty)
 return _tokenize(rl_gen.__next__, encoding)


def _tokenize(readline, encoding):
 lnum = parenlev = continued = 0
 numchars = '0123456789'
 contstr, needcont = '', 0
 contline = None
 indents = [0]

 if encoding is not None:
 if encoding == "utf-8-sig":
 # BOM will already have been stripped.
 encoding = "utf-8"
 yield TokenInfo(ENCODING, encoding, (0, 0), (0, 0), '')
 last_line = b''
 line = b''
 while True: # loop over lines in stream
 try:
 # We capture the value of the line variable here because
 # readline uses the empty string '' to signal end of input,
 # hence `line` itself will always be overwritten at the end
 # of this loop.
 last_line = line
 line = readline()
 except StopIteration:
 line = b''

 if encoding is not None:
 line = line.decode(encoding)
 lnum += 1
 pos, max = 0, len(line)

 if contstr: # continued string
 if not line:
 raise TokenError("EOF in multi-line string", strstart)
 endmatch = endprog.match(line)
 if endmatch:
 pos = end = endmatch.end(0)
 yield TokenInfo(STRING, contstr + line[:end],
 strstart, (lnum, end), contline + line)
 contstr, needcont = '', 0
 contline = None
 elif needcont and line[-2:] != '\\\n' and line[-3:] != '\\\r\n':
 yield TokenInfo(ERRORTOKEN, contstr + line,
 strstart, (lnum, len(line)), contline)
 contstr = ''
 contline = None
 continue
 else:
 contstr = contstr + line
 contline = contline + line
 continue

 elif parenlev == 0 and not continued: # new statement
 if not line: break
 column = 0
 while pos < max: # measure leading whitespace
 if line[pos] == ' ':
 column += 1
 elif line[pos] == '\t':
 column = (column//tabsize + 1)*tabsize
 elif line[pos] == '\f':
 column = 0
 else:
 break
 pos += 1
 if pos == max:
 break

 if line[pos] in '#\r\n': # skip comments or blank lines
 if line[pos] == '#':
 comment_token = line[pos:].rstrip('\r\n')
 yield TokenInfo(COMMENT, comment_token,
 (lnum, pos), (lnum, pos + len(comment_token)), line)
 pos += len(comment_token)

 yield TokenInfo(NL, line[pos:],
 (lnum, pos), (lnum, len(line)), line)
 continue

 if column > indents[-1]: # count indents or dedents
 indents.append(column)
 yield TokenInfo(INDENT, line[:pos], (lnum, 0), (lnum, pos), line)
 while column < indents[-1]:
 if column not in indents:
 raise IndentationError(
 "unindent does not match any outer indentation level",
 ("<tokenize>", lnum, pos, line))
 indents = indents[:-1]

 yield TokenInfo(DEDENT, '', (lnum, pos), (lnum, pos), line)

 else: # continued statement
 if not line:
 raise TokenError("EOF in multi-line statement", (lnum, 0))
 continued = 0

 while pos < max:
 pseudomatch = _compile(PseudoToken).match(line, pos)
 if pseudomatch: # scan for tokens
 start, end = pseudomatch.span(1)
 spos, epos, pos = (lnum, start), (lnum, end), end
 if start == end:
 continue
 token, initial = line[start:end], line[start]

 if (initial in numchars or # ordinary number
 (initial == '.' and token != '.' and token != '...')):
 yield TokenInfo(NUMBER, token, spos, epos, line)
 elif initial in '\r\n':
 if parenlev > 0:
 yield TokenInfo(NL, token, spos, epos, line)
 else:
 yield TokenInfo(NEWLINE, token, spos, epos, line)

 elif initial == '#':
 assert not token.endswith("\n")
 yield TokenInfo(COMMENT, token, spos, epos, line)

 elif token in triple_quoted:
 endprog = _compile(endpats[token])
 endmatch = endprog.match(line, pos)
 if endmatch: # all on one line
 pos = endmatch.end(0)
 token = line[start:pos]
 yield TokenInfo(STRING, token, spos, (lnum, pos), line)
 else:
 strstart = (lnum, start) # multiple lines
 contstr = line[start:]
 contline = line
 break

