mirror of https://github.com/python/cpython
564 lines
21 KiB
Python
564 lines
21 KiB
Python
# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006 Python Software Foundation.
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# All rights reserved.
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"""Tokenization help for Python programs.
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generate_tokens(readline) is a generator that breaks a stream of
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text into Python tokens. It accepts a readline-like method which is called
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repeatedly to get the next line of input (or "" for EOF). It generates
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5-tuples with these members:
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the token type (see token.py)
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the token (a string)
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the starting (row, column) indices of the token (a 2-tuple of ints)
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the ending (row, column) indices of the token (a 2-tuple of ints)
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the original line (string)
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It is designed to match the working of the Python tokenizer exactly, except
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that it produces COMMENT tokens for comments and gives type OP for all
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operators
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Older entry points
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tokenize_loop(readline, tokeneater)
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tokenize(readline, tokeneater=printtoken)
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are the same, except instead of generating tokens, tokeneater is a callback
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function to which the 5 fields described above are passed as 5 arguments,
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each time a new token is found."""
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__author__ = 'Ka-Ping Yee <ping@lfw.org>'
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__credits__ = \
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'GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, Skip Montanaro'
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import string, re
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from codecs import BOM_UTF8, lookup
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from lib2to3.pgen2.token import *
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from . import token
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__all__ = [x for x in dir(token) if x[0] != '_'] + ["tokenize",
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"generate_tokens", "untokenize"]
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del token
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try:
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bytes
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except NameError:
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# Support bytes type in Python <= 2.5, so 2to3 turns itself into
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# valid Python 3 code.
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bytes = str
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def group(*choices): return '(' + '|'.join(choices) + ')'
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def any(*choices): return group(*choices) + '*'
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def maybe(*choices): return group(*choices) + '?'
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def _combinations(*l):
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return set(
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x + y for x in l for y in l + ("",) if x.casefold() != y.casefold()
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)
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Whitespace = r'[ \f\t]*'
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Comment = r'#[^\r\n]*'
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Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment)
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Name = r'\w+'
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Binnumber = r'0[bB]_?[01]+(?:_[01]+)*'
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Hexnumber = r'0[xX]_?[\da-fA-F]+(?:_[\da-fA-F]+)*[lL]?'
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Octnumber = r'0[oO]?_?[0-7]+(?:_[0-7]+)*[lL]?'
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Decnumber = group(r'[1-9]\d*(?:_\d+)*[lL]?', '0[lL]?')
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Intnumber = group(Binnumber, Hexnumber, Octnumber, Decnumber)
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Exponent = r'[eE][-+]?\d+(?:_\d+)*'
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Pointfloat = group(r'\d+(?:_\d+)*\.(?:\d+(?:_\d+)*)?', r'\.\d+(?:_\d+)*') + maybe(Exponent)
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Expfloat = r'\d+(?:_\d+)*' + Exponent
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Floatnumber = group(Pointfloat, Expfloat)
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Imagnumber = group(r'\d+(?:_\d+)*[jJ]', Floatnumber + r'[jJ]')
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Number = group(Imagnumber, Floatnumber, Intnumber)
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# Tail end of ' string.
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Single = r"[^'\\]*(?:\\.[^'\\]*)*'"
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# Tail end of " string.
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Double = r'[^"\\]*(?:\\.[^"\\]*)*"'
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# Tail end of ''' string.
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Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''"
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# Tail end of """ string.
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Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""'
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_litprefix = r"(?:[uUrRbBfF]|[rR][fFbB]|[fFbBuU][rR])?"
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Triple = group(_litprefix + "'''", _litprefix + '"""')
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# Single-line ' or " string.
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String = group(_litprefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*'",
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_litprefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*"')
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# Because of leftmost-then-longest match semantics, be sure to put the
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# longest operators first (e.g., if = came before ==, == would get
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# recognized as two instances of =).
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Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"<>", r"!=",
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r"//=?", r"->",
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r"[+\-*/%&@|^=<>]=?",
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r"~")
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Bracket = '[][(){}]'
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Special = group(r'\r?\n', r':=', r'[:;.,`@]')
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Funny = group(Operator, Bracket, Special)
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PlainToken = group(Number, Funny, String, Name)
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Token = Ignore + PlainToken
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# First (or only) line of ' or " string.
