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286 lines
12 KiB
286 lines
12 KiB
"""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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from __future__ import generators |
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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 token import * |
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import token |
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__all__ = [x for x in dir(token) if x[0] != '_'] + ["COMMENT", "tokenize", "NL"] |
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del token |
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COMMENT = N_TOKENS |
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tok_name[COMMENT] = 'COMMENT' |
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NL = N_TOKENS + 1 |
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tok_name[NL] = 'NL' |
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N_TOKENS += 2 |
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def group(*choices): return '(' + '|'.join(choices) + ')' |
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def any(*choices): return apply(group, choices) + '*' |
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def maybe(*choices): return apply(group, choices) + '?' |
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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'[a-zA-Z_]\w*' |
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Hexnumber = r'0[xX][\da-fA-F]*[lL]?' |
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Octnumber = r'0[0-7]*[lL]?' |
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Decnumber = r'[1-9]\d*[lL]?' |
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Intnumber = group(Hexnumber, Octnumber, Decnumber) |
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Exponent = r'[eE][-+]?\d+' |
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Pointfloat = group(r'\d+\.\d*', r'\.\d+') + maybe(Exponent) |
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Expfloat = r'\d+' + Exponent |
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Floatnumber = group(Pointfloat, Expfloat) |
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Imagnumber = group(r'\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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Triple = group("[uU]?[rR]?'''", '[uU]?[rR]?"""') |
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# Single-line ' or " string. |
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String = group(r"[uU]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*'", |
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r'[uU]?[rR]?"[^\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"//=?", |
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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'[:;.,`]') |
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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(r"[uU]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" + |
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group("'", r'\\\r?\n'), |
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r'[uU]?[rR]?"[^\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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endprogs = {"'": re.compile(Single), '"': re.compile(Double), |
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"'''": single3prog, '"""': double3prog, |
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"r'''": single3prog, 'r"""': double3prog, |
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"u'''": single3prog, 'u"""': double3prog, |
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"ur'''": single3prog, 'ur"""': double3prog, |
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"R'''": single3prog, 'R"""': double3prog, |
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"U'''": single3prog, 'U"""': double3prog, |
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"uR'''": single3prog, 'uR"""': double3prog, |
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"Ur'''": single3prog, 'Ur"""': double3prog, |
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"UR'''": single3prog, 'UR"""': double3prog, |
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'r': None, 'R': None, 'u': None, 'U': None} |
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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, (srow, scol), (erow, ecol), line): # for testing |
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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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apply(tokeneater, token_info) |
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def generate_tokens(readline): |
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""" |
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The generate_tokens() generator requires one argment, 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. |
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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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logical line; continuation lines are included. |
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""" |
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lnum = parenlev = continued = 0 |
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namechars, numchars = string.ascii_letters + '_', '0123456789' |
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contstr, needcont = '', 0 |
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contline = None |
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indents = [0] |
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while 1: # loop over lines in stream |
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line = readline() |
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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 line[pos] in '#\r\n': # skip comments or blank lines |
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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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indents = indents[:-1] |
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yield (DEDENT, '', (lnum, pos), (lnum, pos), line) |
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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 numchars 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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yield (parenlev > 0 and NL or NEWLINE, |
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token, spos, epos, line) |
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elif initial == '#': |
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yield (COMMENT, token, spos, epos, line) |
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elif token in ("'''", '"""', # triple-quoted |
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"r'''", 'r"""', "R'''", 'R"""', |
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"u'''", 'u"""', "U'''", 'U"""', |
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"ur'''", 'ur"""', "Ur'''", 'Ur"""', |
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"uR'''", 'uR"""', "UR'''", 'UR"""'): |
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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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yield (STRING, token, spos, (lnum, pos), line) |
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else: |
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strstart = (lnum, start) # multiple lines |
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contstr = line[start:] |
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contline = line |
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break |
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elif initial in ("'", '"') or \ |
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token[:2] in ("r'", 'r"', "R'", 'R"', |
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"u'", 'u"', "U'", 'U"') or \ |
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token[:3] in ("ur'", 'ur"', "Ur'", 'Ur"', |
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"uR'", 'uR"', "UR'", 'UR"' ): |
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if token[-1] == '\n': # continued string |
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strstart = (lnum, start) |
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endprog = (endprogs[initial] or endprogs[token[1]] or |
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endprogs[token[2]]) |
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contstr, needcont = line[start:], 1 |
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contline = line |
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break |
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else: # ordinary string |
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yield (STRING, token, spos, epos, line) |
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elif initial in namechars: # ordinary name |
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yield (NAME, token, spos, epos, line) |
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elif initial == '\\': # continued stmt |
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continued = 1 |
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else: |
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if initial in '([{': parenlev = parenlev + 1 |
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elif initial in ')]}': parenlev = parenlev - 1 |
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yield (OP, token, spos, epos, line) |
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else: |
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yield (ERRORTOKEN, line[pos], |
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(lnum, pos), (lnum, pos+1), line) |
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pos = pos + 1 |
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for indent in indents[1:]: # pop remaining indent levels |
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yield (DEDENT, '', (lnum, 0), (lnum, 0), '') |
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yield (ENDMARKER, '', (lnum, 0), (lnum, 0), '') |
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if __name__ == '__main__': # testing |
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import sys |
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if len(sys.argv) > 1: tokenize(open(sys.argv[1]).readline) |
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else: tokenize(sys.stdin.readline)
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