Merge branch 'feat-walk-override-container-elms' into 'master'

feat(walk): Allow overriding container elms

See merge request luk3yx/minetest-formspec_ast!1

README.md

@@ -10,9 +10,10 @@ A Minetest mod library to make modifying formspecs easier.
     and returns a formspec string.
  - `formspec_ast.interpret(string_or_tree)`: Returns a formspec string after
     (optionally parsing) and unparsing the formspec provided.
- - `formspec_ast.walk(tree)`: Returns an iterator (use this directly in a for
+ - `formspec_ast.walk(tree, optional_container_set)`: Returns an iterator (use this directly in a for
     loop) that will return all nodes in a tree, including ones inside
-    containers.
+    containers. The containers are recognised by `type`, and can be overriden
+    with a table of `name` to `true` relationships in `optional_container_set`
  - `formspec_ast.find(tree, node_type)`: Similar to `walk(tree)`, however only
     returns `node_type` nodes.
  - `formspec_ast.get_element_by_name(tree, name)`: Returns the first element in

helpers.lua

@@ -71,9 +71,9 @@ end
 
 -- Returns an iterator over all nodes in a formspec AST, including ones in
 -- containers.
-local container_elems = {container = true, scroll_container = true}
-function formspec_ast.walk(tree)
-    return walk_inner(tree, container_elems)
+local default_container_elems = {container = true, scroll_container = true}
+function formspec_ast.walk(tree, provided_container_elms)
+    return walk_inner(tree, provided_container_elms or default_container_elems)
 end
 
 -- Similar to formspec_ast.walk(), however only returns nodes which have a type