1 files changed, 31 insertions, 13 deletions

diff --git a/jim-subcmd.c b/jim-subcmd.c
index c522830..1a090d5 100644
--- a/jim-subcmd.c
+++ b/jim-subcmd.c
@@ -41,18 +41,14 @@ static void add_commands(Jim_Interp *interp, const jim_subcmd_type * ct, const c
 static void bad_subcmd(Jim_Interp *interp, const jim_subcmd_type * command_table, const char *type,
     Jim_Obj *cmd, Jim_Obj *subcmd)
 {
-    Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
-    Jim_AppendStrings(interp, Jim_GetResult(interp), Jim_String(cmd), ", ", type,
-        " command \"", Jim_String(subcmd), "\": should be ", NULL);
+    Jim_SetResultFormatted(interp, "%#s, %s command \"%#s\": should be ", cmd, type, subcmd);
     add_commands(interp, command_table, ", ");
 }
 
 static void show_cmd_usage(Jim_Interp *interp, const jim_subcmd_type * command_table, int argc,
     Jim_Obj *const *argv)
 {
-    Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
-    Jim_AppendStrings(interp, Jim_GetResult(interp), "Usage: \"", Jim_String(argv[0]),
-        " command ... \", where command is one of: ", NULL);
+    Jim_SetResultFormatted(interp, "Usage: \"%#s command ... \", where command is one of: ", argv[0]);
     add_commands(interp, command_table, ", ");
 }
 
@@ -74,6 +70,18 @@ static void set_wrong_args(Jim_Interp *interp, const jim_subcmd_type * command_t
     Jim_AppendStrings(interp, Jim_GetResult(interp), "\"", NULL);
 }
 
+/* internal rep is stored in ptrIntvalue
+ *  ptr = command_table
+ *  int1 = index
+ */
+static const Jim_ObjType subcmdLookupObjType = {
+    "subcmd-lookup",
+    NULL,
+    NULL,
+    NULL,
+    JIM_TYPE_REFERENCES
+};
+
 const jim_subcmd_type *Jim_ParseSubCmd(Jim_Interp *interp, const jim_subcmd_type * command_table,
     int argc, Jim_Obj *const *argv)
 {
@@ -82,21 +90,24 @@ const jim_subcmd_type *Jim_ParseSubCmd(Jim_Interp *interp, const jim_subcmd_type
     int cmdlen;
     Jim_Obj *cmd;
     const char *cmdstr;
-    const char *cmdname;
     int help = 0;
 
-    cmdname = Jim_String(argv[0]);
-
     if (argc < 2) {
-        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
-        Jim_AppendStrings(interp, Jim_GetResult(interp), "wrong # args: should be \"", cmdname,
-            " command ...\"\n", NULL);
-        Jim_AppendStrings(interp, Jim_GetResult(interp), "Use \"", cmdname, " -help ?command?\" for help", NULL);
+        Jim_SetResultFormatted(interp, "wrong # args: should be \"%#s command ...\"\n"
+            "Use \"%#s -help ?command?\" for help", argv[0], argv[0]);
         return 0;
     }
 
     cmd = argv[1];
 
+    /* Use cached lookup if possible */
+    if (cmd->typePtr == &subcmdLookupObjType) {
+        if (cmd->internalRep.ptrIntValue.ptr == command_table) {
+            ct = command_table + cmd->internalRep.ptrIntValue.int1;
+            goto found;
+        }
+    }
+
     /* Check for the help command */
     if (Jim_CompareStringImmediate(interp, cmd, "-help")) {
         if (argc == 2) {
@@ -164,6 +175,13 @@ const jim_subcmd_type *Jim_ParseSubCmd(Jim_Interp *interp, const jim_subcmd_type
         return &dummy_subcmd;
     }
 
+    /* Cache the result for a successful non-help lookup */
+    Jim_FreeIntRep(interp, cmd);
+    cmd->typePtr = &subcmdLookupObjType;
+    cmd->internalRep.ptrIntValue.ptr = (void *)command_table;
+    cmd->internalRep.ptrIntValue.int1 = ct - command_table;
+
+found:
     /* Check the number of args */
     if (argc - 2 < ct->minargs || (ct->maxargs >= 0 && argc - 2 > ct->maxargs)) {
         Jim_SetResultString(interp, "wrong # args: should be \"", -1);