[PATCH v2 0/7] string_list_split*() updates
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jul 31, 2025, 22:45 UTC
- Message-ID
- <20250731224607.3942417-1-gitster@pobox.com>
- In-Reply-To
- <20250731063949.1601669-1-gitster@pobox.com>
Two related string-list API functions, string_list_split() and string_list_split_in_place(), more or less duplicates their implementations. They both take a single string, and split the string at the delimiter and stuff the result into a string list.
However, there is one subtle and unnecessary difference. The non "in-place" variant only allows a single byte value as delimiter, while the "in-place" variant can take multiple delimiters (e.g., "split at either a comma or a space").
This series first updates the string_list_split() to allow multiple delimiters like string_list_split_in_place() does, by unifying their implementations into one. This refactoring allows us to give new features to these two functions more easily.
Then these functions learn to optionally
- trim the split string pieces before placing them in the resulting string list.
- omit empty string pieces from the resulting string list.
An existing caller of string_list_split() in diff.c trims the elements in the resulting string list before it uses them, which is simplified by taking advantage of this new feature.
A handful of code paths call string_list_split*(), immediately followed by string_list_remove_empty_items(). They are simplified by not placing empty items in the list in the first place.
Junio C Hamano (7):
string-list: report programming error with BUG
string-list: align string_list_split() with its _in_place()
counterpart
string-list: unify string_list_split* functions
string-list: optionally trim string pieces split by
string_list_split*()
diff: simplify parsing of diff.colormovedws
string-list: optionally omit empty string pieces in
string_list_split*()
string-list: split-then-remove-empty can be done while splittingbuiltin/blame.c | 2 +- builtin/merge.c | 2 +- builtin/var.c | 2 +- connect.c | 2 +- diff.c | 20 ++---- fetch-pack.c | 2 +- notes.c | 6 +- parse-options.c | 2 +- pathspec.c | 3 +- protocol.c | 2 +- ref-filter.c | 4 +- setup.c | 3 +- string-list.c | 120 ++++++++++++++++++++++++----------- string-list.h | 29 ++++++--- t/helper/test-hashmap.c | 4 +- t/helper/test-json-writer.c | 4 +- t/helper/test-path-utils.c | 3 +- t/helper/test-ref-store.c | 2 +- t/unit-tests/u-string-list.c | 95 ++++++++++++++++++++++++--- transport.c | 2 +- upload-pack.c | 2 +- 21 files changed, 221 insertions(+), 90 deletions(-)
1: e56dc89249 ! 1: 1c2b222eec string-list: report programming error with BUG
@@ Commit message
string-list: report programming error with BUG
Passing a string list that has .strdup_strings bit unset to
- string_list_split(), orone that has .strdup_strings bit set to
+ string_list_split(), or one that has .strdup_strings bit set to
string_list_split_in_place(), is a programmer error. Do not use
die() to abort the execution. Use BUG() instead.
2: 1bd3506fad ! 2: a7e07b94ef string-list: align string_list_split() with its _in_place() counterpart
@@ Commit message
For some unknown reason, unlike string_list_split_in_place(),
string_list_split() took only a single character as a field
delimiter. Before giving both functions more features in future
- commits, allow stirng_list_split() to take more than one delimiter
+ commits, allow string_list_split() to take more than one delimiter
characters to make them closer to each other.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
3: 52c3b694d2 ! 3: b7a7fbb975 string-list: unify string_list_split* functions
@@ string-list.c: void unsorted_string_list_delete_item(struct string_list *list, i
-int string_list_split(struct string_list *list, const char *string,
- const char *delim, int maxsplit)
-+static void append_one(struct string_list *list,
-+ const char *p, const char *end,
-+ int in_place)
++/*
++ * append a substring [p..end] to list; return number of things it
++ * appended to the list.
