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Diffstat (limited to 'lib/python2.7/lib2to3/pgen2/tokenize.py')
| -rw-r--r-- | lib/python2.7/lib2to3/pgen2/tokenize.py | 502 |
1 files changed, 502 insertions, 0 deletions
diff --git a/lib/python2.7/lib2to3/pgen2/tokenize.py b/lib/python2.7/lib2to3/pgen2/tokenize.py new file mode 100644 index 0000000..8cae873 --- /dev/null +++ b/lib/python2.7/lib2to3/pgen2/tokenize.py @@ -0,0 +1,502 @@ +# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006 Python Software Foundation. +# All rights reserved. + +"""Tokenization help for Python programs. + +generate_tokens(readline) is a generator that breaks a stream of +text into Python tokens. It accepts a readline-like method which is called +repeatedly to get the next line of input (or "" 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 + +Older entry points + tokenize_loop(readline, tokeneater) + tokenize(readline, tokeneater=printtoken) +are the same, except instead of generating tokens, tokeneater is a callback +function to which the 5 fields described above are passed as 5 arguments, +each time a new token is found.""" + +__author__ = 'Ka-Ping Yee <ping@lfw.org>' +__credits__ = \ + 'GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, Skip Montanaro' + +import string, re +from codecs import BOM_UTF8, lookup +from lib2to3.pgen2.token import * + +from . import token +__all__ = [x for x in dir(token) if x[0] != '_'] + ["tokenize", + "generate_tokens", "untokenize"] +del token + +try: + bytes +except NameError: + # Support bytes type in Python <= 2.5, so 2to3 turns itself into + # valid Python 3 code. + bytes = str + +def group(*choices): return '(' + '|'.join(choices) + ')' +def any(*choices): return group(*choices) + '*' +def maybe(*choices): return group(*choices) + '?' + +Whitespace = r'[ \f\t]*' +Comment = r'#[^\r\n]*' +Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment) +Name = r'[a-zA-Z_]\w*' + +Binnumber = r'0[bB][01]*' +Hexnumber = r'0[xX][\da-fA-F]*[lL]?' +Octnumber = r'0[oO]?[0-7]*[lL]?' +Decnumber = r'[1-9]\d*[lL]?' +Intnumber = group(Binnumber, Hexnumber, Octnumber, Decnumber) +Exponent = r'[eE][-+]?\d+' +Pointfloat = group(r'\d+\.\d*', r'\.\d+') + maybe(Exponent) +Expfloat = r'\d+' + Exponent +Floatnumber = group(Pointfloat, Expfloat) +Imagnumber = group(r'\d+[jJ]', Floatnumber + r'[jJ]') +Number = group(Imagnumber, Floatnumber, Intnumber) + +# 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("[ubUB]?[rR]?'''", '[ubUB]?[rR]?"""') +# Single-line ' or " string. +String = group(r"[uU]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*'", + r'[uU]?[rR]?"[^\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"[+\-*/%&@|^=<>]=?", + r"~") + +Bracket = '[][(){}]' +Special = group(r'\r?\n', r'[:;.,`@]') +Funny = group(Operator, Bracket, Special) + +PlainToken = group(Number, Funny, String, Name) +Token = Ignore + PlainToken + +# First (or only) line of ' or " string. +ContStr = group(r"[uUbB]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" + + group("'", r'\\\r?\n'), + r'[uUbB]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' + + group('"', r'\\\r?\n')) +PseudoExtras = group(r'\\\r?\n', Comment, Triple) +PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name) + +tokenprog, pseudoprog, single3prog, double3prog = map( + re.compile, (Token, PseudoToken, Single3, Double3)) +endprogs = {"'": re.compile(Single), '"': re.compile(Double), + "'''": single3prog, '"""': double3prog, + "r'''": single3prog, 'r"""': double3prog, + "u'''": single3prog, 'u"""': double3prog, + "b'''": single3prog, 'b"""': double3prog, + "ur'''": single3prog, 'ur"""': double3prog, + "br'''": single3prog, 'br"""': double3prog, + "R'''": single3prog, 'R"""': double3prog, + "U'''": single3prog, 'U"""': double3prog, + "B'''": single3prog, 'B"""': double3prog, + "uR'''": single3prog, 'uR"""': double3prog, + "Ur'''": single3prog, 'Ur"""': double3prog, + "UR'''": single3prog, 'UR"""': double3prog, + "bR'''": single3prog, 'bR"""': double3prog, + "Br'''": single3prog, 'Br"""': double3prog, + "BR'''": single3prog, 'BR"""': double3prog, + 'r': None, 'R': None, + 'u': None, 'U': None, + 'b': None, 'B': None} + +triple_quoted = {} +for t in ("'''", '"""', + "r'''", 'r"""', "R'''", 'R"""', + "u'''", 'u"""', "U'''", 'U"""', + "b'''", 'b"""', "B'''", 'B"""', + "ur'''", 'ur"""', "Ur'''", 'Ur"""', + "uR'''", 'uR"""', "UR'''", 'UR"""', + "br'''", 'br"""', "Br'''", 'Br"""', + "bR'''", 'bR"""', "BR'''", 'BR"""',): + triple_quoted[t] = t +single_quoted = {} +for t in ("'", '"', + "r'", 'r"', "R'", 'R"', + "u'", 'u"', "U'", 'U"', + "b'", 'b"', "B'", 'B"', + "ur'", 'ur"', "Ur'", 'Ur"', + "uR'", 'uR"', "UR'", 'UR"', + "br'", 'br"', "Br'", 'Br"', + "bR'", 'bR"', "BR'", 'BR"', ): + single_quoted[t] = t + +tabsize = 8 + +class TokenError(Exception): pass + +class StopTokenizing(Exception): pass + +def printtoken(type, token, start, end, line): # for testing + (srow, scol) = start + (erow, ecol) = end + print "%d,%d-%d,%d:\t%s\t%s" % \ + (srow, scol, erow, ecol, tok_name[type], repr(token)) + +def tokenize(readline, tokeneater=printtoken): + """ + The tokenize() function accepts two parameters: one representing the + input stream, and one providing an output mechanism for tokenize(). + + The first parameter, readline, 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 