octave-kai/gnulib-hg: lib/diffseq.h annotate

annotate lib/diffseq.h @ 13243:97c81b93ec7c

diffseq: Accommodate use-case with abstract arrays.

author	Bruno Haible <bruno@clisp.org>
date	Mon, 19 Apr 2010 00:01:18 +0200
parents	c2cbabec01dd
children	89fadace6a88

rev	line source
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	1 /* Analyze differences between two vectors.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	2
12559 c2cbabec01dd update nearly all FSF copyright year lists to include 2010 Jim Meyering <meyering@redhat.com> parents: 12421 diff changeset	3 Copyright (C) 1988-1989, 1992-1995, 2001-2004, 2006-2010 Free Software
c2cbabec01dd update nearly all FSF copyright year lists to include 2010 Jim Meyering <meyering@redhat.com> parents: 12421 diff changeset	4 Foundation, Inc.
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	5
9309 bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 9149 diff changeset	6 This program is free software: you can redistribute it and/or modify
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	7 it under the terms of the GNU General Public License as published by
9309 bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 9149 diff changeset	8 the Free Software Foundation; either version 3 of the License, or
bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 9149 diff changeset	9 (at your option) any later version.
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	10
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	11 This program is distributed in the hope that it will be useful,
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	12 but WITHOUT ANY WARRANTY; without even the implied warranty of
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	14 GNU General Public License for more details.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	15
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	16 You should have received a copy of the GNU General Public License
9309 bbbbbf4cd1c5 Change copyright notice from GPLv2+ to GPLv3+. Bruno Haible <bruno@clisp.org> parents: 9149 diff changeset	17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	18
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	19
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	20 /* The basic idea is to consider two vectors as similar if, when
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	21 transforming the first vector into the second vector through a
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	22 sequence of edits (inserts and deletes of one element each),
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	23 this sequence is short - or equivalently, if the ordered list
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	24 of elements that are untouched by these edits is long. For a
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	25 good introduction to the subject, read about the "Levenshtein
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	26 distance" in Wikipedia.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	27
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	28 The basic algorithm is described in:
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	29 "An O(ND) Difference Algorithm and its Variations", Eugene Myers,
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	30 Algorithmica Vol. 1 No. 2, 1986, pp. 251-266;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	31 see especially section 4.2, which describes the variation used below.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	32
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	33 The basic algorithm was independently discovered as described in:
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	34 "Algorithms for Approximate String Matching", E. Ukkonen,
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	35 Information and Control Vol. 64, 1985, pp. 100-118.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	36
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	37 Unless the 'find_minimal' flag is set, this code uses the TOO_EXPENSIVE
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	38 heuristic, by Paul Eggert, to limit the cost to O(N**1.5 log N)
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	39 at the price of producing suboptimal output for large inputs with
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	40 many differences. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	41
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	42 /* Before including this file, you need to define:
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	43 ELEMENT The element type of the vectors being compared.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	44 EQUAL A two-argument macro that tests two elements for
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	45 equality.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	46 OFFSET A signed integer type sufficient to hold the
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	47 difference between two indices. Usually
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	48 something like ssize_t.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	49 EXTRA_CONTEXT_FIELDS Declarations of fields for 'struct context'.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	50 NOTE_DELETE(ctxt, xoff) Record the removal of the object xvec[xoff].
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	51 NOTE_INSERT(ctxt, yoff) Record the insertion of the object yvec[yoff].
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	52 EARLY_ABORT(ctxt) (Optional) A boolean expression that triggers an
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	53 early abort of the computation.
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	54 USE_HEURISTIC (Optional) Define if you want to support the
9669 8b484b0c3ae6 Add comments about required includes. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	55 heuristic for large vectors.
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	56 It is also possible to you this file with abstract arrays. In this case,
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	57 xvec and yvec are not represented in memory. They only exist conceptually.
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	58 In this case, the list of defines above is amended as follows:
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	59 ELEMENT Undefined.
