Suggestions for sub command names as well

tools/cli/command.go

@@ -301,6 +301,31 @@ func (self *Command) GetVisibleOptions() ([]string, map[string][]*Option) {
 	return group_titles, gmap
 }
 
+func sort_levenshtein_matches(q string, matches []string) {
+	utils.StableSort(matches, func(a, b string) bool {
+		la, lb := utils.LevenshteinDistance(a, q, true), utils.LevenshteinDistance(b, q, true)
+		if la != lb {
+			return la < lb
+		}
+		return a < b
+	})
+
+}
+
+func (self *Command) SuggestionsForCommand(name string, max_distance int /* good default is 2 */) []string {
+	ans := make([]string, 0, 8)
+	q := strings.ToLower(name)
+	for _, g := range self.SubCommandGroups {
+		for _, sc := range g.SubCommands {
+			if utils.LevenshteinDistance(sc.Name, q, true) <= max_distance {
+				ans = append(ans, sc.Name)
+			}
+		}
+	}
+	sort_levenshtein_matches(q, ans)
+	return ans
+}
+
 func (self *Command) SuggestionsForOption(name_with_hyphens string, max_distance int /* good default is 2 */) []string {
 	ans := make([]string, 0, 8)
 	q := strings.ToLower(name_with_hyphens)
@@ -313,13 +338,7 @@ func (self *Command) SuggestionsForOption(name_with_hyphens string, max_distance
 		}
 		return nil
 	})
-	utils.StableSort(ans, func(a, b string) bool {
+	sort_levenshtein_matches(q, ans)
-		la, lb := utils.LevenshteinDistance(a, q, true), utils.LevenshteinDistance(b, q, true)
-		if la != lb {
-			return la < lb
-		}
-		return a < b
-	})
 	return ans
 }
 

tools/cli/parse-args.go

@@ -101,6 +101,10 @@ func (self *Command) parse_args(ctx *Context, args []string) error {
 					}
 					if !self.SubCommandIsOptional {
 						if len(possible_cmds) == 0 {
+							possibles := self.SuggestionsForCommand(arg, 2)
+							if len(possibles) > 0 {
+								return &ParseError{Message: fmt.Sprintf("Unknown subcommand: :yellow:`%s`. Did you mean:\n\t%s", arg, strings.Join(possibles, "\n\t"))}
+							}
 							return &ParseError{Message: fmt.Sprintf(":yellow:`%s` is not a known subcommand for :emph:`%s`. Use --help to get a list of valid subcommands.", arg, self.Name)}
 						}
 						cn := make([]string, len(possible_cmds))