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authorGuido van Rossum <guido@python.org>1998-03-31 14:31:39 (GMT)
committerGuido van Rossum <guido@python.org>1998-03-31 14:31:39 (GMT)
commit9ab75cbaabd953ba95b2c369dc8ed203bff99c4a (patch)
tree87083200ce1cd038672165868c73c8d05f81f3f2 /Tools/scripts
parenta6bb6be95f4a04fdf7a09fcc92432273877af049 (diff)
downloadcpython-9ab75cbaabd953ba95b2c369dc8ed203bff99c4a.zip
cpython-9ab75cbaabd953ba95b2c369dc8ed203bff99c4a.tar.gz
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Tim Peters' program for checking whether a program's indentation is
sensitive to tab size. Uses a different strategy than tabpolice.py, but has compatible usage.
Diffstat (limited to 'Tools/scripts')
-rwxr-xr-xTools/scripts/tabnanny.py302
1 files changed, 302 insertions, 0 deletions
diff --git a/Tools/scripts/tabnanny.py b/Tools/scripts/tabnanny.py
new file mode 100755
index 0000000..28bd701
--- /dev/null
+++ b/Tools/scripts/tabnanny.py
@@ -0,0 +1,302 @@
+#! /home/guido/python/src/sparc/python
+#! /usr/bin/env python
+
+"""The Tab Nanny despises ambiguous indentation. She knows no mercy.
+
+CAUTION: this version requires Guido's "NL" patch to lib/tokenize.py,
+posted 30-Mar-98. This version will not run at all with an unpatched
+tokenize (it will raise AttributeError while loading), while previous
+versions will run incorrectly with the patched tokenize.
+"""
+
+# Released to the public domain, by Tim Peters, 30 March 1998.
+
+__version__ = "2"
+
+import os
+import sys
+import getopt
+import tokenize
+
+try:
+ tokenize.NL
+except AttributeError:
+ raise AttributeError, "Sorry, I need a version of tokenize.py " \
+ "that supports the NL pseudo-token."
+
+verbose = 0
+
+def main():
+ global verbose
+ try:
+ opts, args = getopt.getopt(sys.argv[1:], "v")
+ except getopt.error, msg:
+ print msg
+ for o, a in opts:
+ if o == '-v':
+ verbose = verbose + 1
+ for arg in args:
+ check(arg)
+
+class NannyNag:
+ 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):
+ if os.path.isdir(file) and not os.path.islink(file):
+ if verbose:
+ print "%s: 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:
+ print "%s: I/O Error: %s" % (`file`, str(msg))
+ return
+
+ if verbose > 1:
+ print "checking", `file`, "..."
+
+ reset_globals()
+ try:
+ tokenize.tokenize(f.readline, tokeneater)
+
+ except tokenize.TokenError, msg:
+ print "%s: Token Error: %s" % (`fname`, str(msg))
+ return
+
+ except NannyNag, nag:
+ badline = nag.get_lineno()
+ line = nag.get_line()
+ if verbose:
+ print "%s: *** Line %d: trouble in tab city! ***" % (
+ `file`, badline)
+ print "offending line:", `line`
+ print nag.get_msg()
+ else:
+ print file, badline, `line`
+ return
+
+ if verbose:
+ print "%s: 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 0
+ 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 0
+ return 1
+
+ # 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):
+ import string
+ firsts = map(lambda tup: str(tup[0]), w)
+ prefix = "at tab size"
+ if len(w) > 1:
+ prefix = prefix + "s"
+ return prefix + " " + string.join(firsts, ', ')
+
+indents = []
+check_equal = 0
+
+def reset_globals():
+ global indents, check_equal
+ check_equal = 0
+ indents = [Whitespace("")]
+
+def tokeneater(type, token, start, end, line,
+ INDENT=tokenize.INDENT,
+ DEDENT=tokenize.DEDENT,
+ NEWLINE=tokenize.NEWLINE,
+ COMMENT=tokenize.COMMENT,
+ NL=tokenize.NL):
+ global indents, check_equal
+
+ # test in decreasing order of frequency, although the check_equal
+ # test *must* be last; INDENT and DEDENT appear equally often
+
+ if type in (COMMENT, NL):
+ # the indentation of these guys is meaningless
+ pass
+
+ elif 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
+ assert check_equal # else no earlier NEWLINE, or an earlier INDENT
+ del indents[-1]
+
+ elif check_equal:
+ # this is the first "real token" following a NEWLINE, so it
+ # must be the first token of the next program statment, 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()
+