notes: new architecture for cmdgroup

NOTES.md

@@ -208,26 +208,93 @@ not remain in effect after the subshell completes.
 The exit status of this construct is the exit status of LIST.
 
 ```c
-struct s_cmdgroup;
+typedef enum e_cmdgroup_item_type
+{
+   TYPE_INVALID,
+   TYPE_CMDGROUP,
+   TYPE_PIPELINE,
+}  t_cmdgroup_item_type;
 
-typedef struct s_cmdgroup_item
+typedef struct s_cmdlist_item
 {
 	enum e_cmdgroup_item_type	type;
 	union u_cmdgroup_item_inner
 	{
 		t_cmdgroup			*cmdgroup;
-		struct s_cmdlist	*cmdlist;
+      struct s_pipeline *pipeline;
 	}	inner;
 }	t_cmdgroup_item;
 
+typedef s_cmdlist
+{
+   struct s_cmdlist_item   *cmds;
+   int                     num_cmds;
+   struct s_operators      *operators;
+}  t_cmdlist;
+
 typedef struct s_cmdgroup
 {
-	int 					item_num;
-	struct s_cmdgroup_item 	*items;
-	struct s_redirects		*redirections;
+	struct s_cmdlist           item;
+	struct s_redirection_list	*redirections;
 }	t_cmdgroup;
 ```
 
+```c
+// (cmd1) && (cmd2)
+
+t_cmdgroup
+{
+   item = t_cmdlist
+   {
+      cmds = [
+         t_cmdlist_item
+         {
+            type = TYPE_CMDGROUP
+            inner = t_cmdgroup
+            {
+               item = t_cmdlist
+               {
+                  cmds = [
+                     t_cmdlist_item
+                     {
+                        type = TYPE_PIPELINE
+                        inner = t_pipeline "cmd1"
+                     }
+                  ]
+                  num_cmds = 1
+                  operators = [OP_END]
+               }
+               redirections = NULL
+            }
+         }
+         t_cmdlist_item
+         {
+            type = TYPE_CMDGROUP
+            inner = t_cmdgroup
+            {
+               item = t_cmdlist
+               {
+                  cmds = [
+                     t_cmdlist_item
+                     {
+                        type = TYPE_PIPELINE
+                        inner = t_pipeline "cmd2"
+                     }
+                  ]
+                  num_cmds = 1
+                  operators = [OP_END]
+               }
+               redirections = NULL
+            }
+         }
+      ]
+      num_cmd = 2
+      operators = [OP_AND, OP_END]
+   }
+   redirections = NULL
+}
+```
+
 ### Shell Expansion
 
 cf. 3.5 Shell Expansions