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Diffstat (limited to 'lib/python2.7/tabnanny.py')
| -rwxr-xr-x | lib/python2.7/tabnanny.py | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/lib/python2.7/tabnanny.py b/lib/python2.7/tabnanny.py new file mode 100755 index 0000000..76665ac --- /dev/null +++ b/lib/python2.7/tabnanny.py @@ -0,0 +1,329 @@ +#! /usr/bin/env python + +"""The Tab Nanny despises ambiguous indentation. She knows no mercy. + +tabnanny -- Detection of ambiguous indentation + +For the time being this module is intended to be called as a script. +However it is possible to import it into an IDE and use the function +check() described below. + +Warning: The API provided by this module is likely to change in future +releases; such changes may not be backward compatible. +""" + +# Released to the public domain, by Tim Peters, 15 April 1998. + +# XXX Note: this is now a standard library module. +# XXX The API needs to undergo changes however; the current code is too +# XXX script-like. This will be addressed later. + +__version__ = "6" + +import os +import sys +import getopt +import tokenize +if not hasattr(tokenize, 'NL'): + raise ValueError("tokenize.NL doesn't exist -- tokenize module too old") + +__all__ = ["check", "NannyNag", "process_tokens"] + +verbose = 0 +filename_only = 0 + +def errprint(*args): + sep = "" + for arg in args: + sys.stderr.write(sep + str(arg)) + sep = " " + sys.stderr.write("\n") + +def main(): + global verbose, filename_only + try: + opts, args = getopt.getopt(sys.argv[1:], "qv") + except getopt.error, msg: + errprint(msg) + return + for o, a in opts: + if o == '-q': + filename_only = filename_only + 1 + if o == '-v': + verbose = verbose + 1 + if not args: + errprint("Usage:", sys.argv[0], "[-v] file_or_directory ...") + return + for arg in args: + check(arg) + +class NannyNag(Exception): + """ + Raised by tokeneater() if detecting an ambiguous indent. + Captured and handled in check(). + """ + def __init__(self, lineno, msg, line): + self.lineno, self.msg, self.line = lineno, msg, line + def get_lineno(self): + return self.lineno + def get_msg(self): + return self.msg + def get_line(self): + return self.line + +def check(file): + """check(file_or_dir) + + If file_or_dir is a directory and not a symbolic link, then recursively + descend the directory tree named by file_or_dir, checking all .py files + along the way. If file_or_dir is an ordinary Python source file, it is + checked for whitespace related problems. The diagnostic messages are + written to standard output using the print statement. + """ + + if os.path.isdir(file) and not os.path.islink(file): + if verbose: + print "%r: listing directory" % (file,) + names = os.listdir(file) + for name in names: + fullname = os.path.join(file, name) + if (os.path.isdir(fullname) and + not os.path.islink(fullname) or + os.path.normcase(name[-3:]) == ".py"): + check(fullname) + return + + try: + f = open(file) + except IOError, msg: + errprint("%r: I/O Error: %s" % (file, msg)) + return + + if verbose > 1: + print "checking %r ..." % file + + try: + process_tokens(tokenize.generate_tokens(f.readline)) + + except tokenize.TokenError, msg: + errprint("%r: Token Error: %s" % (file, msg)) + return + + except IndentationError, msg: + errprint("%r: Indentation Error: %s" % (file, msg)) + return + + except NannyNag, nag: + badline = nag.get_lineno() + line = nag.get_line() + if verbose: + print "%r: *** Line %d: trouble in tab city! ***" % (file, badline) + print "offending line: %r" % (line,) + print nag.get_msg() + else: + if ' ' in file: file = '"' + file + '"' + if filename_only: print file + else: print file, badline, repr(line) + return + + if verbose: + print "%r: Clean bill of health." % (file,) + +class Whitespace: + # the characters used for space and tab + S, T = ' \t' + + # members: + # raw + # the original string + # n + # the number of leading whitespace characters in raw + # nt + # the number of tabs in raw[:n] + # norm + # the normal form as a pair (count, trailing), where: + # count + # a tuple such that raw[:n] contains count[i] + # instances of S * i + T + # trailing + # the number of trailing spaces in raw[:n] + # It's A Theorem that m.indent_level(t) == + # n.indent_level(t) for all t >= 1 iff m.norm == n.norm. + # is_simple + # true iff raw[:n] is of the form (T*)(S*) + + def __init__(self, ws): + self.raw = ws + S, T = Whitespace.S, Whitespace.T + count = [] + b = n = nt = 0 + for ch in self.raw: + if ch == S: + n = n + 1 + b = b + 1 + elif ch == T: + n = n + 1 + nt = nt + 1 + if b >= len(count): + count = count + [0] * (b - len(count) + 1) + count[b] = count[b] + 1 + b = 0 + else: + break + self.n = n + self.nt = nt + self.norm = tuple(count), b + self.is_simple = len(count) <= 1 + + # return length of longest contiguous run of spaces (whether or not + # preceding a tab) + def longest_run_of_spaces(self): + count, trailing = self.norm + return max(len(count)-1, trailing) + + def indent_level(self, tabsize): + # count, il = self.norm + # for i in range(len(count)): + # if count[i]: + # il = il + (i/tabsize + 1)*tabsize * count[i] + # return il + + # quicker: + # il = trailing + sum (i/ts + 1)*ts*count[i] = + # trailing + ts * sum (i/ts + 1)*count[i] = + # trailing + ts * sum i/ts*count[i] + count[i] = + # trailing + ts * [(sum i/ts*count[i]) + (sum count[i])] = + # trailing + ts * [(sum i/ts*count[i]) + num_tabs] + # and note that i/ts*count[i] is 0 when i < ts + + count, trailing = self.norm + il = 0 + for i in range(tabsize, len(count)): + il = il + i/tabsize * count[i] + return trailing + tabsize * (il + self.nt) + + # return true iff self.indent_level(t) == other.indent_level(t) + # for all t >= 1 + def equal(self, other): + return self.norm == other.norm + + # return a list of tuples (ts, i1, i2) such that + # i1 == self.indent_level(ts) != other.indent_level(ts) == i2. + # Intended to be used after not self.equal(other) is known, in which + # case it will return at least one witnessing tab size. + def not_equal_witness(self, other): + n = max(self.longest_run_of_spaces(), + other.longest_run_of_spaces()) + 1 + a = [] + for ts in range(1, n+1): + if self.indent_level(ts) != other.indent_level(ts): + a.append( (ts, + self.indent_level(ts), + other.indent_level(ts)) ) + return a + + # Return True iff self.indent_level(t) < other.indent_level(t) + # for all t >= 1. + # The algorithm is due to Vincent Broman. + # Easy to prove it's correct. + # XXXpost that. + # Trivial to prove n is sharp (consider T vs ST). + # Unknown whether there's a faster general way. I suspected so at + # first, but no longer. + # For the special (but common!) case where M and N are both of the + # form (T*)(S*), M.less(N) iff M.len() < N.len() and + # M.num_tabs() <= N.num_tabs(). Proof is easy but kinda long-winded. + # XXXwrite that up. + # Note that M is of the form (T*)(S*) iff len(M.norm[0]) <= 1. + def less(self, other): + if self.n >= other.n: + return False + if self.is_simple and other.is_simple: + return self.nt <= other.nt + n = max(self.longest_run_of_spaces(), + other.longest_run_of_spaces()) + 1 + # the self.n >= other.n test already did it for ts=1 + for ts in range(2, n+1): + if self.indent_level(ts) >= other.indent_level(ts): + return False + return True + + # return a list of tuples (ts, i1, i2) such that + # i1 == self.indent_level(ts) >= other.indent_level(ts) == i2. + # Intended to be used after not self.less(other) is known, in which + # case it will return at least one witnessing tab size. + def not_less_witness(self, other): + n = max(self.longest_run_of_spaces(), + other.longest_run_of_spaces()) + 1 + a = [] + for ts in range(1, n+1): + if self.indent_level(ts) >= other.indent_level(ts): + a.append( (ts, + self.indent_level(ts), + other.indent_level(ts)) ) + return a + +def format_witnesses(w): + firsts = map(lambda tup: str(tup[0]), w) + prefix = "at tab size" + if len(w) > 1: + prefix = prefix + "s" + return prefix + " " + ', '.join(firsts) + +def process_tokens(tokens): + INDENT = tokenize.INDENT + DEDENT = tokenize.DEDENT + NEWLINE = tokenize.NEWLINE + JUNK = tokenize.COMMENT, tokenize.NL + indents = [Whitespace("")] + check_equal = 0 + + for (type, token, start, end, line) in tokens: + if type == NEWLINE: + # a program statement, or ENDMARKER, will eventually follow, + # after some (possibly empty) run of tokens of the form + # (NL | COMMENT)* (INDENT | DEDENT+)? + # If an INDENT appears, setting check_equal is wrong, and will + # be undone when we see the INDENT. + check_equal = 1 + + elif type == INDENT: + check_equal = 0 + thisguy = Whitespace(token) + if not indents[-1].less(thisguy): + witness = indents[-1].not_less_witness(thisguy) + msg = "indent not greater e.g. " + format_witnesses(witness) + raise NannyNag(start[0], msg, line) + indents.append(thisguy) + + elif type == DEDENT: + # there's nothing we need to check here! what's important is + # that when the run of DEDENTs ends, the indentation of the + # program statement (or ENDMARKER) that triggered the run is + # equal to what's left at the top of the indents stack + + # Ouch! This assert triggers if the last line of the source + # is indented *and* lacks a newline -- then DEDENTs pop out + # of thin air. + # assert check_equal # else no earlier NEWLINE, or an earlier INDENT + check_equal = 1 + + del indents[-1] + + elif check_equal and type not in JUNK: + # this is the first "real token" following a NEWLINE, so it + # must be the first token of the next program statement, or an + # ENDMARKER; the "line" argument exposes the leading whitespace + # for this statement; in the case of ENDMARKER, line is an empty + # string, so will properly match the empty string with which the + # "indents" stack was seeded + check_equal = 0 + thisguy = Whitespace(line) + if not indents[-1].equal(thisguy): + witness = indents[-1].not_equal_witness(thisguy) + msg = "indent not equal e.g. " + format_witnesses(witness) + raise NannyNag(start[0], msg, line) + + +if __name__ == '__main__': + main() |