1
|
import { createPath } from "./node-path";
|
2
|
import { unionTypesMap, nodeAndUnionTypes } from "./nodes"; // recursively walks the AST starting at the given node. The callback is invoked for
|
3
|
// and object that has a 'type' property.
|
4
|
|
5
|
function walk(context, callback) {
|
6
|
var stop = false;
|
7
|
|
8
|
function innerWalk(context, callback) {
|
9
|
if (stop) {
|
10
|
return;
|
11
|
}
|
12
|
|
13
|
var node = context.node;
|
14
|
|
15
|
if (node === undefined) {
|
16
|
console.warn("traversing with an empty context");
|
17
|
return;
|
18
|
}
|
19
|
|
20
|
if (node._deleted === true) {
|
21
|
return;
|
22
|
}
|
23
|
|
24
|
var path = createPath(context);
|
25
|
callback(node.type, path);
|
26
|
|
27
|
if (path.shouldStop) {
|
28
|
stop = true;
|
29
|
return;
|
30
|
}
|
31
|
|
32
|
Object.keys(node).forEach(function (prop) {
|
33
|
var value = node[prop];
|
34
|
|
35
|
if (value === null || value === undefined) {
|
36
|
return;
|
37
|
}
|
38
|
|
39
|
var valueAsArray = Array.isArray(value) ? value : [value];
|
40
|
valueAsArray.forEach(function (childNode) {
|
41
|
if (typeof childNode.type === "string") {
|
42
|
var childContext = {
|
43
|
node: childNode,
|
44
|
parentKey: prop,
|
45
|
parentPath: path,
|
46
|
shouldStop: false,
|
47
|
inList: Array.isArray(value)
|
48
|
};
|
49
|
innerWalk(childContext, callback);
|
50
|
}
|
51
|
});
|
52
|
});
|
53
|
}
|
54
|
|
55
|
innerWalk(context, callback);
|
56
|
}
|
57
|
|
58
|
var noop = function noop() {};
|
59
|
|
60
|
export function traverse(node, visitors) {
|
61
|
var before = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : noop;
|
62
|
var after = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : noop;
|
63
|
Object.keys(visitors).forEach(function (visitor) {
|
64
|
if (!nodeAndUnionTypes.includes(visitor)) {
|
65
|
throw new Error("Unexpected visitor ".concat(visitor));
|
66
|
}
|
67
|
});
|
68
|
var context = {
|
69
|
node: node,
|
70
|
inList: false,
|
71
|
shouldStop: false,
|
72
|
parentPath: null,
|
73
|
parentKey: null
|
74
|
};
|
75
|
walk(context, function (type, path) {
|
76
|
if (typeof visitors[type] === "function") {
|
77
|
before(type, path);
|
78
|
visitors[type](path);
|
79
|
after(type, path);
|
80
|
}
|
81
|
|
82
|
var unionTypes = unionTypesMap[type];
|
83
|
|
84
|
if (!unionTypes) {
|
85
|
throw new Error("Unexpected node type ".concat(type));
|
86
|
}
|
87
|
|
88
|
unionTypes.forEach(function (unionType) {
|
89
|
if (typeof visitors[unionType] === "function") {
|
90
|
before(unionType, path);
|
91
|
visitors[unionType](path);
|
92
|
after(unionType, path);
|
93
|
}
|
94
|
});
|
95
|
});
|
96
|
}
|