| import { createPath } from "./node-path"; |
| import { unionTypesMap, nodeAndUnionTypes } from "./nodes"; // recursively walks the AST starting at the given node. The callback is invoked for |
| // and object that has a 'type' property. |
| |
| function walk(context, callback) { |
| var stop = false; |
| |
| function innerWalk(context, callback) { |
| if (stop) { |
| return; |
| } |
| |
| var node = context.node; |
| |
| if (node === undefined) { |
| console.warn("traversing with an empty context"); |
| return; |
| } |
| |
| if (node._deleted === true) { |
| return; |
| } |
| |
| var path = createPath(context); |
| callback(node.type, path); |
| |
| if (path.shouldStop) { |
| stop = true; |
| return; |
| } |
| |
| Object.keys(node).forEach(function (prop) { |
| var value = node[prop]; |
| |
| if (value === null || value === undefined) { |
| return; |
| } |
| |
| var valueAsArray = Array.isArray(value) ? value : [value]; |
| valueAsArray.forEach(function (childNode) { |
| if (typeof childNode.type === "string") { |
| var childContext = { |
| node: childNode, |
| parentKey: prop, |
| parentPath: path, |
| shouldStop: false, |
| inList: Array.isArray(value) |
| }; |
| innerWalk(childContext, callback); |
| } |
| }); |
| }); |
| } |
| |
| innerWalk(context, callback); |
| } |
| |
| var noop = function noop() {}; |
| |
| export function traverse(node, visitors) { |
| var before = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : noop; |
| var after = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : noop; |
| Object.keys(visitors).forEach(function (visitor) { |
| if (!nodeAndUnionTypes.includes(visitor)) { |
| throw new Error("Unexpected visitor ".concat(visitor)); |
| } |
| }); |
| var context = { |
| node: node, |
| inList: false, |
| shouldStop: false, |
| parentPath: null, |
| parentKey: null |
| }; |
| walk(context, function (type, path) { |
| if (typeof visitors[type] === "function") { |
| before(type, path); |
| visitors[type](path); |
| after(type, path); |
| } |
| |
| var unionTypes = unionTypesMap[type]; |
| |
| if (!unionTypes) { |
| throw new Error("Unexpected node type ".concat(type)); |
| } |
| |
| unionTypes.forEach(function (unionType) { |
| if (typeof visitors[unionType] === "function") { |
| before(unionType, path); |
| visitors[unionType](path); |
| after(unionType, path); |
| } |
| }); |
| }); |
| } |