cpython-lru_cache-weakref: Tools/scripts/ndiff.py annotate

annotate Tools/scripts/ndiff.py @ 8831:00a6bb65ff29 legacy-trunk

Getting rid of this ancient stuff.

author	Guido van Rossum <guido@python.org>
date	Wed, 05 Aug 1998 21:10:09 +0000
parents	32bc17f7c77b
children	30c94cd49a68

rev	line source
8228 9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	1 #! /usr/bin/env python
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	2
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	3 # Released to the public domain $JustDate: 3/16/98 $,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	4 # by Tim Peters (email tim_one@email.msn.com).
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	5
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	6 # ndiff file1 file2 -- a human-friendly file differencer.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	7
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	8 # $Revision$
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	9
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	10 # SequenceMatcher tries to compute a "human-friendly diff" between
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	11 # two sequences (chiefly picturing a file as a sequence of lines,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	12 # and a line as a sequence of characters, here). Unlike UNIX(tm) diff,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	13 # e.g., the fundamental notion is the longest contiguous & junk-free
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	14 # matching subsequence. That's what catches peoples' eyes. The
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	15 # Windows(tm) windiff has another interesting notion, pairing up elements
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	16 # that appear uniquely in each sequence. That, and the method here,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	17 # appear to yield more intuitive difference reports than does diff. This
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	18 # method appears to be the least vulnerable to synching up on blocks
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	19 # of "junk lines", though (like blank lines in ordinary text files,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	20 # or maybe "<P>" lines in HTML files). That may be because this is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	21 # the only method of the 3 that has a concept of "junk" <wink>.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	22 #
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	23 # Note that ndiff makes no claim to produce a minimal diff. To the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	24 # contrary, minimal diffs are often counter-intuitive, because they
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	25 # synch up anywhere possible, sometimes accidental matches 100 pages
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	26 # apart. Restricting synch points to contiguous matches preserves some
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	27 # notion of locality, at the occasional cost of producing a longer diff.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	28 #
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	29 # With respect to junk, an earlier verion of ndiff simply refused to
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	30 # start a match with a junk element. The result was cases like this:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	31 # before: private Thread currentThread;
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	32 # after: private volatile Thread currentThread;
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	33 # If you consider whitespace to be junk, the longest continguous match
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	34 # not starting with junk is "e Thread currentThread". So ndiff reported
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	35 # that "e volatil" was inserted between the 't' and the 'e' in "private".
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	36 # While an accurate view, to people that's absurd. The current version
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	37 # looks for matching blocks that are entirely junk-free, then extends the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	38 # longest one of those as far as possible but only with matching junk.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	39 # So now "currentThread" is matched, then extended to suck up the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	40 # preceding blank; then "private" is matched, and extended to suck up the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	41 # following blank; then "Thread" is matched; and finally ndiff reports
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	42 # that "volatile " was inserted before "Thread". The only quibble
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	43 # remaining is that perhaps it was really the case that " volative"
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	44 # was inserted after "private". I can live with that <wink>.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	45 #
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	46 # NOTE on the output: From an ndiff report,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	47 # 1) The first file can be recovered by retaining only lines that begin
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	48 # with " " or "- ", and deleting those 2-character prefixes.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	49 # 2) The second file can be recovered similarly, but by retaining only
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	50 # " " and "+ " lines.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	51 # 3) Lines beginning with "? " attempt to guide the eye to intraline
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	52 # differences, and were not present in either input file.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	53 #
8285 32bc17f7c77b Add the specific sed statement to recover the second output file to Guido van Rossum <guido@python.org> parents: 8228 diff changeset	54 # COROLLARY:
32bc17f7c77b Add the specific sed statement to recover the second output file to Guido van Rossum <guido@python.org> parents: 8228 diff changeset	55 # On Unix, the second file can be recovered by piping the output through
32bc17f7c77b Add the specific sed statement to recover the second output file to Guido van Rossum <guido@python.org> parents: 8228 diff changeset	56 # sed -n '/^[+ ] /s/^..//p'
32bc17f7c77b Add the specific sed statement to recover the second output file to Guido van Rossum <guido@python.org> parents: 8228 diff changeset	57 # Modifications to recover the first file are left as an exercise for
32bc17f7c77b Add the specific sed statement to recover the second output file to Guido van Rossum <guido@python.org> parents: 8228 diff changeset	58 # the reader.
