tree-transformer v1.0.0

Tree Transformer

Translate nodes in the tree.

Like Tree Visitor, but actions can return a value to replace the node being processed.

API

var Transformer = require('tree-transformer');

var nodes = [
	{ type: 'number', value: 1 },
	{ type: 'string', value: 'abc', quote: '"' }
];
var transformer = new Transformer({
	node: function (node) {
	    return node.value;
	}
});
transformer.visit(nodes); // nodes now equals to [1, 'abc']

Replacing only happens when visit an array of nodes.

Some returned values have special meanings:

• null - remove the node
• undefined - do nothing to the node

• an array of nodes - replace the node with the array of nodes, but the result array is flattened.

  	var Transformer = require('tree-transformer');
  
  	var nodes = [
  		{ type: 'number', value: 1 }
  		{ type: 'number', value: 3 }
  	];
  	var transformer = new Transformer({
  		number: function (number) {
  		    return [number.value, number.value + 1];
  		}
  	});
  	transformer.visit(nodes); // nodes now equals to [1, 2, 3, 4]

• others - replace the node with the value

When visiting a single node, visit(node) returns the returned value of the corresponding action, unless the action returns undefined, in which case the original node is returned.

When visiting an array of nodes, the result array is returned.