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ContStr = group(_litprefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
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group("'", r'\\\r?\n'),
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_litprefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
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group('"', r'\\\r?\n'))
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PseudoExtras = group(r'\\\r?\n', Comment, Triple)
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PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)
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tokenprog, pseudoprog, single3prog, double3prog = map(
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re.compile, (Token, PseudoToken, Single3, Double3))
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_strprefixes = (
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_combinations('r', 'R', 'f', 'F') |
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_combinations('r', 'R', 'b', 'B') |
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{'u', 'U', 'ur', 'uR', 'Ur', 'UR'}
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)
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endprogs = {"'": re.compile(Single), '"': re.compile(Double),
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"'''": single3prog, '"""': double3prog,
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**{f"{prefix}'''": single3prog for prefix in _strprefixes},
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**{f'{prefix}"""': double3prog for prefix in _strprefixes},
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**{prefix: None for prefix in _strprefixes}}
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triple_quoted = (
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{"'''", '"""'} |
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{f"{prefix}'''" for prefix in _strprefixes} |
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{f'{prefix}"""' for prefix in _strprefixes}
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)
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single_quoted = (
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{"'", '"'} |
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{f"{prefix}'" for prefix in _strprefixes} |
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{f'{prefix}"' for prefix in _strprefixes}
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)
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tabsize = 8
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class TokenError(Exception): pass
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class StopTokenizing(Exception): pass
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def printtoken(type, token, xxx_todo_changeme, xxx_todo_changeme1, line): # for testing
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(srow, scol) = xxx_todo_changeme
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(erow, ecol) = xxx_todo_changeme1
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print("%d,%d-%d,%d:\t%s\t%s" % \
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(srow, scol, erow, ecol, tok_name[type], repr(token)))
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def tokenize(readline, tokeneater=printtoken):
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"""
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The tokenize() function accepts two parameters: one representing the
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input stream, and one providing an output mechanism for tokenize().
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The first parameter, readline, must be a callable object which provides
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the same interface as the readline() method of built-in file objects.
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Each call to the function should return one line of input as a string.
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The second parameter, tokeneater, must also be a callable object. It is
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called once for each token, with five arguments, corresponding to the
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tuples generated by generate_tokens().
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"""
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try:
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tokenize_loop(readline, tokeneater)
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except StopTokenizing:
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pass
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# backwards compatible interface
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def tokenize_loop(readline, tokeneater):
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for token_info in generate_tokens(readline):
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tokeneater(*token_info)
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class Untokenizer:
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def __init__(self):
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self.tokens = []
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self.prev_row = 1
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self.prev_col = 0
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def add_whitespace(self, start):
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row, col = start
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assert row <= self.prev_row
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col_offset = col - self.prev_col
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if col_offset:
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self.tokens.append(" " * col_offset)
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def untokenize(self, iterable):
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for t in iterable:
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if len(t) == 2:
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self.compat(t, iterable)
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break
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tok_type, token, start, end, line = t
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self.add_whitespace(start)
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self.tokens.append(token)
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self.prev_row, self.prev_col = end
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if tok_type in (NEWLINE, NL):
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self.prev_row += 1
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self.prev_col = 0
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return "".join(self.tokens)
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def compat(self, token, iterable):
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startline = False
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indents = []
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toks_append = self.tokens.append
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toknum, tokval = token
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if toknum in (NAME, NUMBER):
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tokval += ' '
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if toknum in (NEWLINE, NL):
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startline = True
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for tok in iterable:
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toknum, tokval = tok[:2]
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if toknum in (NAME, NUMBER, ASYNC, AWAIT):
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tokval += ' '
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if toknum == INDENT:
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indents.append(tokval)
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continue
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elif toknum == DEDENT:
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indents.pop()
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continue
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elif toknum in (NEWLINE, NL):
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startline = True
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elif startline and indents:
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toks_append(indents[-1])
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startline = False
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toks_append(tokval)
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cookie_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)', re.ASCII)
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blank_re = re.compile(br'^[ \t\f]*(?:[#\r\n]|$)', re.ASCII)
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def _get_normal_name(orig_enc):
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"""Imitates get_normal_name in tokenizer.c."""
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# Only care about the first 12 characters.
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enc = orig_enc[:12].lower().replace("_", "-")
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if enc == "utf-8" or enc.startswith("utf-8-"):
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return "utf-8"
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if enc in ("latin-1", "iso-8859-1", "iso-latin-1") or \
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enc.startswith(("latin-1-", "iso-8859-1-", "iso-latin-1-")):
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return "iso-8859-1"
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return orig_enc
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def detect_encoding(readline):
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"""
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The detect_encoding() function is used to detect the encoding that should
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be used to decode a Python source file. It requires one argument, readline,
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in the same way as the tokenize() generator.
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It will call readline a maximum of twice, and return the encoding used
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(as a string) and a list of any lines (left as bytes) it has read
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in.
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It detects the encoding from the presence of a utf-8 bom or an encoding
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cookie as specified in pep-0263. If both a bom and a cookie are present, but
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disagree, a SyntaxError will be raised. If the encoding cookie is an invalid
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charset, raise a SyntaxError. Note that if a utf-8 bom is found,
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'utf-8-sig' is returned.
