git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v3 3/4] word diff: make regex configurable via attributes

From
Thomas Rast <trast@student.ethz.ch>
Date
Jan 11, 2009, 10:27 UTC
Message-ID
<72242bd75fa8d55c2afc723f8539ef56f2569d3e.1231669012.git.trast@student.ethz.ch>
In-Reply-To
<529cd830908f018f796dbc46d3b055c1f8ba9c1b.1231669012.git.trast@student.ethz.ch>

Make the --color-words splitting regular expression configurable via the diff driver's 'wordregex' attribute. The user can then set the driver on a file in .gitattributes. If a regex is given on the command line, it overrides the driver's setting.

We also provide built-in regexes for some of the languages that already had funcname patterns. (They are designed to run UTF-8 sequences into a single chunk to make sure they remain readable.)

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
---
 Documentation/diff-options.txt  |    4 +++-
 Documentation/gitattributes.txt |   21 +++++++++++++++++++++
 diff.c                          |   10 ++++++++++
 userdiff.c                      |   27 +++++++++++++++++++--------
 userdiff.h                      |    1 +
 5 files changed, 54 insertions(+), 9 deletions(-)
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 6152d5b..d22c06b 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -96,7 +96,9 @@ endif::git-format-patch[]
 	By default, a new word only starts at whitespace, so that a
 	'word' is defined as a maximal sequence of non-whitespace
 	characters.  The optional argument <regex> can be used to
-	configure this.
+	configure this.  It can also be set via a diff driver, see
+	linkgit:gitattributes[1]; if a <regex> is given explicitly, it
+	overrides any diff driver setting.
 +
 The <regex> must be an (extended) regular expression.  When set, every
 non-overlapping match of the <regex> is considered a word.  (Regular
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 8af22ec..67f5522 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -334,6 +334,27 @@ patterns are available:
 - `tex` suitable for source code for LaTeX documents.
 
 
+Customizing word diff
+^^^^^^^^^^^^^^^^^^^^^
+
+You can customize the rules that `git diff --color-words` uses to
+split words in a line, by specifying an appropriate regular expression
+in the "diff.*.wordregex" configuration variable.  For example, in TeX
+a backslash followed by a sequence of letters forms a command, but
+several such commands can be run together without intervening
+whitespace.  To separate them, use a regular expression such as
+
+------------------------
+[diff "tex"]
+	wordregex = "\\\\[a-zA-Z]+|[{}]|\\\\.|[^\\{} \t]+"
+------------------------
+
+Similar to 'xfuncname', a built in value is provided for the drivers
+`bibtex`, `html`, `java`, `php`, `python` and `tex`.  See the
+documentation of --color-words in linkgit:git-diff[1] for the precise
+semantics.
+
+
 Performing text diffs of binary files
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/diff.c b/diff.c
index badaea6..c1cc426 100644
--- a/diff.c
+++ b/diff.c
@@ -1548,6 +1548,12 @@ static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespe
 	return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
 }
 
+static const char *userdiff_word_regex(struct diff_filespec *one)
+{
+	diff_filespec_load_driver(one);
+	return one->driver->word_regex;
+}
+
 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
 {
 	if (!options->a_prefix)
@@ -1708,6 +1714,10 @@ static void builtin_diff(const char *name_a,
 			ecbdata.diff_words =
 				xcalloc(1, sizeof(struct diff_words_data));
 			ecbdata.diff_words->file = o->file;
+			if (!o->word_regex)
+				o->word_regex = userdiff_word_regex(one);
+			if (!o->word_regex)
+				o->word_regex = userdiff_word_regex(two);
 			if (o->word_regex) {
 				ecbdata.diff_words->word_regex = (regex_t *)
 					xmalloc(sizeof(regex_t));
diff --git a/userdiff.c b/userdiff.c
index 3681062..7fd9a07 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -6,13 +6,17 @@ static struct userdiff_driver *drivers;
 static int ndrivers;
 static int drivers_alloc;
 
