Implement cat command

.godo/godo.json

@@ -1,3 +1,8 @@
-{"UI tags":{"id":"UI tags","description":"filter the items by tags in the UI, listing the tags for selection","duration":0,"done":false,"tags":{}},"list tags":{"id":"list tags","description":"command like 'godo list tag1 tag2 tag3' that lists items in tags","duration":1800000000000,"done":true,"tags":{}},"ordering":{"id":"ordering","description":"sort by custom order","duration":0,"done":false,"tags":{}},"tags":{"id":"tags","description":"command like 'godo tags' that lists the existing tags","duration":0,"done":false,"tags":{}},"untag":{"id":"untag","description":"command like tag but deletes the tag from items","duration":5400000000000,"done":true,"tags":{}}}
-":{}}}
-ription":"command like tag but deletes the tag from items","duration":5400000000000,"done":true,"tags":{}}}
+{"UI tags":{"id":"UI tags","description":"filter the items by tags in the UI, listing the tags for selection","duration":0,"done":false,"tags":{}},"list tags":{"id":"list tags","description":"command like 'godo list tag1 tag2 tag3' that lists items in tags","duration":1800000000000,"done":true,"tags":{}},"ordering":{"id":"ordering","description":"sort by custom order","duration":0,"done":false,"tags":{}},"tags":{"id":"tags","description":"command like 'godo tags' that lists the existing tags","duration":0,"done":true,"tags":{}},"untag":{"id":"untag","description":"command like tag but deletes the tag from items","duration":5400000000000,"done":true,"tags":{}}}
+
+K":{}}}}
+K":{}}}}
+RK":{}}}}
+RK":{}}}}
+RK":{}}}}
+e tag from items","duration":5400000000000,"done":true,"tags":{}}}

commands/cat.go

@@ -0,0 +1,41 @@
+package commands
+
+import (
+	"fmt"
+
+	"github.com/gabrielseibel1/godo/data"
+	"github.com/gabrielseibel1/godo/types"
+	"golang.org/x/exp/maps"
+)
+
+const CatCommandName CommandName = "cat"
+
+type Cat struct {
+	repo data.Repository
+}
+
+func (c *Cat) Parameterize(args []string) error {
+	if len(args) != 0 {
+		return errArgsCount(0, len(args))
+	}
+	return nil
+}
+
+func (c *Cat) Execute() error {
+	as, err := c.repo.List()
+	if err != nil {
+		return err
+	}
+	tags := make(map[types.ID]struct{})
+	for _, a := range as {
+		maps.Copy(tags, a.Tags())
+	}
+	for tag := range tags {
+		fmt.Println(tag)
+	}
+	return nil
+}
+
+func (c *Cat) String() string {
+	return fmt.Sprintf("command %s", CatCommandName)
+}

commands/parser.go

@@ -31,6 +31,8 @@ func NewParser(deps Deps) Parser {
 			cmd = &List{repo: deps.Repo, display: deps.Displayer}
 		case string(SublistCommandName):
 			cmd = &Sublist{repo: deps.Repo, display: deps.Displayer}
+		case string(CatCommandName):
+			cmd = &Cat{repo: deps.Repo}
 		case string(GetCommandName):
 			cmd = &Get{repo: deps.Repo, display: deps.Displayer}
 		case string(CreateCommandName):