32bc17f7c77b Add the specific sed statement to recover the second output file to Guido van Rossum <guido@python.org> parents: 8228 diff changeset	59 #
8228 9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	60 # NOTE on junk: the module-level names
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	61 # IS_LINE_JUNK
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	62 # IS_CHARACTER_JUNK
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	63 # can be set to any functions you like. The first one should accept
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	64 # a single string argument, and return true iff the string is junk.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	65 # The default is whether the regexp r"\s#?\s$" matches (i.e., a
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	66 # line without visible characters, except for at most one splat).
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	67 # The second should accept a string of length 1 etc. The default is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	68 # whether the character is a blank or tab (note: bad idea to include
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	69 # newline in this!).
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	70 #
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	71 # After setting those, you can call fcompare(f1name, f2name) with the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	72 # names of the files you want to compare. The difference report
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	73 # is sent to stdout. Or you can call main(), which expects to find
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	74 # (exactly) the two file names in sys.argv.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	75
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	76 import string
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	77 TRACE = 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	78
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	79 # define what "junk" means
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	80 import re
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	81
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	82 def IS_LINE_JUNK(line, pat=re.compile(r"\s#?\s$").match):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	83 return pat(line) is not None
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	84
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	85 def IS_CHARACTER_JUNK(ch, ws=" \t"):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	86 return ch in ws
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	87
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	88 del re
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	89
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	90 class SequenceMatcher:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	91 def __init__(self, isjunk=None, a='', b=''):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	92 # Members:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	93 # a
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	94 # first sequence
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	95 # b
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	96 # second sequence; differences are computed as "what do
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	97 # we need to do to 'a' to change it into 'b'?"
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	98 # b2j
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	99 # for x in b, b2j[x] is a list of the indices (into b)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	100 # at which x appears; junk elements do not appear
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	101 # b2jhas
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	102 # b2j.has_key
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	103 # fullbcount
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	104 # for x in b, fullbcount[x] == the number of times x
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	105 # appears in b; only materialized if really needed (used
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	106 # only for computing quick_ratio())
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	107 # matching_blocks
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	108 # a list of (i, j, k) triples, where a[i:i+k] == b[j:j+k];
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	109 # ascending & non-overlapping in i and in j; terminated by
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	110 # a dummy (len(a), len(b), 0) sentinel
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	111 # opcodes
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	112 # a list of (tag, i1, i2, j1, j2) tuples, where tag is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	113 # one of
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	114 # 'replace' a[i1:i2] should be replaced by b[j1:j2]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	115 # 'delete' a[i1:i2] should be deleted
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	116 # 'insert' b[j1:j2] should be inserted
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	117 # 'equal' a[i1:i2] == b[j1:j2]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	118 # isjunk
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	119 # a user-supplied function taking a sequence element and
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	120 # returning true iff the element is "junk" -- this has
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	121 # subtle but helpful effects on the algorithm, which I'll
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	122 # get around to writing up someday <0.9 wink>.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	123 # DON'T USE! Only __chain_b uses this. Use isbjunk.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	124 # isbjunk
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	125 # for x in b, isbjunk(x) == isjunk(x) but much faster;
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	126 # it's really the has_key method of a hidden dict.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	127 # DOES NOT WORK for x in a!
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	128
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	129 self.isjunk = isjunk
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	130 self.a = self.b = None
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	131 self.set_seqs(a, b)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	132
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	133 def set_seqs(self, a, b):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	134 self.set_seq1(a)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	135 self.set_seq2(b)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	136
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	137 def set_seq1(self, a):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	138 if a is self.a:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	139 return
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	140 self.a = a
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	141 self.matching_blocks = self.opcodes = None
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	142
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	143 def set_seq2(self, b):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	144 if b is self.b:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	145 return
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	146 self.b = b
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	147 self.matching_blocks = self.opcodes = None
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	148 self.fullbcount = None
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	149 self.__chain_b()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	150
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	151 # for each element x in b, set b2j[x] to a list of the indices in
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	152 # b where x appears; the indices are in increasing order; note that
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	153 # the number of times x appears in b is len(b2j[x]) ...
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	154 # when self.isjunk is defined, junk elements don't show up in this
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	155 # map at all, which stops the central find_longest_match method
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	156 # from starting any matching block at a junk element ...
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	157 # also creates the fast isbjunk function ...
