Patchwork D5043: hgdemandimport: vendor CPython 3.7 tokenizer modules

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Submitter phabricator
Date Oct. 13, 2018, 7:28 a.m.
Message ID <differential-rev-PHID-DREV-yotnamln5rozafzf4bi7-req@phab.mercurial-scm.org>
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Permalink /patch/35830/
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phabricator - Oct. 13, 2018, 7:28 a.m.
indygreg created this revision.
Herald added subscribers: mercurial-devel, mjpieters.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  I have an evil plan to leverage the Python 3 tokenizer on Python 2.7.
  
  The added files are Lib/token.py and Lib/tokenize.py from cpython's
  Git repository at commit d4ed8809ddfaa23fe5edf2987c03afc32f5576c0. This
  commit corresponds to the current development tip of the 3.7 branch.
  The only commit since the 3.7.0 tag is
  ab75d9e4244ee24bc96ea9d52362899e3bf365a2, which appears to contain a minor
  fix to make the Python code more consistent with the C implementation.
  
  The files are added without modifications. Future commits will tidy
  things up a bit.
  
  Because the files are third party, I've added them to static analysis
  exclusion lists.
  
  test-check-py3-compat.t and test-check-module-imports.t currently fail.
  I'll deal with that in a subsequent commit.
  
  1. no-check-commit style violations galore

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D5043

AFFECTED FILES
  hgdemandimport/py3token.py
  hgdemandimport/py3tokenize.py
  tests/test-check-code.t
  tests/test-check-pyflakes.t
  tests/test-check-pylint.t

CHANGE DETAILS




To: indygreg, #hg-reviewers
Cc: mjpieters, mercurial-devel

Patch

diff --git a/tests/test-check-pylint.t b/tests/test-check-pylint.t
--- a/tests/test-check-pylint.t
+++ b/tests/test-check-pylint.t
@@ -13,7 +13,7 @@ 
   $ pylint --rcfile=$TESTTMP/fakerc --disable=all \
   >   --enable=W0102,C0321 \
   >   --reports=no \
-  >   --ignore=thirdparty \
+  >   --ignore=thirdparty,py3token.py,py3tokenize.py \
   >   mercurial hgdemandimport hgext hgext3rd | sed 's/\r$//'
   Using config file *fakerc (glob) (?)
    (?)
diff --git a/tests/test-check-pyflakes.t b/tests/test-check-pyflakes.t
--- a/tests/test-check-pyflakes.t
+++ b/tests/test-check-pyflakes.t
@@ -14,6 +14,8 @@ 
   $ cd "`dirname "$TESTDIR"`"
 
   $ testrepohg locate 'set:**.py or grep("^#!.*python")' \
+  > -X hgdemandimport/py3token.py \
+  > -X hgdemandimport/py3tokenize.py \
   > -X hgext/fsmonitor/pywatchman \
   > -X mercurial/pycompat.py -X contrib/python-zstandard \
   > -X mercurial/thirdparty/cbor \
diff --git a/tests/test-check-code.t b/tests/test-check-code.t
--- a/tests/test-check-code.t
+++ b/tests/test-check-code.t
@@ -9,6 +9,8 @@ 
 