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	60 EQUAL Undefined.
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	61 XVECREF_YVECREF_EQUAL(ctxt, xoff, yoff)
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	62 A three-argument macro: References xvec[xoff] and
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	63 yvec[yoff] and tests these elements for equality.
9669 8b484b0c3ae6 Add comments about required includes. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	64 Before including this file, you also need to include:
8b484b0c3ae6 Add comments about required includes. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	65 #include <limits.h>
8b484b0c3ae6 Add comments about required includes. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	66 #include <stdbool.h>
8b484b0c3ae6 Add comments about required includes. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	67 #include "minmax.h"
8b484b0c3ae6 Add comments about required includes. Bruno Haible <bruno@clisp.org> parents: 9309 diff changeset	68 */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	69
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	70 /* Maximum value of type OFFSET. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	71 #define OFFSET_MAX \
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	72 ((((OFFSET)1 << (sizeof (OFFSET) * CHAR_BIT - 2)) - 1) * 2 + 1)
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	73
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	74 /* Default to no early abort. */
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	75 #ifndef EARLY_ABORT
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	76 # define EARLY_ABORT(ctxt) false
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	77 #endif
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	78
12336 90584cfd31a4 Add comment. Bruno Haible <bruno@clisp.org> parents: 12334 diff changeset	79 /* Use this to suppress gcc's `...may be used before initialized' warnings.
90584cfd31a4 Add comment. Bruno Haible <bruno@clisp.org> parents: 12334 diff changeset	80 Beware: The Code argument must not contain commas. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	81 #ifndef IF_LINT
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	82 # ifdef lint
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	83 # define IF_LINT(Code) Code
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	84 # else
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	85 # define IF_LINT(Code) /* empty */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	86 # endif
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	87 #endif
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	88
12334 911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	89 /* As above, but when Code must contain one comma. */
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	90 #ifndef IF_LINT2
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	91 # ifdef lint
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	92 # define IF_LINT2(Code1, Code2) Code1, Code2
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	93 # else
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	94 # define IF_LINT2(Code1, Code2) /* empty */
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	95 # endif
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	96 #endif
911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	97
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	98 /*
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	99 * Context of comparison operation.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	100 */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	101 struct context
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	102 {
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	103 #ifdef ELEMENT
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	104 /* Vectors being compared. */
9685 2858c91c7452 Avoid gcc warnings due to misplaced 'const'. Bruno Haible <bruno@clisp.org> parents: 9669 diff changeset	105 ELEMENT const *xvec;
2858c91c7452 Avoid gcc warnings due to misplaced 'const'. Bruno Haible <bruno@clisp.org> parents: 9669 diff changeset	106 ELEMENT const *yvec;
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	107 #endif
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	108
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	109 /* Extra fields. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	110 EXTRA_CONTEXT_FIELDS
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	111
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	112 /* Vector, indexed by diagonal, containing 1 + the X coordinate of the point
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	113 furthest along the given diagonal in the forward search of the edit
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	114 matrix. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	115 OFFSET *fdiag;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	116
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	117 /* Vector, indexed by diagonal, containing the X coordinate of the point
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	118 furthest along the given diagonal in the backward search of the edit
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	119 matrix. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	120 OFFSET *bdiag;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	121
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	122 #ifdef USE_HEURISTIC
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	123 /* This corresponds to the diff -H flag. With this heuristic, for
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	124 vectors with a constant small density of changes, the algorithm is
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	125 linear in the vectors size. */
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	126 bool heuristic;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	127 #endif
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	128
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	129 /* Edit scripts longer than this are too expensive to compute. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	130 OFFSET too_expensive;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	131
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	132 /* Snakes bigger than this are considered `big'. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	133 #define SNAKE_LIMIT 20
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	134 };
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	135
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	136 struct partition
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	137 {
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	138 /* Midpoints of this partition. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	139 OFFSET xmid;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	140 OFFSET ymid;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	141
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	142 /* True if low half will be analyzed minimally. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	143 bool lo_minimal;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	144
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	145 /* Likewise for high half. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	146 bool hi_minimal;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	147 };
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	148
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	149
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	150 /* Find the midpoint of the shortest edit script for a specified portion
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	151 of the two vectors.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	152
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	153 Scan from the beginnings of the vectors, and simultaneously from the ends,
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	154 doing a breadth-first search through the space of edit-sequence.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	155 When the two searches meet, we have found the midpoint of the shortest
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	156 edit sequence.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	157
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	158 If FIND_MINIMAL is true, find the minimal edit script regardless of
3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	159 expense. Otherwise, if the search is too expensive, use heuristics to
3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	160 stop the search and report a suboptimal answer.
