Add sort --unique

doc_src/cmds/path.rst

@@ -21,7 +21,7 @@ Synopsis
     path resolve GENERAL_OPTIONS [PATH...]
     path change-extension GENERAL_OPTIONS EXTENSION [PATH...]
     path sort GENERAL_OPTIONS [(-v | --invert)] \
-        [--what=basename|dirname|path] [([PATH...]
+        [-u | --unique] [--what=basename|dirname|path] [([PATH...]
 
     GENERAL_OPTIONS := [(-z | --null-in)] [(-Z | --null-out)] [(-q | --quiet)]
 
@@ -351,6 +351,8 @@ With ``--invert`` or ``-v`` the sort is reversed.
 
 With ``--what=`` only the given path of the path is compared, e.g. ``--what=dirname`` causes only the dirname to be compared, ``--what=basename`` only the basename and ``--what=path`` causes the entire path to be compared (this is the default).
 
+With ``--unique`` or ``-u`` the sort is deduplicated, meaning only the first of a run that have the same key is kept. So if you are sorting by basename, then only the first of each basename is used.
+
 The sort used is stable, so sorting first by basename and then by dirname works and causes the files to be grouped according to directory.
 
 It currently returns 0 if it was given any paths.
@@ -368,6 +370,10 @@ Examples
    10-foo
    2-bar
 
+   >_ path sort --unique --what=basename $fish_function_path/*.fish
+   # prints a list of all function files fish would use, sorted by name.
+
+
 Combining ``path``
 -------------------
 

src/builtins/path.cpp

@@ -157,6 +157,8 @@ struct options_t {  //!OCLINT(too many fields)
     bool type_valid = false;
     bool invert_valid = false;
     bool what_valid = false;
+    bool unique_valid = false;
+    bool unique = false;
     bool have_what = false;
     const wchar_t *what = nullptr;
 
@@ -348,6 +350,16 @@ static int handle_flag_v(const wchar_t **argv, parser_t &parser, io_streams_t &s
     return STATUS_INVALID_ARGS;
 }
 
+static int handle_flag_u(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
+                         const wgetopter_t &w, options_t *opts) {
+    if (opts->unique_valid) {
+        opts->unique = true;
+        return STATUS_CMD_OK;
+    }
+    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
+    return STATUS_INVALID_ARGS;
+}
+
 static int handle_flag_what(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
                          const wgetopter_t &w, options_t *opts) {
     UNUSED(argv);
@@ -373,6 +385,7 @@ static wcstring construct_short_opts(options_t *opts) {  //!OCLINT(high npath co
         short_opts.append(L"fld");
     }
     if (opts->invert_valid) short_opts.append(L"v");
+    if (opts->unique_valid) short_opts.append(L"u");
     return short_opts;
 }
 
@@ -386,6 +399,7 @@ static const struct woption long_options[] = {
                                               {L"perm", required_argument, nullptr, 'p'},
                                               {L"type", required_argument, nullptr, 't'},
                                               {L"invert", required_argument, nullptr, 't'},
+                                              {L"unique", no_argument, nullptr, 'u'},
                                               {L"what", required_argument, nullptr, 1},
                                               {}};
 
@@ -396,7 +410,8 @@ static const std::unordered_map<char, decltype(*handle_flag_q)> flag_to_function
     {'r', handle_flag_r}, {'w', handle_flag_w},
     {'x', handle_flag_x}, {'f', handle_flag_f},
     {'l', handle_flag_l}, {'d', handle_flag_d},
-    {1, handle_flag_what},
+    {'l', handle_flag_l}, {'d', handle_flag_d},
+    {'u', handle_flag_u}, {1, handle_flag_what},
 };
 
 /// Parse the arguments for flags recognized by a specific string subcommand.
@@ -700,6 +715,7 @@ static int path_sort(parser_t &parser, io_streams_t &streams, int argc, const wc
     options_t opts;
     opts.invert_valid = true;
     opts.what_valid = true;
+    opts.unique_valid = true;
     int optind;
     int retval = parse_opts(&opts, &optind, 0, argc, argv, parser, streams);
     if (retval != STATUS_CMD_OK) return retval;
@@ -745,6 +761,13 @@ static int path_sort(parser_t &parser, io_streams_t &streams, int argc, const wc
                       else
                           return (wcsfilecmp_glob(funced[a].c_str(), funced[b].c_str()) > 0);
                   });
+        if (opts.unique) {
+            list.erase(std::unique(list.begin(), list.end(),
+                              [&](const wcstring &a, const wcstring &b) {
+                                  return funced[a] == funced[b];
+                              }),
+                       list.end());
+        }
     } else {
         // Without --what, we just sort by the entire path,
         // so we have no need to transform and such.
@@ -755,6 +778,9 @@ static int path_sort(parser_t &parser, io_streams_t &streams, int argc, const wc
                       else
                           return (wcsfilecmp_glob(a.c_str(), b.c_str()) > 0);
                   });
+        if (opts.unique) {
+            list.erase(std::unique(list.begin(), list.end()), list.end());
+        }
     }
 
     for (const auto &entry : list) {

tests/checks/path.fish

@@ -155,3 +155,16 @@ path sort --what=basename {def,abc}/{456,123,789,abc,def,0} | path sort --what=d
 # CHECK: abc/789
 # CHECK: abc/abc
 # CHECK: abc/def
+
+path sort --unique --what=basename {def,abc}/{456,123,789} def/{abc,def,0} abc/{foo,bar,baz}
+# CHECK: def/0
+# CHECK: def/123
+# CHECK: def/456
+# CHECK: def/789
+# CHECK: def/abc
+# CHECK: abc/bar
+# CHECK: abc/baz
+# CHECK: def/def
+# CHECK: abc/foo
+
+