   $ testrepohg locate \
   > -X contrib/python-zstandard \
+  > -X hgdemandimport/py3token.py \
+  > -X hgdemandimport/py3tokenize.py \
   > -X hgext/fsmonitor/pywatchman \
   > -X mercurial/thirdparty \
   > | sed 's-\\-/-g' | "$check_code" --warnings --per-file=0 - || false
diff --git a/hgdemandimport/py3tokenize.py b/hgdemandimport/py3tokenize.py
new file mode 100644
--- /dev/null
+++ b/hgdemandimport/py3tokenize.py
@@ -0,0 +1,736 @@ 
+"""Tokenization help for Python programs.
+
+tokenize(readline) is a generator that breaks a stream of bytes into
+Python tokens.  It decodes the bytes according to PEP-0263 for
+determining source file encoding.
+
+It accepts a readline-like method which is called repeatedly to get the
+next line of input (or b"" for EOF).  It generates 5-tuples with these
+members:
+
+    the token type (see token.py)
+    the token (a string)
+    the starting (row, column) indices of the token (a 2-tuple of ints)
+    the ending (row, column) indices of the token (a 2-tuple of ints)
+    the original line (string)
+
+It is designed to match the working of the Python tokenizer exactly, except
+that it produces COMMENT tokens for comments and gives type OP for all
+operators.  Additionally, all token lists start with an ENCODING token
+which tells you which encoding was used to decode the bytes stream.
+"""
+
+__author__ = 'Ka-Ping Yee <ping@lfw.org>'
+__credits__ = ('GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, '
+               'Skip Montanaro, Raymond Hettinger, Trent Nelson, '
+               'Michael Foord')
+from builtins import open as _builtin_open
+from codecs import lookup, BOM_UTF8
+import collections
+from io import TextIOWrapper
+from itertools import chain
+import itertools as _itertools
+import re
+import sys
+from token import *
+
+cookie_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)', re.ASCII)
+blank_re = re.compile(br'^[ \t\f]*(?:[#\r\n]|$)', re.ASCII)
+
+import token
+__all__ = token.__all__ + ["tokenize", "detect_encoding",
+                           "untokenize", "TokenInfo"]
+del token
+
+EXACT_TOKEN_TYPES = {
+    '(':   LPAR,
+    ')':   RPAR,
+    '[':   LSQB,
+    ']':   RSQB,
+    ':':   COLON,
+    ',':   COMMA,
+    ';':   SEMI,
+    '+':   PLUS,
+    '-':   MINUS,
+    '*':   STAR,
+    '/':   SLASH,
+    '|':   VBAR,
+    '&':   AMPER,
+    '<':   LESS,
+    '>':   GREATER,
+    '=':   EQUAL,
+    '.':   DOT,
+    '%':   PERCENT,
+    '{':   LBRACE,
+    '}':   RBRACE,
+    '==':  EQEQUAL,
+    '!=':  NOTEQUAL,
+    '<=':  LESSEQUAL,
+    '>=':  GREATEREQUAL,
+    '~':   TILDE,
+    '^':   CIRCUMFLEX,
+    '<<':  LEFTSHIFT,
+    '>>':  RIGHTSHIFT,
+    '**':  DOUBLESTAR,
+    '+=':  PLUSEQUAL,
+    '-=':  MINEQUAL,
+    '*=':  STAREQUAL,
+    '/=':  SLASHEQUAL,
+    '%=':  PERCENTEQUAL,
+    '&=':  AMPEREQUAL,
+    '|=':  VBAREQUAL,
+    '^=':  CIRCUMFLEXEQUAL,
+    '<<=': LEFTSHIFTEQUAL,
+    '>>=': RIGHTSHIFTEQUAL,
+    '**=': DOUBLESTAREQUAL,
+    '//':  DOUBLESLASH,
+    '//=': DOUBLESLASHEQUAL,
+    '...': ELLIPSIS,
+    '->':  RARROW,
+    '@':   AT,
+    '@=':  ATEQUAL,
+}
+
+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 permuations (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"\\]*)*"')
+
+# Because of leftmost-then-longest match semantics, be sure to put the
+# longest operators first (e.g., if = came before ==, == would get
+# recognized as two instances of =).
+Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"!=",
+                 r"//=?", r"->",
+                 r"[+\-*/%&@|^=<>]=?",
+                 r"~")
+
+Bracket = '[][(){}]'
+Special = group(r'\r?\n', r'\.\.\.', r'[:;.,@]')
+Funny = group(Operator, Bracket, 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 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
+    logical line; continuation lines are included.
+
+    The first token sequence will always be an ENCODING token
+    which tells you which encoding was used to decode the bytes stream.
+    """
+    # This import is here to avoid problems when the itertools module is not
+    # built yet and tokenize is imported.
+    from itertools import chain, repeat
+    encoding, consumed = detect_encoding(readline)
+    rl_gen = iter(readline, b"")
+    empty = repeat(b"")
+    return _tokenize(chain(consumed, rl_gen, empty).__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), '')
+
+
+# An undocumented, backwards compatible, API for all the places in the standard
