Блин, а я всегда думал, что за абстактное дерево
> An abstract syntax tree (AST) captures the essential structure of the input in a tree
form, while omitting unnecessary syntactic details. ASTs can be distinguished from
concrete syntax trees by their omission of tree nodes to represent punctuation marks
such as semi-colons to terminate statements or commas to separate function arguments.
ASTs also omit tree nodes that represent unary productions in the grammar. Such
information is directly represented in ASTs by the structure of the tree.
Это о том, что такое "абстрактный синтаксис" и чем он отличается от конкретного.