++ */
++static int append_one(struct string_list *list,
++ const char *p, const char *end,
++ int in_place)
+{
+ if (!end)
+ end = p + strlen(p);
@@ string-list.c: void unsorted_string_list_delete_item(struct string_list *list, i
+ } else {
+ string_list_append_nodup(list, xmemdupz(p, end - p));
+ }
++ return 1;
+}
+
+/*
@@ string-list.c: void unsorted_string_list_delete_item(struct string_list *list, i
- BUG("internal error in string_list_split(): "
- "list->strdup_strings must be set");
for (;;) {
-+ char *end;
-+
- count++;
+- count++;
- if (maxsplit >= 0 && count > maxsplit) {
- string_list_append(list, p);
- return count;
@@ string-list.c: void unsorted_string_list_delete_item(struct string_list *list, i
- p = end + 1;
- } else {
- string_list_append(list, p);
-+ if (maxsplit >= 0 && count > maxsplit)
++ char *end;
++
++ if (0 <= maxsplit && maxsplit <= count)
+ end = NULL;
+ else
+ end = strpbrk(p, delim);
+
-+ append_one(list, p, end, in_place);
++ count += append_one(list, p, end, in_place);
+
+ if (!end)
return count;
4: 13e3d9fbaf ! 4: c566d88c28 string-list: optionally trim string pieces split by string_list_split()
@@ Metadata
Author: Junio C Hamano <gitster@pobox.com>
## Commit message ##
- string-list: optionally trim string pieces split by string_list_split()
+ string-list: optionally trim string pieces split by string_list_split*()
Teach the unified split_string() to take an optional "flags" word,
and define the first flag STRING_LIST_SPLIT_TRIM to cause the split
@@ Commit message
## string-list.c ##
@@ string-list.c: void unsorted_string_list_delete_item(struct string_list *list, int i, int free_
-
- static void append_one(struct string_list *list,
- const char *p, const char *end,
-- int in_place)
-+ int in_place, unsigned flags)
+ */
+ static int append_one(struct string_list *list,
+ const char *p, const char *end,
+- int in_place)
++ int in_place, unsigned flags)
{
if (!end)
end = p + strlen(p);
@@ string-list.c: void unsorted_string_list_delete_item(struct string_list *list, i
if (in_place) {
*((char *)end) = '\0';
string_list_append(list, p);
-@@ string-list.c: static void append_one(struct string_list *list,
+@@ string-list.c: static int append_one(struct string_list *list,
* returns "char *" pointer into that const string. Yucky but works ;-).
*/
static int split_string(struct string_list *list, const char *string, const char *delim,
@@ string-list.c: static int split_string(struct string_list *list, const char *str
+ p++;
+ }
+
- count++;
- if (maxsplit >= 0 && count > maxsplit)
+ if (0 <= maxsplit && maxsplit <= count)
end = NULL;
else
end = strpbrk(p, delim);
-- append_one(list, p, end, in_place);
-+ append_one(list, p, end, in_place, flags);
+- count += append_one(list, p, end, in_place);
++ count += append_one(list, p, end, in_place, flags);
if (!end)
return count;
5: 912c6ee193 ! 5: eb272e0f22 diff: simplify parsing of diff.colormovedws
@@ Commit message
The code to parse this configuration variable, whose value is a
comma separated known tokens like "ignore-space-change" and
- "ignore-all-space", uses string_list_split() to split the value int
+ "ignore-all-space", uses string_list_split() to split the value into
pieces, and then places each piece of string in a strbuf to trim,
before comparing the result with the list of known tokens.
- Thanks to the previous steps, now string_list_split() knows to trim
- the resulting pieces in the string list. Use it to simplify the
- code.
+ Thanks to the previous steps, now string_list_split() can trim the
+ resulting pieces before it places them in the string list. Use it
+ to simplify the code.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
-: ---------- > 6: d418078a84 string-list: optionally omit empty string pieces in string_list_split*()
-: ---------- > 7: 12c1189a08 string-list: split-then-remove-empty can be done while splitting