TypeScript Transformations API

typescript.d.ts

/**
 * Visits a Node using the supplied visitor, possibly returning a new Node in its place.
 */
function visitNode<T extends Node>(node: T, visitor: Visitor): T;

/**
 * Visits a NodeArray using the supplied visitor, possibly returning a new NodeArray in
 * its place.
 */
function visitNodes<T extends Node>(nodes: NodeArray<T>, visitor: Visitor): NodeArray<T>;

/**
 * Visits each child of a Node using the supplied visitor, possibly returning a new Node
 * of the same kind in its place.
 */
function visitEachChild<T extends Node>(node: T, visitor: Visitor,
  context: TransformationContext): T;

/**
 * A function that accepts and possibly transforms a node.
 */
type Visitor =
  (node: Node) => Node | Node[];

/**
 * A function that transforms a node.
 */
type Transformer<T extends Node> =
  (node: T) => T;

/**
 * A function that is used to initialize and return a `Transformer` callback, which
 * in turn will be used to transform one or more nodes.
 */
type TransformerFactory<T extends Node> =
  (context: TransformationContext) => Transformer<T>;