Node

The basic building block of the Abstract Syntax Tree (AST). In general a Node represents non-terminals in the language grammar; however, some terminals are kept in the tree such as identifiers and literals.

Two key things make up an AST node’s documentation. The node’s SyntaxKind which identifies its type within the AST, and its interface, the API the node provides when instantiated into the AST.

Here are a few key interface Node members:

• TextRange members that identify the node’s start and end in the source file.
• parent?: Node the parent of the node in the AST.

There are other additional members for Node flags and modifiers etc. that you can lookup by searching interface Node in the source code but the ones we mentioned are vital for node traversal.

SourceFile

• SyntaxKind.SourceFile
• interface SourceFile.

Each SourceFile is a top-level AST node that is contained in the Program.