4 files changed, 55 insertions, 10 deletions
diff --git a/model/assignment.go b/model/assignment.go
new file mode 100644
index 0000000..746e2b3
--- /dev/null
+++ b/model/assignment.go
@@ -0,0 +1,6 @@
+package model
+
+type Assignment struct {
+	Key   string
+	Value Values
+}
diff --git a/model/command.go b/model/command.go
new file mode 100644
index 0000000..237e94f
--- /dev/null
+++ b/model/command.go
@@ -0,0 +1,9 @@
+package model
+
+type Command struct {
+	Name      string
+	Arguments Values
+	Body      *Doc
+}
+
+type Commands []*Command
diff --git a/model/doc.go b/model/doc.go
index 76f03e4..9c13a4c 100644
--- a/model/doc.go
+++ b/model/doc.go
@@ -1,18 +1,41 @@
 package model
 
-type Doc []any
+type Doc struct {
+	items    []any
+	vars     map[string]Values
+	commands map[string]Commands
+}
 
-type Assignment struct {
-	Key   string
-	Value []Value
+func New(cap int) *Doc {
+	return &Doc{
+		items:    make([]any, 0, cap),
+		vars:     make(map[string]Values, cap),
+		commands: make(map[string]Commands, cap),
+	}
 }
 
-type Command struct {
-	Name      string
-	Arguments []Value
-	Body      Doc
+func (d *Doc) AppendAssignment(e *Assignment) {
+	d.items = append(d.items, e)
+	d.vars[e.Key] = append(d.vars[e.Key], e.Value...)
 }
 
-type Value any
+func (d *Doc) AppendCommand(c *Command) {
+	d.items = append(d.items, c)
+	d.commands[c.Name] = append(d.commands[c.Name], c)
+}
 
-type Word string
+func (d *Doc) Vars() map[string]Values {
+	return d.vars
+}
+
+func (d *Doc) Get(key string) Values {
+	return d.vars[key]
+}
+
+func (d *Doc) Commands(name string) Commands {
+	return d.commands[name]
+}
+
+func (d *Doc) Items() []any {
+	return d.items
+}
diff --git a/model/value.go b/model/value.go
new file mode 100644
index 0000000..8c995fe
--- /dev/null
+++ b/model/value.go
@@ -0,0 +1,7 @@
+package model
+
+type Value any
+
+type Values []Value
+
+type Word string