 # Check up to the first 3 chars of the token to see if
 # they're in the single_quoted set. If so, they start
 # a string.
 # We're using the first 3, because we're looking for
 # "rb'" (for example) at the start of the token. If
 # we switch to longer prefixes, this needs to be
 # adjusted.
 # Note that initial == token[:1].
 # Also note that single quote checking must come after
 # triple quote checking (above).
 elif (initial in single_quoted or
 token[:2] in single_quoted or
 token[:3] in single_quoted):
 if token[-1] == '\n': # continued string
 strstart = (lnum, start)
 # Again, using the first 3 chars of the
 # token. This is looking for the matching end
 # regex for the correct type of quote
 # character. So it's really looking for
 # endpats["'"] or endpats['"'], by trying to
 # skip string prefix characters, if any.
 endprog = _compile(endpats.get(initial) or
 endpats.get(token[1]) or
 endpats.get(token[2]))
 contstr, needcont = line[start:], 1
 contline = line
 break
 else: # ordinary string
 yield TokenInfo(STRING, token, spos, epos, line)

 elif initial.isidentifier(): # ordinary name
 yield TokenInfo(NAME, token, spos, epos, line)
 elif initial == '\\': # continued stmt
 continued = 1
 else:
 if initial in '([{':
 parenlev += 1
 elif initial in ')]}':
 parenlev -= 1
 yield TokenInfo(OP, token, spos, epos, line)
 else:
 yield TokenInfo(ERRORTOKEN, line[pos],
 (lnum, pos), (lnum, pos+1), line)
 pos += 1

 # Add an implicit NEWLINE if the input doesn't end in one
 if last_line and last_line[-1] not in '\r\n':
 yield TokenInfo(NEWLINE, '', (lnum - 1, len(last_line)), (lnum - 1, len(last_line) + 1), '')
 for indent in indents[1:]: # pop remaining indent levels
 yield TokenInfo(DEDENT, '', (lnum, 0), (lnum, 0), '')
 yield TokenInfo(ENDMARKER, '', (lnum, 0), (lnum, 0), '')


def generate_tokens(readline):
 """Tokenize a source reading Python code as unicode strings.

 This has the same API as tokenize(), except that it expects the *readline*
 callable to return str objects instead of bytes.
 """
 return _tokenize(readline, None)

def main():
 import argparse

 # Helper error handling routines
 def perror(message):
 sys.stderr.write(message)
 sys.stderr.write('\n')

 def error(message, filename=None, location=None):
 if location:
 args = (filename,) + location + (message,)
 perror("%s:%d:%d: error: %s" % args)
 elif filename:
 perror("%s: error: %s" % (filename, message))
 else:
 perror("error: %s" % message)
 sys.exit(1)

 # Parse the arguments and options
 parser = argparse.ArgumentParser(prog='python -m tokenize')
 parser.add_argument(dest='filename', nargs='?',
 metavar='filename.py',
 help='the file to tokenize; defaults to stdin')
 parser.add_argument('-e', '--exact', dest='exact', action='store_true',
 help='display token names using the exact type')
 args = parser.parse_args()

 try:
 # Tokenize the input
 if args.filename:
 filename = args.filename
 with _builtin_open(filename, 'rb') as f:
 tokens = list(tokenize(f.readline))
 else:
 filename = "<stdin>"
 tokens = _tokenize(sys.stdin.readline, None)

 # Output the tokenization
 for token in tokens:
 token_type = token.type
 if args.exact:
 token_type = token.exact_type
 token_range = "%d,%d-%d,%d:" % (token.start + token.end)
 print("%-20s%-15s%-15r" %
 (token_range, tok_name[token_type], token.string))
 except IndentationError as err:
 line, column = err.args[1][1:3]
 error(err.args[0], filename, (line, column))
 except TokenError as err:
 line, column = err.args[1]
 error(err.args[0], filename, (line, column))
 except SyntaxError as err:
 error(err, filename)
 except OSError as err:
 error(err)
 except KeyboardInterrupt:
 print("interrupted\n")
 except Exception as err:
 perror("unexpected error: %s" % err)
 raise

if __name__ == "__main__":
 main()