a string. + + The second parameter, tokeneater, must also be a callable object. It is + called once for each token, with five arguments, corresponding to the + tuples generated by generate_tokens(). + """ + try: + tokenize_loop(readline, tokeneater) + except StopTokenizing: + pass + +# backwards compatible interface +def tokenize_loop(readline, tokeneater): + for token_info in generate_tokens(readline): + tokeneater(*token_info) + +class Untokenizer: + + def __init__(self): + self.tokens = [] + self.prev_row = 1 + self.prev_col = 0 + + def add_whitespace(self, start): + row, col = start + assert row <= self.prev_row + col_offset = col - self.prev_col + if col_offset: + self.tokens.append(" " * col_offset) + + def untokenize(self, iterable): + for t in iterable: + if len(t) == 2: + self.compat(t, iterable) + break + tok_type, token, start, end, line = t + 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): + startline = False + indents = [] + toks_append = self.tokens.append + toknum, tokval = token + if toknum in (NAME, NUMBER): + tokval += ' ' + if toknum in (NEWLINE, NL): + startline = True + for tok in iterable: + toknum, tokval = tok[:2] + + if toknum in (NAME, NUMBER): + tokval += ' ' + + 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) + +cookie_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)') +blank_re = re.compile(r'^[ \t\f]*(?:[#\r\n]|$)') + +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. + """ + bom_found = False + encoding = None + default = 'utf-8' + def read_or_stop(): + try: + return readline() + except StopIteration: + return bytes() + + def find_cookie(line): + try: + line_string = line.decode('ascii') + except UnicodeDecodeError: + return None + 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 + raise SyntaxError("unknown encoding: " + encoding) + + if bom_found: + if codec.name != 'utf-8': + # This behaviour mimics the Python interpreter + raise SyntaxError('encoding problem: utf-8') + 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 untokenize(iterable): + """Transform tokens back into Python source code. + + 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 intput: + # Output text will tokenize the back to the input + t1 = [tok[:2] for tok in generate_tokens(f.readline)] + newcode = untokenize(t1) + readline = iter(newcode.splitlines(1)).next + t2 = [tok[:2] for tokin generate_tokens(readline)] + assert t1 == t2 + """ + ut = Untokenizer() + return ut.untokenize(iterable) + +def generate_tokens(readline): + """ + The generate_tokens() 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 a string. Alternately, readline + can be a callable function terminating with StopIteration: + readline = open(myfile).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. + """ + lnum = parenlev = continued = 0 + namechars, numchars = string.ascii_letters + '_', '0123456789' + contstr, needcont = '', 0 + contline = None + indents = [0] + + while 1: # loop over lines in stream + try: + line = readline() + except StopIteration: + line = '' + lnum = 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 (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 (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 = column + 1 + elif line[pos] == '\t': column = (column//tabsize + 1)*tabsize + elif line[pos] == '\f': column = 0 + else: break + pos = 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') + nl_pos = pos + len(comment_token) + yield (COMMENT, comment_token, + (lnum, pos), (lnum, pos + len(comment_token)), line) + yield (NL, line[nl_pos:], + (lnum, nl_pos), (lnum, len(line)), line) + else: + yield ((NL, COMMENT)[line[pos] == '#'], line[pos:], + (lnum, pos), (lnum, len(line)), line) + continue + + if column > indents[-1]: # count indents or dedents + indents.append(column) + yield (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 (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 = pseudoprog.match(line, pos) + if pseudomatch: # scan for tokens + start, end = pseudomatch.span(1) + spos, epos, pos = (lnum, start), (lnum, end), end + token, initial = line[start:end], line[start] + + if initial in numchars or \ + (initial == '.' and token != '.'): # ordinary number + yield (NUMBER, token, spos, epos, line) + elif initial in '\r\n': + newline = NEWLINE + if parenlev > 0: + newline = NL + yield (newline, token, spos, epos, line) + elif initial == '#': + assert not token.endswith("\n") + yield (COMMENT, token, spos, epos, line) + elif token in triple_quoted: + endprog = endprogs[token] + endmatch = endprog.match(line, pos) + if endmatch: # all on one line + pos = endmatch.end(0) + token = line[start:pos] + yield (STRING, token, spos, (lnum, pos), line) + else: + 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 + yield (STRING, token, spos, epos, line) + elif initial in namechars: # ordinary name + yield (NAME, token, spos, epos, line) + elif initial == '\\': # continued stmt + # This yield is new; needed for better idempotency: + yield (NL, token, spos, (lnum, pos), line) + continued = 1 + else: + if initial in '([{': parenlev = parenlev + 1 + elif initial in ')]}': parenlev = parenlev - 1 + yield (OP, token, spos, epos, line) + else: + yield (ERRORTOKEN, line[pos], + (lnum, pos), (lnum, pos+1), line) + pos = pos + 1 + + 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) |