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	158 # note that this is only called when b changes; so for cross-product
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	159 # kinds of matches, it's best to call set_seq2 once, then set_seq1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	160 # repeatedly
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	161
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	162 def __chain_b(self):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	163 # Because isjunk is a user-defined (not C) function, and we test
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	164 # for junk a LOT, it's important to minimize the number of calls.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	165 # Before the tricks described here, __chain_b was by far the most
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	166 # time-consuming routine in the whole module! If anyone sees
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	167 # Jim Roskind, thank him again for profile.py -- I never would
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	168 # have guessed that.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	169 # The first trick is to build b2j ignoring the possibility
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	170 # of junk. I.e., we don't call isjunk at all yet. Throwing
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	171 # out the junk later is much cheaper than building b2j "right"
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	172 # from the start.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	173 b = self.b
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	174 self.b2j = b2j = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	175 self.b2jhas = b2jhas = b2j.has_key
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	176 for i in xrange(0, len(b)):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	177 elt = b[i]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	178 if b2jhas(elt):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	179 b2j[elt].append(i)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	180 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	181 b2j[elt] = [i]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	182
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	183 # Now b2j.keys() contains elements uniquely, and especially when
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	184 # the sequence is a string, that's usually a good deal smaller
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	185 # than len(string). The difference is the number of isjunk calls
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	186 # saved.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	187 isjunk, junkdict = self.isjunk, {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	188 if isjunk:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	189 for elt in b2j.keys():
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	190 if isjunk(elt):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	191 junkdict[elt] = 1 # value irrelevant; it's a set
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	192 del b2j[elt]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	193
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	194 # Now for x in b, isjunk(x) == junkdict.has_key(x), but the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	195 # latter is much faster. Note too that while there may be a
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	196 # lot of junk in the sequence, the number of unique junk
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	197 # elements is probably small. So the memory burden of keeping
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	198 # this dict alive is likely trivial compared to the size of b2j.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	199 self.isbjunk = junkdict.has_key
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	200
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	201 def find_longest_match(self, alo, ahi, blo, bhi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	202 """Find longest matching block in a[alo:ahi] and b[blo:bhi].
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	203
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	204 If isjunk is not defined:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	205
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	206 Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	207 alo <= i <= i+k <= ahi
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	208 blo <= j <= j+k <= bhi
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	209 and for all (i',j',k') meeting those conditions,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	210 k >= k'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	211 i <= i'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	212 and if i == i', j <= j'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	213 In other words, of all maximal matching blocks, returns one
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	214 that starts earliest in a, and of all those maximal matching
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	215 blocks that start earliest in a, returns the one that starts
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	216 earliest in b.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	217
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	218 If isjunk is defined, first the longest matching block is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	219 determined as above, but with the additional restriction that
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	220 no junk element appears in the block. Then that block is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	221 extended as far as possible by matching (only) junk elements on
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	222 both sides. So the resulting block never matches on junk except
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	223 as identical junk happens to be adjacent to an "interesting"
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	224 match.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	225
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	226 If no blocks match, returns (alo, blo, 0).
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	227 """
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	228
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	229 # CAUTION: stripping common prefix or suffix would be incorrect.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	230 # E.g.,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	231 # ab
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	232 # acab
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	233 # Longest matching block is "ab", but if common prefix is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	234 # stripped, it's "a" (tied with "b"). UNIX(tm) diff does so
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	235 # strip, so ends up claiming that ab is changed to acab by
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	236 # inserting "ca" in the middle. That's minimal but unintuitive:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	237 # "it's obvious" that someone inserted "ac" at the front.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	238 # Windiff ends up at the same place as diff, but by pairing up
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	239 # the unique 'b's and then matching the first two 'a's.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	240
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	241 # find longest junk-free match
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	242 a, b, b2j, isbjunk = self.a, self.b, self.b2j, self.isbjunk
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	243 besti, bestj, bestsize = alo, blo, 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	244 for i in xrange(alo, ahi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	245 # check for longest match starting at a[i]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	246 if i + bestsize >= ahi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	247 # we're too far right to get a new best
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	248 break
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	249 # look at all instances of a[i] in b; note that because
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	250 # b2j has no junk keys, the loop is skipped if a[i] is junk
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	251 for j in b2j.get(a[i], []):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	252 # a[i] matches b[j]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	253 if j < blo:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	254 continue
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	255 if j + bestsize >= bhi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	256 # we're too far right to get a new best, here or
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	257 # anywhere to the right
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	258 break
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	259 if a[i + bestsize] != b[j + bestsize]:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	260 # can't be longer match; this test is not necessary
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	261 # for correctness, but is a huge win for efficiency
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	262 continue
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	263 # set k to length of match
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	264 k = 1 # a[i] == b[j] already known
