Add an entry point for the completion tool

tools/completion/types.go

@@ -3,44 +3,62 @@
 package completion
 
 type Match struct {
-	Word        string
-	FullForm    string
-	Description string
+	Word        string `json:"word,omitempty"`
+	FullForm    string `json:"full_form,omitempty"`
+	Description string `json:"description,omitempty"`
 }
 
 type MatchGroup struct {
-	Title                    string
-	NoTrailingSpace, IsFiles bool
-	Matches                  []*Match
-	WordPrefix               string
+	Title           string   `json:"title,omitempty"`
+	NoTrailingSpace bool     `json:"no_trailing_space,omitempty"`
+	IsFiles         bool     `json:"is_files,omitempty"`
+	Matches         []*Match `json:"matches,omitempty"`
+	WordPrefix      string   `json:"word_prefix,omitempty"`
 }
 
 type Completions struct {
-	Groups     []*MatchGroup
-	WordPrefix string
+	Groups     []*MatchGroup `json:"groups,omitempty"`
+	WordPrefix string        `json:"word_prefix,omitempty"`
 
-	current_cmd *command
+	current_cmd *Command
 }
 
 type completion_func func(completions *Completions, partial_word string)
 
-type option struct {
-	name               string
-	aliases            []string
-	description        string
-	has_following_arg  bool
-	completion_for_arg completion_func
+type Option struct {
+	Name               string
+	Aliases            []string
+	Description        string
+	Has_following_arg  bool
+	Completion_for_arg completion_func
 }
 
-type command struct {
-	name        string
-	description string
+type Command struct {
+	Name        string
+	Description string
 
-	options []option
+	// List of options for this command
+	Options []*Option
 
-	subcommands       []command
-	subcommands_title string
+	// List of subcommands
+	Subcommands []*Command
+	// Optional title used as a header when displaying the list of matching sub-commands for a completion
+	Subcommands_title string
 
-	completion_for_arg     completion_func
-	stop_processing_at_arg int
+	Completion_for_arg     completion_func
+	Stop_processing_at_arg int
+}
+
+var Root = Command{Options: make([]*Option, 0), Subcommands: make([]*Command, 0, 32)}
+
+func GetCompletions(argv []string) *Completions {
+	ans := Completions{Groups: make([]*MatchGroup, 0, 4)}
+	if len(argv) > 0 {
+		exe := argv[0]
+		cmd := Root.find_subcommand(exe)
+		if cmd != nil {
+			cmd.parse_args(argv[1:], &ans)
+		}
+	}
+	return &ans
 }