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	161
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	162 Set PART->(xmid,ymid) to the midpoint (XMID,YMID). The diagonal number
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	163 XMID - YMID equals the number of inserted elements minus the number
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	164 of deleted elements (counting only elements before the midpoint).
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	165
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	166 Set PART->lo_minimal to true iff the minimal edit script for the
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	167 left half of the partition is known; similarly for PART->hi_minimal.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	168
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	169 This function assumes that the first elements of the specified portions
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	170 of the two vectors do not match, and likewise that the last elements do not
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	171 match. The caller must trim matching elements from the beginning and end
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	172 of the portions it is going to specify.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	173
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	174 If we return the "wrong" partitions, the worst this can do is cause
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	175 suboptimal diff output. It cannot cause incorrect diff output. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	176
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	177 static void
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	178 diag (OFFSET xoff, OFFSET xlim, OFFSET yoff, OFFSET ylim, bool find_minimal,
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	179 struct partition part, struct context ctxt)
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	180 {
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	181 OFFSET const fd = ctxt->fdiag; / Give the compiler a chance. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	182 OFFSET const bd = ctxt->bdiag; / Additional help for the compiler. */
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	183 #ifdef ELEMENT
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	184 ELEMENT const const xv = ctxt->xvec; / Still more help for the compiler. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	185 ELEMENT const const yv = ctxt->yvec; / And more and more . . . */
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	186 #define XREF_YREF_EQUAL(x,y) EQUAL (xv[x], yv[y])
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	187 #else
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	188 #define XREF_YREF_EQUAL(x,y) XVECREF_YVECREF_EQUAL (ctxt, x, y)
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	189 #endif
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	190 const OFFSET dmin = xoff - ylim; /* Minimum valid diagonal. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	191 const OFFSET dmax = xlim - yoff; /* Maximum valid diagonal. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	192 const OFFSET fmid = xoff - yoff; /* Center diagonal of top-down search. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	193 const OFFSET bmid = xlim - ylim; /* Center diagonal of bottom-up search. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	194 OFFSET fmin = fmid;
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	195 OFFSET fmax = fmid; /* Limits of top-down search. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	196 OFFSET bmin = bmid;
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	197 OFFSET bmax = bmid; /* Limits of bottom-up search. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	198 OFFSET c; /* Cost. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	199 bool odd = (fmid - bmid) & 1; /* True if southeast corner is on an odd
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	200 diagonal with respect to the northwest. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	201
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	202 fd[fmid] = xoff;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	203 bd[bmid] = xlim;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	204
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	205 for (c = 1;; ++c)
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	206 {
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	207 OFFSET d; /* Active diagonal. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	208 bool big_snake = false;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	209
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	210 /* Extend the top-down search by an edit step in each diagonal. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	211 if (fmin > dmin)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	212 fd[--fmin - 1] = -1;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	213 else
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	214 ++fmin;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	215 if (fmax < dmax)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	216 fd[++fmax + 1] = -1;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	217 else
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	218 --fmax;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	219 for (d = fmax; d >= fmin; d -= 2)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	220 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	221 OFFSET x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	222 OFFSET y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	223 OFFSET tlo = fd[d - 1];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	224 OFFSET thi = fd[d + 1];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	225 OFFSET x0 = tlo < thi ? thi : tlo + 1;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	226
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	227 for (x = x0, y = x0 - d;
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	228 x < xlim && y < ylim && XREF_YREF_EQUAL (x, y);
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	229 x++, y++)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	230 continue;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	231 if (x - x0 > SNAKE_LIMIT)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	232 big_snake = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	233 fd[d] = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	234 if (odd && bmin <= d && d <= bmax && bd[d] <= x)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	235 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	236 part->xmid = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	237 part->ymid = y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	238 part->lo_minimal = part->hi_minimal = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	239 return;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	240 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	241 }
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	242
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	243 /* Similarly extend the bottom-up search. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	244 if (bmin > dmin)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	245 bd[--bmin - 1] = OFFSET_MAX;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	246 else