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	265 while i + k < ahi and j + k < bhi and \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	266 a[i+k] == b[j+k] and not isbjunk(b[j+k]):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	267 k = k + 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	268 if k > bestsize:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	269 besti, bestj, bestsize = i, j, k
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	270 if i + bestsize >= ahi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	271 # only time in my life I really wanted a
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	272 # labelled break <wink> -- we're done with
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	273 # both loops now
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	274 break
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	275
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	276 # Now that we have a wholly interesting match (albeit possibly
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	277 # empty!), we may as well suck up the matching junk on each
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	278 # side of it too. Can't think of a good reason not to, and it
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	279 # saves post-processing the (possibly considerable) expense of
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	280 # figuring out what to do with it. In the case of an empty
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	281 # interesting match, this is clearly the right thing to do,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	282 # because no other kind of match is possible in the regions.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	283 while besti > alo and bestj > blo and \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	284 isbjunk(b[bestj-1]) and \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	285 a[besti-1] == b[bestj-1]:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	286 besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	287 while besti+bestsize < ahi and bestj+bestsize < bhi and \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	288 isbjunk(b[bestj+bestsize]) and \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	289 a[besti+bestsize] == b[bestj+bestsize]:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	290 bestsize = bestsize + 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	291
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	292 if TRACE:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	293 print "get_matching_blocks", alo, ahi, blo, bhi
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	294 print " returns", besti, bestj, bestsize
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	295 return besti, bestj, bestsize
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	296
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	297 # A different implementation, using a binary doubling technique that
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	298 # does far fewer element compares (trades 'em for integer compares),
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	299 # and has n*lg n worst-case behavior. Alas, the code is much harder
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	300 # to follow (the details are tricky!), and in most cases I've seen,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	301 # it takes at least 50% longer than the "clever dumb" method above;
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	302 # probably due to creating layers of small dicts.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	303 # NOTE: this no longer matches the version above wrt junk; remains
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	304 # too unpromising to update it; someday, though ...
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	305
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	306 # def find_longest_match(self, alo, ahi, blo, bhi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	307 # """Find longest matching block in a[alo:ahi] and b[blo:bhi].
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	308 #
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	309 # Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	310 # alo <= i <= i+k <= ahi
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	311 # blo <= j <= j+k <= bhi
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	312 # and for all (i',j',k') meeting those conditions,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	313 # k >= k'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	314 # i <= i'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	315 # and if i == i', j <= j'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	316 # In other words, of all maximal matching blocks, returns one
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	317 # that starts earliest in a, and of all those maximal matching
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	318 # blocks that start earliest in a, returns the one that starts
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	319 # earliest in b.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	320 #
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	321 # If no blocks match, returns (alo, blo, 0).
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	322 # """
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	323 #
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	324 # a, b2j = self.a, self.b2j
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	325 # # alljs[size][i] is a set of all j's s.t. a[i:i+len] matches
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	326 # # b[j:j+len]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	327 # alljs = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	328 # alljs[1] = js = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	329 # ahits = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	330 # for i in xrange(alo, ahi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	331 # elt = a[i]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	332 # if ahits.has_key(elt):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	333 # js[i] = ahits[elt]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	334 # continue
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	335 # if b2j.has_key(elt):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	336 # in_range = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	337 # for j in b2j[elt]:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	338 # if j >= blo:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	339 # if j >= bhi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	340 # break
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	341 # in_range[j] = 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	342 # if in_range:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	343 # ahits[elt] = js[i] = in_range
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	344 # del ahits
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	345 # size = 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	346 # while js:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	347 # oldsize = size
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	348 # size = size + size
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	349 # oldjs = js
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	350 # alljs[size] = js = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	351 # for i in oldjs.keys():
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	352 # # i has matches of size oldsize
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	353 # if not oldjs.has_key(i + oldsize):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	354 # # can't double it
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	355 # continue
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	356 # second_js = oldjs[i + oldsize]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	357 # answer = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	358 # for j in oldjs[i].keys():
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	359 # if second_js.has_key(j + oldsize):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	360 # answer[j] = 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	361 # if answer:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	362 # js[i] = answer
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	363 # del alljs[size]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	364 # size = size >> 1 # max power of 2 with a match
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	365 # if not size:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	366 # return alo, blo, 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	367 # besti, bestj, bestsize = alo, blo, 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	368 # fatis = alljs[size].keys()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	369 # fatis.sort()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	370 # for i in fatis:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	371 # # figure out longest match starting at a[i]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	372 # totalsize = halfsize = size
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	373 # # i has matches of len totalsize at the indices in js
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	374 # js = alljs[size][i].keys()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	375 # while halfsize > 1:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	376 # halfsize = halfsize >> 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	377 # # is there a match of len halfsize starting at
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	378 # # i + totalsize?