+# library that expect to be able to use tokenize with strings
+def generate_tokens(readline):
+    return _tokenize(readline, None)
+
+def main():
+    import argparse
+
+    # Helper error handling routines
+    def perror(message):
+        print(message, file=sys.stderr)
+
+    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()
diff --git a/hgdemandimport/py3token.py b/hgdemandimport/py3token.py
new file mode 100644
--- /dev/null
+++ b/hgdemandimport/py3token.py
@@ -0,0 +1,160 @@ 
+"""Token constants (from "token.h")."""
+
+__all__ = ['tok_name', 'ISTERMINAL', 'ISNONTERMINAL', 'ISEOF']
+
+#  This file is automatically generated; please don't muck it up!
+#
+#  To update the symbols in this file, 'cd' to the top directory of
+#  the python source tree after building the interpreter and run:
+#
+#    ./python Lib/token.py
+
+#--start constants--
+ENDMARKER = 0
+NAME = 1
+NUMBER = 2
+STRING = 3
+NEWLINE = 4
+INDENT = 5
+DEDENT = 6
+LPAR = 7
+RPAR = 8
+LSQB = 9
+RSQB = 10
+COLON = 11
+COMMA = 12
+SEMI = 13
+PLUS = 14
+MINUS = 15
+STAR = 16
+SLASH = 17
+VBAR = 18
+AMPER = 19
+LESS = 20
+GREATER = 21
+EQUAL = 22
+DOT = 23
+PERCENT = 24
+LBRACE = 25
+RBRACE = 26
+EQEQUAL = 27
+NOTEQUAL = 28
+LESSEQUAL = 29
+GREATEREQUAL = 30
+TILDE = 31
+CIRCUMFLEX = 32
+LEFTSHIFT = 33
+RIGHTSHIFT = 34
+DOUBLESTAR = 35
+PLUSEQUAL = 36
+MINEQUAL = 37
+STAREQUAL = 38
+SLASHEQUAL = 39
+PERCENTEQUAL = 40
+AMPEREQUAL = 41
+VBAREQUAL = 42
+CIRCUMFLEXEQUAL = 43
+LEFTSHIFTEQUAL = 44
+RIGHTSHIFTEQUAL = 45
+DOUBLESTAREQUAL = 46
+DOUBLESLASH = 47
+DOUBLESLASHEQUAL = 48
+AT = 49
+ATEQUAL = 50
+RARROW = 51
+ELLIPSIS = 52
+# Don't forget to update the table _PyParser_TokenNames in tokenizer.c!
+OP = 53
+ERRORTOKEN = 54
+# These aren't used by the C tokenizer but are needed for tokenize.py
+COMMENT = 55
+NL = 56
+ENCODING = 57
+N_TOKENS = 58
+# Special definitions for cooperation with parser
+NT_OFFSET = 256
+#--end constants--
+
+tok_name = {value: name
+            for name, value in globals().items()
+            if isinstance(value, int) and not name.startswith('_')}
+__all__.extend(tok_name.values())
+
+def ISTERMINAL(x):
+    return x < NT_OFFSET
+
+def ISNONTERMINAL(x):
+    return x >= NT_OFFSET
+
+def ISEOF(x):
+    return x == ENDMARKER
+
+
+def _main():
+    import re
+    import sys
+    args = sys.argv[1:]
+    inFileName = args and args[0] or "Include/token.h"
+    outFileName = "Lib/token.py"
+    if len(args) > 1:
+        outFileName = args[1]
+    try:
+        fp = open(inFileName)
+    except OSError as err:
+        sys.stdout.write("I/O error: %s\n" % str(err))
+        sys.exit(1)
+    with fp:
+        lines = fp.read().split("\n")
+    prog = re.compile(
+        r"#define[ \t][ \t]*([A-Z0-9][A-Z0-9_]*)[ \t][ \t]*([0-9][0-9]*)",
+        re.IGNORECASE)
+    comment_regex = re.compile(
+        r"^\s*/\*\s*(.+?)\s*\*/\s*$",
+        re.IGNORECASE)
+
+    tokens = {}
+    prev_val = None
+    for line in lines:
+        match = prog.match(line)
+        if match:
+            name, val = match.group(1, 2)
+            val = int(val)
+            tokens[val] = {'token': name}          # reverse so we can sort them...
+            prev_val = val
+        else:
+            comment_match = comment_regex.match(line)
+            if comment_match and prev_val is not None:
+                comment = comment_match.group(1)
+                tokens[prev_val]['comment'] = comment
+    keys = sorted(tokens.keys())
+    # load the output skeleton from the target:
+    try:
+        fp = open(outFileName)
+    except OSError as err:
+        sys.stderr.write("I/O error: %s\n" % str(err))
+        sys.exit(2)
+    with fp:
+        format = fp.read().split("\n")
+    try:
+        start = format.index("#--start constants--") + 1
+        end = format.index("#--end constants--")
+    except ValueError:
+        sys.stderr.write("target does not contain format markers")
+        sys.exit(3)
+    lines = []
+    for key in keys:
+        lines.append("%s = %d" % (tokens[key]["token"], key))
+        if "comment" in tokens[key]:
+            lines.append("# %s" % tokens[key]["comment"])
+    format[start:end] = lines
+    try:
+        fp = open(outFileName, 'w')
+    except OSError as err:
+        sys.stderr.write("I/O error: %s\n" % str(err))
+        sys.exit(4)
+    with fp:
+        fp.write("\n".join(format))
+
+
+if __name__ == "__main__":
+    _main()