Rename path_list to string_list

The name path_list was correct for the first usage of that data structure,
but it really is a general-purpose string list.

$ perl -i -pe 's/path-list/string-list/g' $(git grep -l path-list)
$ perl -i -pe 's/path_list/string_list/g' $(git grep -l path_list)
$ git mv path-list.h string-list.h
$ git mv path-list.c string-list.c
$ perl -i -pe 's/has_path/has_string/g' $(git grep -l has_path)
$ perl -i -pe 's/path/string/g' string-list.[ch]
$ git mv Documentation/technical/api-path-list.txt \
	Documentation/technical/api-string-list.txt
$ perl -i -pe 's/strdup_paths/strdup_strings/g' $(git grep -l strdup_paths)

... and then fix all users of string-list to access the member "string"
instead of "path".

Documentation/technical/api-string-list.txt needed some rewrapping, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/CodingGuidelines

@@ -105,7 +105,7 @@ For C programs:
 
  - Use the API.  No, really.  We have a strbuf (variable length
    string), several arrays with the ALLOC_GROW() macro, a
-   path_list for sorted string lists, a hash map (mapping struct
+   string_list for sorted string lists, a hash map (mapping struct
    objects) named "struct decorate", amongst other things.
 
  - When you come up with an API, document it.

Documentation/technical/api-string-list.txt

@@ -0,0 +1,128 @@
+string-list API
+===============
+
+The string_list API offers a data structure and functions to handle sorted
+and unsorted string lists.
+
+The 'string_list' struct used to be called 'path_list', but was renamed
+because it is not specific to paths.
+
+The caller:
+
+. Allocates and clears a `struct string_list` variable.
+
+. Initializes the members. You might want to set the flag `strdup_strings`
+  if the strings should be strdup()ed. For example, this is necessary
+  when you add something like git_path("..."), since that function returns
+  a static buffer that will change with the next call to git_path().
++
+If you need something advanced, you can manually malloc() the `items`
+member (you need this if you add things later) and you should set the
+`nr` and `alloc` members in that case, too.
+
+. Adds new items to the list, using `string_list_append` or
+  `string_list_insert`.
+
+. Can check if a string is in the list using `string_list_has_string` or
+  `unsorted_string_list_has_string` and get it from the list using
+  `string_list_lookup` for sorted lists.
+
+. Can sort an unsorted list using `sort_string_list`.
+
+. Finally it should free the list using `string_list_clear`.
+
+Example:
+
+----
+struct string_list list;
+int i;
+
+memset(&list, 0, sizeof(struct string_list));
+string_list_append("foo", &list);
+string_list_append("bar", &list);
+for (i = 0; i < list.nr; i++)
+	printf("%s\n", list.items[i].path)
+----
+
+NOTE: It is more efficient to build an unsorted list and sort it
+afterwards, instead of building a sorted list (`O(n log n)` instead of
+`O(n^2)`).
++
+However, if you use the list to check if a certain string was added
+already, you should not do that (using unsorted_string_list_has_string()),
+because the complexity would be quadratic again (but with a worse factor).
+
+Functions
+---------
+
+* General ones (works with sorted and unsorted lists as well)
+
+`print_string_list`::
+
+	Dump a string_list to stdout, useful mainly for debugging purposes. It
+	can take an optional header argument and it writes out the
+	string-pointer pairs of the string_list, each one in its own line.
+
+`string_list_clear`::
+
+	Free a string_list. The `string` pointer of the items will be freed in
+	case the `strdup_strings` member of the string_list is set. The second
+	parameter controls if the `util` pointer of the items should be freed
+	or not.
+
+* Functions for sorted lists only
+
+`string_list_has_string`::
+
+	Determine if the string_list has a given string or not.
+
+`string_list_insert`::
+
+	Insert a new element to the string_list. The returned pointer can be
+	handy if you want to write something to the `util` pointer of the
+	string_list_item containing the just added string.
++
+Since this function uses xrealloc() (which die()s if it fails) if the
+list needs to grow, it is safe not to check the pointer. I.e. you may
+write `string_list_insert(...)->util = ...;`.
+
+`string_list_lookup`::
+
+	Look up a given string in the string_list, returning the containing
+	string_list_item. If the string is not found, NULL is returned.
+
+* Functions for unsorted lists only
+
+`string_list_append`::
+
+	Append a new string to the end of the string_list.
+
+`sort_string_list`::
+
+	Make an unsorted list sorted.
+
+`unsorted_string_list_has_string`::
+
+	It's like `string_list_has_string()` but for unsorted lists.
++
+This function needs to look through all items, as opposed to its
+counterpart for sorted lists, which performs a binary search.
+
+Data structures
+---------------
+
+* `struct string_list_item`
+
+Represents an item of the list. The `path` member is a pointer to the
+string, and you may use the `util` member for any purpose, if you want.
+
+* `struct string_list`
+
+Represents the list itself.
+
+. The array of items are available via the `items` member.
+. The `nr` member contains the number of items stored in the list.
+. The `alloc` member is used to avoid reallocating at every insertion.
+  You should not tamper with it.
+. Setting the `strdup_strings` member to 1 will strdup() the strings
+  before adding them, see above.