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	379 # newjs = []
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	380 # if alljs[halfsize].has_key(i + totalsize):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	381 # second_js = alljs[halfsize][i + totalsize]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	382 # for j in js:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	383 # if second_js.has_key(j + totalsize):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	384 # newjs.append(j)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	385 # if newjs:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	386 # totalsize = totalsize + halfsize
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	387 # js = newjs
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	388 # if totalsize > bestsize:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	389 # besti, bestj, bestsize = i, min(js), totalsize
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	390 # return besti, bestj, bestsize
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	391
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	392 def get_matching_blocks(self):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	393 if self.matching_blocks is not None:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	394 return self.matching_blocks
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	395 self.matching_blocks = []
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	396 la, lb = len(self.a), len(self.b)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	397 self.__helper(0, la, 0, lb, self.matching_blocks)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	398 self.matching_blocks.append( (la, lb, 0) )
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	399 if TRACE:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	400 print '*** matching blocks', self.matching_blocks
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	401 return self.matching_blocks
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	402
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	403 # builds list of matching blocks covering a[alo:ahi] and
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	404 # b[blo:bhi], appending them in increasing order to answer
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	405
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	406 def __helper(self, alo, ahi, blo, bhi, answer):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	407 i, j, k = x = self.find_longest_match(alo, ahi, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	408 # a[alo:i] vs b[blo:j] unknown
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	409 # a[i:i+k] same as b[j:j+k]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	410 # a[i+k:ahi] vs b[j+k:bhi] unknown
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	411 if k:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	412 if alo < i and blo < j:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	413 self.__helper(alo, i, blo, j, answer)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	414 answer.append( x )
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	415 if i+k < ahi and j+k < bhi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	416 self.__helper(i+k, ahi, j+k, bhi, answer)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	417
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	418 def ratio(self):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	419 """Return a measure of the sequences' similarity (float in [0,1]).
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	420
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	421 Where T is the total number of elements in both sequences, and
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	422 M is the number of matches, this is 2*M / T.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	423 Note that this is 1 if the sequences are identical, and 0 if
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	424 they have nothing in common.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	425 """
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	426
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	427 matches = reduce(lambda sum, triple: sum + triple[-1],
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	428 self.get_matching_blocks(), 0)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	429 return 2.0 * matches / (len(self.a) + len(self.b))
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	430
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	431 def quick_ratio(self):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	432 """Return an upper bound on ratio() relatively quickly."""
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	433 # viewing a and b as multisets, set matches to the cardinality
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	434 # of their intersection; this counts the number of matches
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	435 # without regard to order, so is clearly an upper bound
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	436 if self.fullbcount is None:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	437 self.fullbcount = fullbcount = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	438 for elt in self.b:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	439 fullbcount[elt] = fullbcount.get(elt, 0) + 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	440 fullbcount = self.fullbcount
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	441 # avail[x] is the number of times x appears in 'b' less the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	442 # number of times we've seen it in 'a' so far ... kinda
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	443 avail = {}
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	444 availhas, matches = avail.has_key, 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	445 for elt in self.a:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	446 if availhas(elt):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	447 numb = avail[elt]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	448 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	449 numb = fullbcount.get(elt, 0)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	450 avail[elt] = numb - 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	451 if numb > 0:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	452 matches = matches + 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	453 return 2.0 * matches / (len(self.a) + len(self.b))
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	454
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	455 def real_quick_ratio(self):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	456 """Return an upper bound on ratio() very quickly"""
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	457 la, lb = len(self.a), len(self.b)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	458 # can't have more matches than the number of elements in the
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	459 # shorter sequence
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	460 return 2.0 * min(la, lb) / (la + lb)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	461