-#define FUNCNAME(name, pattern) \
+#define FUNCNAME(name, pattern)			\
 	{ name, NULL, -1, { pattern, REG_EXTENDED } }
+#define PATTERNS(name, pattern, wordregex)			\
+	{ name, NULL, -1, { pattern, REG_EXTENDED }, NULL, wordregex }
 static struct userdiff_driver builtin_drivers[] = {
-FUNCNAME("html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$"),
-FUNCNAME("java",
+PATTERNS("html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$",
+	 "[^<>= \t]+|\\S"),
+PATTERNS("java",
 	 "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
-	 "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$"),
+	 "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$",
+	 "[a-zA-Z_][a-zA-Z0-9_]*|[-+0-9.e]+|[-+*/]=|\\+\\+|--|\\S|[\x80-\xff]+"),
 FUNCNAME("objc",
 	 /* Negate C statements that can look like functions */
 	 "!^[ \t]*(do|for|if|else|return|switch|while)\n"
@@ -27,14 +31,19 @@ FUNCNAME("pascal",
 		"implementation|initialization|finalization)[ \t]*.*)$"
 	 "\n"
 	 "^(.*=[ \t]*(class|record).*)$"),
-FUNCNAME("php", "^[\t ]*((function|class).*)"),
-FUNCNAME("python", "^[ \t]*((class|def)[ \t].*)$"),
+PATTERNS("php", "^[\t ]*((function|class).*)",
+	 "\\$?[a-zA-Z_][a-zA-Z0-9_]*|[-+0-9.e]+|[-+*/]=|\\+\\+|--|->|\\S|[\x80-\xff]+"),
+PATTERNS("python", "^[ \t]*((class|def)[ \t].*)$",
+	 "[a-zA-Z_][a-zA-Z0-9_]*|[-+0-9.e]+|[-+*/]=|//|\\S|[\x80-\xff]+"),
 FUNCNAME("ruby", "^[ \t]*((class|module|def)[ \t].*)$"),
-FUNCNAME("bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$"),
-FUNCNAME("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$"),
+PATTERNS("bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
+	 "[={}\"]|[^={}\" \t]+"),
+PATTERNS("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
+	 "\\\\[a-zA-Z@]+|[{}]|\\\\.|[^\\{} \t]+"),
 { "default", NULL, -1, { NULL, 0 } },
 };
 #undef FUNCNAME
+#undef PATTERNS
 
 static struct userdiff_driver driver_true = {
 	"diff=true",
@@ -134,6 +143,8 @@ int userdiff_config(const char *k, const char *v)
 		return parse_string(&drv->external, k, v);
 	if ((drv = parse_driver(k, v, "textconv")))
 		return parse_string(&drv->textconv, k, v);
+	if ((drv = parse_driver(k, v, "wordregex")))
+		return parse_string(&drv->word_regex, k, v);
 
 	return 0;
 }
diff --git a/userdiff.h b/userdiff.h
index ba29457..2aab13e 100644
--- a/userdiff.h
+++ b/userdiff.h
@@ -12,6 +12,7 @@ struct userdiff_driver {
 	int binary;
 	struct userdiff_funcname funcname;
 	const char *textconv;
+	const char *word_regex;
 };
 
 int userdiff_config(const char *k, const char *v);

-- 
1.6.1.269.g0769
Previous: Thomas RastNext: Thomas Rast
Message 25 of 34 in “make diff --color-words customizable”
  1. make diff --color-words customizableThomas Rast, Jan 9, 2009
  2. Johannes SchindelinJan 9, 2009
  3. Thomas RastJan 9, 2009
  4. Johannes SchindelinJan 9, 2009
  5. color-words: take an optional regular expression describing wordsJohannes Schindelin, Jan 9, 2009
  6. Thomas RastJan 9, 2009
  7. Teemu LikonenJan 9, 2009
  8. make diff --color-words customizableThomas Rast, Jan 10, 2009
  9. Jakub NarebskiJan 10, 2009
  10. Johannes SchindelinJan 10, 2009
  11. Jakub NarebskiJan 10, 2009
  12. Johannes SchindelinJan 10, 2009
  13. Jakub NarebskiJan 12, 2009
  14. Johannes SchindelinJan 13, 2009
  15. Davide LibenziJan 10, 2009
  16. Jakub NarebskiJan 13, 2009
  17. Davide LibenziJan 13, 2009
  18. Johannes SchindelinJan 10, 2009
  19. Thomas RastJan 10, 2009
  20. Johannes SchindelinJan 10, 2009
  21. Junio C HamanoJan 11, 2009
  22. 0/4 customizable --color-wordsThomas Rast, Jan 11, 2009
  23. 1/4 word diff: comments, preparations for regex customizationThomas Rast, Jan 11, 2009
  24. 2/4 word diff: customizable word splitsThomas Rast, Jan 11, 2009
  25. 3/4 word diff: make regex configurable via attributesThomas Rast, Jan 11, 2009
  26. 4/4 word diff: test customizable word splitsThomas Rast, Jan 11, 2009
  27. Junio C HamanoJan 11, 2009
  28. Junio C HamanoJan 11, 2009
  29. Johannes SchindelinJan 11, 2009
  30. Johannes SchindelinJan 11, 2009
  31. Junio C HamanoJan 11, 2009
  32. Jeff KingJan 9, 2009
  33. Johannes SchindelinJan 9, 2009
  34. Jeff KingJan 9, 2009

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.