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	247 ++bmin;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	248 if (bmax < dmax)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	249 bd[++bmax + 1] = OFFSET_MAX;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	250 else
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	251 --bmax;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	252 for (d = bmax; d >= bmin; d -= 2)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	253 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	254 OFFSET x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	255 OFFSET y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	256 OFFSET tlo = bd[d - 1];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	257 OFFSET thi = bd[d + 1];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	258 OFFSET x0 = tlo < thi ? tlo : thi - 1;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	259
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	260 for (x = x0, y = x0 - d;
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	261 xoff < x && yoff < y && XREF_YREF_EQUAL (x - 1, y - 1);
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	262 x--, y--)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	263 continue;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	264 if (x0 - x > SNAKE_LIMIT)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	265 big_snake = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	266 bd[d] = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	267 if (!odd && fmin <= d && d <= fmax && x <= fd[d])
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	268 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	269 part->xmid = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	270 part->ymid = y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	271 part->lo_minimal = part->hi_minimal = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	272 return;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	273 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	274 }
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	275
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	276 if (find_minimal)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	277 continue;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	278
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	279 #ifdef USE_HEURISTIC
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	280 /* Heuristic: check occasionally for a diagonal that has made lots
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	281 of progress compared with the edit distance. If we have any
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	282 such, find the one that has made the most progress and return it
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	283 as if it had succeeded.
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	284
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	285 With this heuristic, for vectors with a constant small density
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	286 of changes, the algorithm is linear in the vector size. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	287
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	288 if (200 < c && big_snake && ctxt->heuristic)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	289 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	290 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	291 OFFSET best = 0;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	292
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	293 for (d = fmax; d >= fmin; d -= 2)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	294 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	295 OFFSET dd = d - fmid;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	296 OFFSET x = fd[d];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	297 OFFSET y = x - d;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	298 OFFSET v = (x - xoff) * 2 - dd;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	299
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	300 if (v > 12 * (c + (dd < 0 ? -dd : dd)))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	301 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	302 if (v > best
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	303 && xoff + SNAKE_LIMIT <= x && x < xlim
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	304 && yoff + SNAKE_LIMIT <= y && y < ylim)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	305 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	306 /* We have a good enough best diagonal; now insist
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	307 that it end with a significant snake. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	308 int k;
12331 dfb465b19291 diffseq: reduce scope of variable 'best'. Bruno Haible <bruno@clisp.org> parents: 12330 diff changeset	309
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	310 for (k = 1; XREF_YREF_EQUAL (x - k, y - k); k++)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	311 if (k == SNAKE_LIMIT)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	312 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	313 best = v;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	314 part->xmid = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	315 part->ymid = y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	316 break;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	317 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	318 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	319 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	320 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	321 if (best > 0)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	322 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	323 part->lo_minimal = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	324 part->hi_minimal = false;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	325 return;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	326 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	327 }
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	328
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	329 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	330 OFFSET best = 0;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	331
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	332 for (d = bmax; d >= bmin; d -= 2)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	333 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	334 OFFSET dd = d - bmid;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	335 OFFSET x = bd[d];
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	336 OFFSET y = x - d;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	337 OFFSET v = (xlim - x) * 2 + dd;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	338
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	339 if (v > 12 * (c + (dd < 0 ? -dd : dd)))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	340 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	341 if (v > best
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	342 && xoff < x && x <= xlim - SNAKE_LIMIT
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	343 && yoff < y && y <= ylim - SNAKE_LIMIT)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	344 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	345 /* We have a good enough best diagonal; now insist