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If no encoding is specified, then the default of 'utf-8' will be returned.
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"""
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bom_found = False
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encoding = None
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default = 'utf-8'
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def read_or_stop():
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try:
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return readline()
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except StopIteration:
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return bytes()
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def find_cookie(line):
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try:
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line_string = line.decode('ascii')
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except UnicodeDecodeError:
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return None
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match = cookie_re.match(line_string)
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if not match:
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return None
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encoding = _get_normal_name(match.group(1))
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try:
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codec = lookup(encoding)
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except LookupError:
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# This behaviour mimics the Python interpreter
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raise SyntaxError("unknown encoding: " + encoding)
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if bom_found:
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if codec.name != 'utf-8':
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# This behaviour mimics the Python interpreter
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raise SyntaxError('encoding problem: utf-8')
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encoding += '-sig'
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return encoding
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first = read_or_stop()
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if first.startswith(BOM_UTF8):
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bom_found = True
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first = first[3:]
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default = 'utf-8-sig'
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if not first:
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return default, []
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encoding = find_cookie(first)
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if encoding:
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return encoding, [first]
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if not blank_re.match(first):
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return default, [first]
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second = read_or_stop()
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if not second:
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return default, [first]
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encoding = find_cookie(second)
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if encoding:
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return encoding, [first, second]
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return default, [first, second]
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def untokenize(iterable):
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"""Transform tokens back into Python source code.
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Each element returned by the iterable must be a token sequence
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with at least two elements, a token number and token value. If
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only two tokens are passed, the resulting output is poor.
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Round-trip invariant for full input:
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Untokenized source will match input source exactly
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Round-trip invariant for limited input:
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# Output text will tokenize the back to the input
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t1 = [tok[:2] for tok in generate_tokens(f.readline)]
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newcode = untokenize(t1)
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readline = iter(newcode.splitlines(1)).next
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t2 = [tok[:2] for tokin generate_tokens(readline)]
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assert t1 == t2
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"""
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ut = Untokenizer()
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return ut.untokenize(iterable)
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def generate_tokens(readline):
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"""
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The generate_tokens() generator requires one argument, readline, which
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must be a callable object which provides the same interface as the
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readline() method of built-in file objects. Each call to the function
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should return one line of input as a string. Alternately, readline
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can be a callable function terminating with StopIteration:
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readline = open(myfile).next # Example of alternate readline
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The generator produces 5-tuples with these members: the token type; the
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token string; a 2-tuple (srow, scol) of ints specifying the row and
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column where the token begins in the source; a 2-tuple (erow, ecol) of
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ints specifying the row and column where the token ends in the source;
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and the line on which the token was found. The line passed is the
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physical line.
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"""
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lnum = parenlev = continued = 0
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contstr, needcont = '', 0
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contline = None
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indents = [0]
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# 'stashed' and 'async_*' are used for async/await parsing
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stashed = None
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async_def = False
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async_def_indent = 0
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async_def_nl = False
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while 1: # loop over lines in stream
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try:
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line = readline()
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except StopIteration:
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line = ''
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lnum = lnum + 1
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pos, max = 0, len(line)
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if contstr: # continued string
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if not line:
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raise TokenError("EOF in multi-line string", strstart)
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endmatch = endprog.match(line)
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if endmatch:
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pos = end = endmatch.end(0)
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yield (STRING, contstr + line[:end],
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strstart, (lnum, end), contline + line)
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contstr, needcont = '', 0
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contline = None
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elif needcont and line[-2:] != '\\\n' and line[-3:] != '\\\r\n':
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yield (ERRORTOKEN, contstr + line,
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strstart, (lnum, len(line)), contline)
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contstr = ''
