node-estree-walker 0.5.1-1 / usr / lib / nodejs / estree-walker / index.js

'use strict';

Object.defineProperty(exports, "__esModule", {
	value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.walk = walk;
function walk(ast, _ref) {
	var enter = _ref.enter,
	    leave = _ref.leave;

	visit(ast, null, enter, leave);
}

var shouldSkip = false;
var context = { skip: function skip() {
		return shouldSkip = true;
	} };

var childKeys = exports.childKeys = {};

var toString = Object.prototype.toString;

function isArray(thing) {
	return toString.call(thing) === '[object Array]';
}

function visit(node, parent, enter, leave, prop, index) {
	if (!node) return;

	if (enter) {
		var _shouldSkip = shouldSkip;
		shouldSkip = false;
		enter.call(context, node, parent, prop, index);
		var skipped = shouldSkip;
		shouldSkip = _shouldSkip;

		if (skipped) return;
	}

	var keys = childKeys[node.type] || (childKeys[node.type] = Object.keys(node).filter(function (key) {
		return _typeof(node[key]) === 'object';
	}));

	for (var i = 0; i < keys.length; i += 1) {
		var key = keys[i];
		var value = node[key];

		if (isArray(value)) {
			for (var j = 0; j < value.length; j += 1) {
				visit(value[j], node, enter, leave, key, j);
			}
		} else if (value && value.type) {
			visit(value, node, enter, leave, key, null);
		}
	}

	if (leave) {
		leave(node, parent, prop, index);
	}
}