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	462 def get_opcodes(self):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	463 if self.opcodes is not None:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	464 return self.opcodes
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	465 i = j = 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	466 self.opcodes = answer = []
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	467 for ai, bj, size in self.get_matching_blocks():
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	468 # invariant: we've pumped out correct diffs to change
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	469 # a[:i] into b[:j], and the next matching block is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	470 # a[ai:ai+size] == b[bj:bj+size]. So we need to pump
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	471 # out a diff to change a[i:ai] into b[j:bj], pump out
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	472 # the matching block, and move (i,j) beyond the match
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	473 tag = ''
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	474 if i < ai and j < bj:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	475 tag = 'replace'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	476 elif i < ai:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	477 tag = 'delete'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	478 elif j < bj:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	479 tag = 'insert'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	480 if tag:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	481 answer.append( (tag, i, ai, j, bj) )
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	482 i, j = ai+size, bj+size
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	483 # the list of matching blocks is terminated by a
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	484 # sentinel with size 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	485 if size:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	486 answer.append( ('equal', ai, i, bj, j) )
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	487 return answer
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	488
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	489 # meant for dumping lines
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	490 def dump(tag, x, lo, hi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	491 for i in xrange(lo, hi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	492 print tag, x[i],
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	493
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	494 # figure out which mark to stick under characters in lines that
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	495 # have changed (blank = same, - = deleted, + = inserted, ^ = replaced)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	496 _combine = { ' ': ' ',
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	497 '. ': '-',
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	498 ' .': '+',
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	499 '..': '^' }
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	500
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	501 def plain_replace(a, alo, ahi, b, blo, bhi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	502 assert alo < ahi and blo < bhi
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	503 # dump the shorter block first -- reduces the burden on short-term
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	504 # memory if the blocks are of very different sizes
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	505 if bhi - blo < ahi - alo:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	506 dump('+', b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	507 dump('-', a, alo, ahi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	508 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	509 dump('-', a, alo, ahi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	510 dump('+', b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	511
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	512 # When replacing one block of lines with another, this guy searches
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	513 # the blocks for similar lines; the best-matching pair (if any) is
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	514 # used as a synch point, and intraline difference marking is done on
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	515 # the similar pair. Lots of work, but often worth it.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	516
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	517 def fancy_replace(a, alo, ahi, b, blo, bhi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	518 if TRACE:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	519 print '*** fancy_replace', alo, ahi, blo, bhi
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	520 dump('>', a, alo, ahi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	521 dump('<', b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	522
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	523 # don't synch up unless the lines have a similarity score of at
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	524 # least cutoff; best_ratio tracks the best score seen so far
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	525 best_ratio, cutoff = 0.74, 0.75
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	526 cruncher = SequenceMatcher(IS_CHARACTER_JUNK)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	527 eqi, eqj = None, None # 1st indices of equal lines (if any)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	528
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	529 # search for the pair that matches best without being identical
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	530 # (identical lines must be junk lines, & we don't want to synch up
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	531 # on junk -- unless we have to)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	532 for j in xrange(blo, bhi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	533 bj = b[j]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	534 cruncher.set_seq2(bj)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	535 for i in xrange(alo, ahi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	536 ai = a[i]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	537 if ai == bj:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	538 if eqi is None:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	539 eqi, eqj = i, j
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	540 continue
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	541 cruncher.set_seq1(ai)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	542 # computing similarity is expensive, so use the quick
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	543 # upper bounds first -- have seen this speed up messy
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	544 # compares by a factor of 3.
