diff -r 000000000000 -r de9c2efb9d02 Plugins/CheckerPlugins/Tabnanny/Tabnanny.py --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Plugins/CheckerPlugins/Tabnanny/Tabnanny.py Mon Dec 28 16:03:33 2009 +0000 @@ -0,0 +1,403 @@ +# -*- coding: utf-8 -*- + +""" +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. + +This is a modified version to make the original tabnanny better suitable +for being called from within the eric4 IDE. + +@exception ValueError The tokenize module is too old. +""" + +# 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. + +# +# This is a modified version to make the original tabnanny better suitable +# for being called from within the eric4 IDE. The modifications are as +# follows: +# +# - there is no main function anymore +# - check function has been modified to only accept a filename and return +# a tuple indicating status (1 = an error was found), the filename, the +# linenumber and the error message (boolean, string, string, string). The +# values are only valid, if the status equals 1. +# +# Mofifications copyright (c) 2003 Detlev Offenbach <detlev@die-offenbachs.de> +# + +__version__ = "6_eric" + +import os +import sys +import tokenize +import cStringIO + +import Utilities + +if not hasattr(tokenize, 'NL'): + raise ValueError("tokenize.NL doesn't exist -- tokenize module too old") + +__all__ = ["check", "NannyNag", "process_tokens"] + +class NannyNag(Exception): + """ + Raised by tokeneater() if detecting an ambiguous indent. + Captured and handled in check(). + """ + def __init__(self, lineno, msg, line): + """ + Constructor + + @param lineno Line number of the ambiguous indent. + @param msg Descriptive message assigned to this problem. + @param line The offending source line. + """ + self.lineno, self.msg, self.line = lineno, msg, line + + def get_lineno(self): + """ + Method to retrieve the line number. + + @return The line number (integer) + """ + return self.lineno + + def get_msg(self): + """ + Method to retrieve the message. + + @return The error message (string) + """ + return self.msg + + def get_line(self): + """ + Method to retrieve the offending line. + + @return The line of code (string) + """ + return self.line + +def check(file): + """ + Private function to check one Python source file for whitespace related problems. + + @param file source filename (string) + @return A tuple indicating status (True = an error was found), the + filename, the linenumber and the error message + (boolean, string, string, string). The values are only + valid, if the status is True. + """ + global indents, check_equal + indents = [Whitespace("")] + check_equal = 0 + + try: + f = open(file) + except IOError, msg: + return (True, file, "1", "I/O Error: %s" % unicode(msg)) + + try: + text = Utilities.decode(f.read())[0].encode('utf-8') + finally: + f.close() + + # convert eols + text = Utilities.convertLineEnds(text, os.linesep) + + source = cStringIO.StringIO(text) + try: + process_tokens(tokenize.generate_tokens(source.readline)) + + except tokenize.TokenError, msg: + f.close() + return (True, file, "1", "Token Error: %s" % unicode(msg)) + + except IndentationError, err: + f.close() + return (True, file, err.lineno, "Indentation Error: %s" % unicode(err.msg)) + + except NannyNag, nag: + badline = nag.get_lineno() + line = nag.get_line() + f.close() + return (True, file, str(badline), line) + + except Exception, err: + f.close() + return (True, file, "1", "Unspecific Error: %s" % unicode(err)) + + f.close() + return (False, None, None, None) + +class Whitespace(object): + """ + Class implementing the whitespace checker. + """ + # 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): + """ + Constructor + + @param ws The string to be checked. + """ + 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): + """ + Method to calculate the length of longest contiguous run of spaces. + + @return The length of longest contiguous run of spaces (whether or not + preceding a tab) + """ + count, trailing = self.norm + return max(len(count)-1, trailing) + + def indent_level(self, tabsize): + """ + Method to determine the indentation level. + + @param tabsize The length of a tab stop. (integer) + @return indentation level (integer) + """ + # 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): + """ + Method to compare the indentation levels of two Whitespace objects for equality. + + @param other Whitespace object to compare against. + @return True, if we compare equal against the other Whitespace object. + """ + 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): + """ + Method to calculate a tuple of witnessing tab size. + + Intended to be used after not self.equal(other) is known, in which + case it will return at least one witnessing tab size. + + @param other Whitespace object to calculate against. + @return A list of tuples (ts, i1, i2) such that + i1 == self.indent_level(ts) != other.indent_level(ts) == i2. + """ + 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): + """ + Method to compare the indentation level against another Whitespace objects to + be smaller. + + @param other Whitespace object to compare against. + @return True, if we compare less against the other Whitespace object. + """ + 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): + """ + Method to calculate a tuple of witnessing tab size. + + Intended to be used after not self.less(other is known, in which + case it will return at least one witnessing tab size. + + @param other Whitespace object to calculate against. + @return A list of tuples (ts, i1, i2) such that + i1 == self.indent_level(ts) >= other.indent_level(ts) == i2. + """ + 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): + """ + Function to format the witnesses as a readable string. + + @param w A list of witnesses + @return A formated string of the witnesses. + """ + 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): + """ + Function processing all tokens generated by a tokenizer run. + + @param tokens list of 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)