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contline = None
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continue
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else:
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contstr = contstr + line
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contline = contline + line
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continue
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elif parenlev == 0 and not continued: # new statement
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if not line: break
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column = 0
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while pos < max: # measure leading whitespace
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if line[pos] == ' ': column = column + 1
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elif line[pos] == '\t': column = (column//tabsize + 1)*tabsize
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elif line[pos] == '\f': column = 0
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else: break
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pos = pos + 1
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if pos == max: break
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if stashed:
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yield stashed
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stashed = None
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if line[pos] in '#\r\n': # skip comments or blank lines
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if line[pos] == '#':
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comment_token = line[pos:].rstrip('\r\n')
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nl_pos = pos + len(comment_token)
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yield (COMMENT, comment_token,
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(lnum, pos), (lnum, pos + len(comment_token)), line)
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yield (NL, line[nl_pos:],
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(lnum, nl_pos), (lnum, len(line)), line)
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else:
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yield ((NL, COMMENT)[line[pos] == '#'], line[pos:],
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(lnum, pos), (lnum, len(line)), line)
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continue
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if column > indents[-1]: # count indents or dedents
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indents.append(column)
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yield (INDENT, line[:pos], (lnum, 0), (lnum, pos), line)
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while column < indents[-1]:
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if column not in indents:
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raise IndentationError(
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"unindent does not match any outer indentation level",
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("<tokenize>", lnum, pos, line))
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indents = indents[:-1]
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if async_def and async_def_indent >= indents[-1]:
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async_def = False
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async_def_nl = False
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async_def_indent = 0
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yield (DEDENT, '', (lnum, pos), (lnum, pos), line)
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if async_def and async_def_nl and async_def_indent >= indents[-1]:
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async_def = False
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async_def_nl = False
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async_def_indent = 0
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else: # continued statement
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if not line:
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raise TokenError("EOF in multi-line statement", (lnum, 0))
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continued = 0
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while pos < max:
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pseudomatch = pseudoprog.match(line, pos)
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if pseudomatch: # scan for tokens
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start, end = pseudomatch.span(1)
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spos, epos, pos = (lnum, start), (lnum, end), end
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token, initial = line[start:end], line[start]
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if initial in string.digits or \
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(initial == '.' and token != '.'): # ordinary number
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yield (NUMBER, token, spos, epos, line)
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elif initial in '\r\n':
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newline = NEWLINE
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if parenlev > 0:
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newline = NL
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elif async_def:
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async_def_nl = True
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if stashed:
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yield stashed
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stashed = None
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yield (newline, token, spos, epos, line)
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elif initial == '#':
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assert not token.endswith("\n")
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if stashed:
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yield stashed
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stashed = None
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yield (COMMENT, token, spos, epos, line)
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elif token in triple_quoted:
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endprog = endprogs[token]
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endmatch = endprog.match(line, pos)
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if endmatch: # all on one line
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pos = endmatch.end(0)
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token = line[start:pos]
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if stashed:
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yield stashed
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stashed = None
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yield (STRING, token, spos, (lnum, pos), line)
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else:
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strstart = (lnum, start) # multiple lines
|
|
contstr = line[start:]
|
|
contline = line
|
|
break
|
|
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)
|
|
endprog = (endprogs[initial] or endprogs[token[1]] or
|
|
endprogs[token[2]])
|
|
contstr, needcont = line[start:], 1
|
|
contline = line
|
|
break
|
|
else: # ordinary string
|
|
if stashed:
|
|
yield stashed
|
|
stashed = None
|
|
yield (STRING, token, spos, epos, line)
|
|
elif initial.isidentifier(): # ordinary name
|
|
if token in ('async', 'await'):
|
|
if async_def:
|
|
yield (ASYNC if token == 'async' else AWAIT,
|
|
token, spos, epos, line)
|
|
continue
|
|
|
|
tok = (NAME, token, spos, epos, line)
|
|
if token == 'async' and not stashed:
|
|
stashed = tok
|
|
continue
|
|
|
|
if token == 'def':
|
|
if (stashed
|
|
and stashed[0] == NAME
|
|
and stashed[1] == 'async'):
|
|
|
|
async_def = True
|
|
async_def_indent = indents[-1]
|
|
|
|
yield (ASYNC, stashed[1],
|
|
stashed[2], stashed[3],
|
|
stashed[4])
|
|
stashed = None
|
|
|
|
if stashed:
|
|
yield stashed
|
|
stashed = None
|
|
|
|
yield tok
|
|
elif initial == '\\': # continued stmt
|
|
# This yield is new; needed for better idempotency:
|
|
if stashed:
|
|
yield stashed
|
|
stashed = None
|
|
yield (NL, token, spos, (lnum, pos), line)
|
|
continued = 1
|
|
else:
|
|
if initial in '([{': parenlev = parenlev + 1
|
|
elif initial in ')]}': parenlev = parenlev - 1
|
|
if stashed:
|
|
yield stashed
|
|
stashed = None
|
|
yield (OP, token, spos, epos, line)
|
|
else:
|
|
yield (ERRORTOKEN, line[pos],
|
|
(lnum, pos), (lnum, pos+1), line)
|
|
pos = pos + 1
|
|
|
|
if stashed:
|
|
yield stashed
|
|
stashed = None
|
|
|
|
for indent in indents[1:]: # pop remaining indent levels
|
|
yield (DEDENT, '', (lnum, 0), (lnum, 0), '')
|
|
yield (ENDMARKER, '', (lnum, 0), (lnum, 0), '')
|
|
|
|
if __name__ == '__main__': # testing
|
|
import sys
|
|
if len(sys.argv) > 1: tokenize(open(sys.argv[1]).readline)
|
|
else: tokenize(sys.stdin.readline)
|