Moved register state to scopes

src/build/ast/Count.go

@@ -0,0 +1,36 @@
+package ast
+
+import "git.akyoto.dev/cli/q/src/build/token"
+
+// Count counts how often the given token appears in the AST.
+func Count(body AST, kind token.Kind, name string) int {
+	count := 0
+
+	for _, node := range body {
+		switch node := node.(type) {
+		case *Assign:
+			count += node.Value.Count(kind, name)
+
+		case *Call:
+			count += node.Expression.Count(kind, name)
+
+		case *Define:
+			count += node.Value.Count(kind, name)
+
+		case *Return:
+			count += node.Value.Count(kind, name)
+
+		case *If:
+			count += node.Condition.Count(kind, name)
+			count += Count(node.Body, kind, name)
+
+		case *Loop:
+			count += Count(node.Body, kind, name)
+
+		default:
+			panic("unknown AST type")
+		}
+	}
+
+	return count
+}