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	346 that it end with a significant snake. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	347 int k;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	348
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	349 for (k = 0; XREF_YREF_EQUAL (x + k, y + k); k++)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	350 if (k == SNAKE_LIMIT - 1)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	351 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	352 best = v;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	353 part->xmid = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	354 part->ymid = y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	355 break;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	356 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	357 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	358 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	359 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	360 if (best > 0)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	361 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	362 part->lo_minimal = false;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	363 part->hi_minimal = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	364 return;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	365 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	366 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	367 }
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	368 #endif /* USE_HEURISTIC */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	369
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	370 /* Heuristic: if we've gone well beyond the call of duty, give up
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	371 and report halfway between our best results so far. */
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	372 if (c >= ctxt->too_expensive)
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	373 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	374 OFFSET fxybest;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	375 OFFSET fxbest IF_LINT (= 0);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	376 OFFSET bxybest;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	377 OFFSET bxbest IF_LINT (= 0);
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	378
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	379 /* Find forward diagonal that maximizes X + Y. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	380 fxybest = -1;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	381 for (d = fmax; d >= fmin; d -= 2)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	382 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	383 OFFSET x = MIN (fd[d], xlim);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	384 OFFSET y = x - d;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	385 if (ylim < y)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	386 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	387 x = ylim + d;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	388 y = ylim;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	389 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	390 if (fxybest < x + y)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	391 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	392 fxybest = x + y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	393 fxbest = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	394 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	395 }
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	396
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	397 /* Find backward diagonal that minimizes X + Y. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	398 bxybest = OFFSET_MAX;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	399 for (d = bmax; d >= bmin; d -= 2)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	400 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	401 OFFSET x = MAX (xoff, bd[d]);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	402 OFFSET y = x - d;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	403 if (y < yoff)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	404 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	405 x = yoff + d;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	406 y = yoff;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	407 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	408 if (x + y < bxybest)
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	409 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	410 bxybest = x + y;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	411 bxbest = x;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	412 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	413 }
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	414
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	415 /* Use the better of the two diagonals. */
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	416 if ((xlim + ylim) - bxybest < fxybest - (xoff + yoff))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	417 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	418 part->xmid = fxbest;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	419 part->ymid = fxybest - fxbest;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	420 part->lo_minimal = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	421 part->hi_minimal = false;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	422 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	423 else
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	424 {
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	425 part->xmid = bxbest;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	426 part->ymid = bxybest - bxbest;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	427 part->lo_minimal = false;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	428 part->hi_minimal = true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	429 }
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	430 return;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	431 }
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	432 }
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	433 #undef XREF_YREF_EQUAL
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	434 }
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	435
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	436
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	437 /* Compare in detail contiguous subsequences of the two vectors
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	438 which are known, as a whole, to match each other.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	439
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	440 The subsequence of vector 0 is [XOFF, XLIM) and likewise for vector 1.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	441
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	442 Note that XLIM, YLIM are exclusive bounds. All indices into the vectors
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	443 are origin-0.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	444
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	445 If FIND_MINIMAL, find a minimal difference no matter how
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	446 expensive it is.
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	447
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	448 The results are recorded by invoking NOTE_DELETE and NOTE_INSERT.