Makefile

@@ -356,7 +356,7 @@ LIB_H += pack-refs.h
 LIB_H += pack-revindex.h
 LIB_H += parse-options.h
 LIB_H += patch-ids.h
-LIB_H += path-list.h
+LIB_H += string-list.h
 LIB_H += pkt-line.h
 LIB_H += progress.h
 LIB_H += quote.h
@@ -437,7 +437,7 @@ LIB_OBJS += pager.o
 LIB_OBJS += parse-options.o
 LIB_OBJS += patch-delta.o
 LIB_OBJS += patch-ids.o
-LIB_OBJS += path-list.o
+LIB_OBJS += string-list.o
 LIB_OBJS += path.o
 LIB_OBJS += pkt-line.o
 LIB_OBJS += pretty.o

builtin-apply.c

@@ -12,7 +12,7 @@
 #include "blob.h"
 #include "delta.h"
 #include "builtin.h"
-#include "path-list.h"
+#include "string-list.h"
 
 /*
  *  --check turns on checking that the working tree matches the
@@ -194,7 +194,7 @@ struct image {
  * the case where more than one patches touch the same file.
  */
 
-static struct path_list fn_table;
+static struct string_list fn_table;
 
 static uint32_t hash_line(const char *cp, size_t len)
 {
@@ -2250,12 +2250,12 @@ static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
 
 static struct patch *in_fn_table(const char *name)
 {
-	struct path_list_item *item;
+	struct string_list_item *item;
 
 	if (name == NULL)
 		return NULL;
 
-	item = path_list_lookup(name, &fn_table);
+	item = string_list_lookup(name, &fn_table);
 	if (item != NULL)
 		return (struct patch *)item->util;
 
@@ -2264,15 +2264,15 @@ static struct patch *in_fn_table(const char *name)
 
 static void add_to_fn_table(struct patch *patch)
 {
-	struct path_list_item *item;
+	struct string_list_item *item;
 
 	/*
 	 * Always add new_name unless patch is a deletion
 	 * This should cover the cases for normal diffs,
 	 * file creations and copies
 	 */
 	if (patch->new_name != NULL) {
-		item = path_list_insert(patch->new_name, &fn_table);
+		item = string_list_insert(patch->new_name, &fn_table);
 		item->util = patch;
 	}
 
@@ -2281,7 +2281,7 @@ static void add_to_fn_table(struct patch *patch)
 	 * later chunks shouldn't patch old names
 	 */
 	if ((patch->new_name == NULL) || (patch->is_rename)) {
-		item = path_list_insert(patch->old_name, &fn_table);
+		item = string_list_insert(patch->old_name, &fn_table);
 		item->util = (struct patch *) -1;
 	}
 }
@@ -3051,7 +3051,7 @@ static int apply_patch(int fd, const char *filename, int options)
 	int skipped_patch = 0;
 
 	/* FIXME - memory leak when using multiple patch files as inputs */
-	memset(&fn_table, 0, sizeof(struct path_list));
+	memset(&fn_table, 0, sizeof(struct string_list));
 	strbuf_init(&buf, 0);
 	patch_input_file = filename;
 	read_patch_file(&buf, fd);

builtin-blame.c

@@ -16,7 +16,7 @@
 #include "quote.h"
 #include "xdiff-interface.h"
 #include "cache-tree.h"
-#include "path-list.h"
+#include "string-list.h"
 #include "mailmap.h"
 #include "parse-options.h"
 
@@ -40,7 +40,7 @@ static int blank_boundary;
 static int incremental;
 static int cmd_is_annotate;
 static int xdl_opts = XDF_NEED_MINIMAL;
-static struct path_list mailmap;
+static struct string_list mailmap;
 
 #ifndef DEBUG
 #define DEBUG 0
@@ -1926,7 +1926,7 @@ static void sanity_check_refcnt(struct scoreboard *sb)
  * Used for the command line parsing; check if the path exists
  * in the working tree.
  */
-static int has_path_in_work_tree(const char *path)
+static int has_string_in_work_tree(const char *path)
 {
 	struct stat st;
 	return !lstat(path, &st);
@@ -2390,14 +2390,14 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 		if (argc < 2)
 			usage_with_options(blame_opt_usage, options);
 		path = add_prefix(prefix, argv[argc - 1]);
-		if (argc == 3 && !has_path_in_work_tree(path)) { /* (2b) */
+		if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */
 			path = add_prefix(prefix, argv[1]);
 			argv[1] = argv[2];
 		}
 		argv[argc - 1] = "--";
 
 		setup_work_tree();
-		if (!has_path_in_work_tree(path))
+		if (!has_string_in_work_tree(path))
 			die("cannot stat path %s: %s", path, strerror(errno));
 	}