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	545 # note that ratio() is only expensive to compute the first
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	546 # time it's called on a sequence pair; the expensive part
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	547 # of the computation is cached by cruncher
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	548 if cruncher.real_quick_ratio() > best_ratio and \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	549 cruncher.quick_ratio() > best_ratio and \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	550 cruncher.ratio() > best_ratio:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	551 best_ratio, best_i, best_j = cruncher.ratio(), i, j
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	552 if best_ratio < cutoff:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	553 # no non-identical "pretty close" pair
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	554 if eqi is None:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	555 # no identical pair either -- treat it as a straight replace
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	556 plain_replace(a, alo, ahi, b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	557 return
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	558 # no close pair, but an identical pair -- synch up on that
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	559 best_i, best_j, best_ratio = eqi, eqj, 1.0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	560 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	561 # there's a close pair, so forget the identical pair (if any)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	562 eqi = None
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	563
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	564 # a[best_i] very similar to b[best_j]; eqi is None iff they're not
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	565 # identical
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	566 if TRACE:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	567 print '*** best_ratio', best_ratio, best_i, best_j
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	568 dump('>', a, best_i, best_i+1)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	569 dump('<', b, best_j, best_j+1)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	570
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	571 # pump out diffs from before the synch point
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	572 fancy_helper(a, alo, best_i, b, blo, best_j)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	573
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	574 # do intraline marking on the synch pair
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	575 aelt, belt = a[best_i], b[best_j]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	576 if eqi is None:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	577 # pump out a '-', '+', '?' triple for the synched lines;
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	578 atags = btags = ""
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	579 cruncher.set_seqs(aelt, belt)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	580 for tag, ai1, ai2, bj1, bj2 in cruncher.get_opcodes():
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	581 la, lb = ai2 - ai1, bj2 - bj1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	582 if tag == 'replace':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	583 atags = atags + '.' * la
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	584 btags = btags + '.' * lb
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	585 elif tag == 'delete':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	586 atags = atags + '.' * la
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	587 elif tag == 'insert':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	588 btags = btags + '.' * lb
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	589 elif tag == 'equal':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	590 atags = atags + ' ' * la
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	591 btags = btags + ' ' * lb
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	592 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	593 raise ValueError, 'unknown tag ' + `tag`
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	594 la, lb = len(atags), len(btags)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	595 if la < lb:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	596 atags = atags + ' ' * (lb - la)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	597 elif lb < la:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	598 btags = btags + ' ' * (la - lb)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	599 combined = map(lambda x,y: _combine[x+y], atags, btags)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	600 print '-', aelt, '+', belt, '?', \
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	601 string.rstrip(string.join(combined, ''))
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	602 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	603 # the synch pair is identical
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	604 print ' ', aelt,
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	605
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	606 # pump out diffs from after the synch point
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	607 fancy_helper(a, best_i+1, ahi, b, best_j+1, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	608
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	609 def fancy_helper(a, alo, ahi, b, blo, bhi):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	610 if alo < ahi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	611 if blo < bhi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	612 fancy_replace(a, alo, ahi, b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	613 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	614 dump('-', a, alo, ahi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	615 elif blo < bhi:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	616 dump('+', b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	617
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	618 # open a file & return the file object; gripe and return 0 if it
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	619 # couldn't be opened
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	620 def fopen(fname):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	621 try:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	622 return open(fname, 'r')
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	623 except IOError, detail:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	624 print "couldn't open " + fname + ": " + `detail`
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	625 return 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	626
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	627 # open two files & spray the diff to stdout; return false iff a problem
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	628 def fcompare(f1name, f2name):
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	629 f1 = fopen(f1name)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	630 f2 = fopen(f2name)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	631 if not f1 or not f2:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	632 return 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	633
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	634 a = f1.readlines(); f1.close()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	635 b = f2.readlines(); f2.close()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	636
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	637 cruncher = SequenceMatcher(IS_LINE_JUNK, a, b)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	638 for tag, alo, ahi, blo, bhi in cruncher.get_opcodes():
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	639 if tag == 'replace':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	640 fancy_replace(a, alo, ahi, b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	641 elif tag == 'delete':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	642 dump('-', a, alo, ahi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	643 elif tag == 'insert':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	644 dump('+', b, blo, bhi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	645 elif tag == 'equal':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	646 dump(' ', a, alo, ahi)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	647 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	648 raise ValueError, 'unknown tag ' + `tag`
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	649
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	650 return 1
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	651
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	652 # get file names from argv & compare; return false iff a problem
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	653 def main():
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	654 from sys import argv
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	655 if len(argv) != 3:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	656 print 'need 2 args'
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	657 return 0
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	658 [f1name, f2name] = argv[1:3]
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	659 print '-:', f1name
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	660 print '+:', f2name
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	661 return fcompare(f1name, f2name)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	662
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	663 if __name__ == '__main__':
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	664 if 1:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	665 main()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	666 else:
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	667 import profile, pstats
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	668 statf = "ndiff.pro"
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	669 profile.run("main()", statf)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	670 stats = pstats.Stats(statf)
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	671 stats.strip_dirs().sort_stats('time').print_stats()
9d642a735a13 Adding Tim Peters' ndiff utility. Guido van Rossum <guido@python.org> parents: diff changeset	672

Mercurial > cpython-lru_cache-weakref

annotate Tools/scripts/ndiff.py @ 8831:00a6bb65ff29 legacy-trunk