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	449
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	450 Return false if terminated normally, or true if terminated through early
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	451 abort. */
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	452
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	453 static bool
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	454 compareseq (OFFSET xoff, OFFSET xlim, OFFSET yoff, OFFSET ylim,
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	455 bool find_minimal, struct context *ctxt)
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	456 {
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	457 #ifdef ELEMENT
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	458 ELEMENT const xv = ctxt->xvec; / Help the compiler. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	459 ELEMENT const *yv = ctxt->yvec;
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	460 #define XREF_YREF_EQUAL(x,y) EQUAL (xv[x], yv[y])
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	461 #else
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	462 #define XREF_YREF_EQUAL(x,y) XVECREF_YVECREF_EQUAL (ctxt, x, y)
97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	463 #endif
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	464
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	465 /* Slide down the bottom initial diagonal. */
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	466 while (xoff < xlim && yoff < ylim && XREF_YREF_EQUAL (xoff, yoff))
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	467 {
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	468 xoff++;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	469 yoff++;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	470 }
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	471
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	472 /* Slide up the top initial diagonal. */
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	473 while (xoff < xlim && yoff < ylim && XREF_YREF_EQUAL (xlim - 1, ylim - 1))
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	474 {
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	475 xlim--;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	476 ylim--;
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	477 }
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	478
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	479 /* Handle simple cases. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	480 if (xoff == xlim)
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	481 while (yoff < ylim)
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	482 {
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	483 NOTE_INSERT (ctxt, yoff);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	484 if (EARLY_ABORT (ctxt))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	485 return true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	486 yoff++;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	487 }
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	488 else if (yoff == ylim)
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	489 while (xoff < xlim)
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	490 {
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	491 NOTE_DELETE (ctxt, xoff);
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	492 if (EARLY_ABORT (ctxt))
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	493 return true;
e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	494 xoff++;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	495 }
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	496 else
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	497 {
12334 911f28ebb9c4 diffseq: avoid spurious gcc warnings Jim Meyering <meyering@redhat.com> parents: 12331 diff changeset	498 struct partition part IF_LINT2 (= { .xmid = 0, .ymid = 0 });
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	499
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	500 /* Find a point of correspondence in the middle of the vectors. */
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	501 diag (xoff, xlim, yoff, ylim, find_minimal, &part, ctxt);
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	502
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	503 /* Use the partitions to split this problem into subproblems. */
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	504 if (compareseq (xoff, part.xmid, yoff, part.ymid, part.lo_minimal, ctxt))
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	505 return true;
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	506 if (compareseq (part.xmid, xlim, part.ymid, ylim, part.hi_minimal, ctxt))
12421 e8d2c6fc33ad Use spaces for indentation, not tabs. Bruno Haible <bruno@clisp.org> parents: 12336 diff changeset	507 return true;
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	508 }
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	509
74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	510 return false;
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	511 #undef XREF_YREF_EQUAL
9147 d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	512 }
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	513
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	514 #undef ELEMENT
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	515 #undef EQUAL
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	516 #undef OFFSET
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	517 #undef EXTRA_CONTEXT_FIELDS
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	518 #undef NOTE_DELETE
d5c437e55b50 * MODULES.html.sh: Add diffseq. Paul Eggert <eggert@cs.ucla.edu> parents: diff changeset	519 #undef NOTE_INSERT
10436 74c36e9e4884 Add an "early abort" facility to diffseq. Ralf Wildenhues <Ralf.Wildenhues@gmx.de> parents: 9685 diff changeset	520 #undef EARLY_ABORT
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	521 #undef USE_HEURISTIC
13243 97c81b93ec7c diffseq: Accommodate use-case with abstract arrays. Bruno Haible <bruno@clisp.org> parents: 12559 diff changeset	522 #undef XVECREF_YVECREF_EQUAL
9149 3d5b34d43010 - Comment style. Bruno Haible <bruno@clisp.org> parents: 9147 diff changeset	523 #undef OFFSET_MAX

Mercurial > hg > octave-kai > gnulib-hg

annotate lib/diffseq.h @ 13243:97c81b93ec7c