This page is a glimpse at StarTransformer, the language-independent follow-up of JTransformer. It documents already available predicates that can be used to query ASTs of any language for which a Meta-Model has been specified.

→ Notation used in the following

• ast_languages

The predicates used to specify the Meta-Model of any language should not be queried directly, since they represent the most low-level details. Much more convenient predicates for querying the metamodel, and analysing, accessing, or navigating an AST in a language-independent manner are documented in the sections below.

Meta-level information about the structure of a language's AST (AST nodes and relations between them):

• ast_node_type_for_id ← Renamed in JT 2.8.2. Previously called “ast_node_type_value”
• ast_node_template_for_id
• ast_node_term→ rename to “ast_node_template”
• ast_node_signature
• ast_relation_term → rename to “ast_relation_template”
• ast_relation_signature

Getting the complete AST node for an id or just its attribute values:

• ast_node_for_id
• ast_node_attributes

Navigation through an AST along arbitrary edges (that is, arguments referring to other nodes):

• ast_edge_value

Particular support for navigating upwards (to immediate parents and transitive ancestors):

• ast_parent
• ast_parent_value_or_null
• ast_ancestor

Particular support for navigating downwards (to explicit and implicit subtrees):

• ast_node_sub_trees
• ast_unreferenced_sub_trees