Implement 'workspace number <number>' to switch to named workspaces

docs/userguide

@@ -1351,7 +1351,10 @@ bindsym mod+2 workspace 2: www
 Note that the workspace will really be named "1: mail". i3 treats workspace
 names beginning with a number in a slightly special way. Normally, named
 workspaces are ordered the way they appeared. When they start with a number, i3
-will order them numerically.
+will order them numerically. Also, you will be able to use +workspace number 1+
+to switch to the workspace which begins with number 1, regardless of which name
+it has. This is useful in case you are changing the workspace’s name
+dynamically.
 
 [[resizingconfig]]
 

include/commands.h

@@ -91,6 +91,12 @@ void cmd_append_layout(I3_CMD, char *path);
  */
 void cmd_workspace(I3_CMD, char *which);
 
+/**
+ * Implementation of 'workspace number <number>'
+ *
+ */
+void cmd_workspace_number(I3_CMD, char *which);
+
 /**
  * Implementation of 'workspace back_and_forth'.
  *

parser-specs/commands.spec

@@ -77,14 +77,21 @@ state APPEND_LAYOUT:
 # workspace next|prev|next_on_output|prev_on_output
 # workspace back_and_forth
 # workspace <name>
+# workspace number <number>
 state WORKSPACE:
   direction = 'next_on_output', 'prev_on_output', 'next', 'prev'
       -> call cmd_workspace($direction)
   'back_and_forth'
       -> call cmd_workspace_back_and_forth()
+  'number'
+      -> WORKSPACE_NUMBER
   workspace = string 
       -> call cmd_workspace_name($workspace)
 
+state WORKSPACE_NUMBER:
+  workspace = string
+      -> call cmd_workspace_number($workspace)
+
 # focus left|right|up|down
 # focus output <output>
 # focus tiling|floating|mode_toggle

src/commands.c

@@ -676,6 +676,43 @@ void cmd_workspace(I3_CMD, char *which) {
     cmd_output->json_output = sstrdup("{\"success\": true}");
 }
 
+/*
+ * Implementation of 'workspace number <number>'
+ *
+ */
+void cmd_workspace_number(I3_CMD, char *which) {
+    Con *output, *workspace;
+
+    char *endptr = NULL;
+    long parsed_num = strtol(which, &endptr, 10);
+    if (parsed_num == LONG_MIN ||
+        parsed_num == LONG_MAX ||
+        parsed_num < 0 ||
+        *endptr != '\0') {
+        LOG("Could not parse \"%s\" as a number.\n", which);
+        cmd_output->json_output = sstrdup("{\"success\": false, "
+                "\"error\": \"Could not parse number\"}");
+        return;
+    }
+
+    TAILQ_FOREACH(output, &(croot->nodes_head), nodes)
+        GREP_FIRST(workspace, output_get_content(output),
+            child->num == parsed_num);
+
+    if (!workspace) {
+        LOG("There is no workspace with number %d.\n", parsed_num);
+        cmd_output->json_output = sstrdup("{\"success\": false, "
+                "\"error\": \"No such workspace\"}");
+        return;
+    }
+
+    workspace_show(workspace);
+
+    cmd_output->needs_tree_render = true;
+    // XXX: default reply for now, make this a better reply
+    cmd_output->json_output = sstrdup("{\"success\": true}");
+}
+
 /*
  * Implementation of 'workspace back_and_forth'.
  *

testcases/t/117-workspace.t

@@ -117,4 +117,21 @@ $ws = get_ws("aa: $tmp");
 ok(defined($ws), "workspace aa: $tmp was created");
 is($ws->{num}, -1, 'workspace number is -1');
 
+################################################################################
+# Check that we can go to workspace "4: foo" with the command
+# "workspace number 4".
+################################################################################
+
+ok(!workspace_exists('4'), 'workspace 4 does not exist');
+ok(!workspace_exists('4: foo'), 'workspace 4: foo does not exist yet');
+cmd 'workspace 4: foo';
+ok(workspace_exists('4: foo'), 'workspace 4: foo was created');
+cmd 'open';
+
+cmd 'workspace 3';
+ok(workspace_exists('4: foo'), 'workspace 4: foo still open');
+cmd 'workspace number 4';
+is(focused_ws(), '4: foo', 'now on workspace 4: foo');
+ok(!workspace_exists('4'), 'workspace 4 still does not exist');
+
 done_testing;