This repository has been archived by the owner on Apr 19, 2019. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 7
/
traverser.js
110 lines (97 loc) · 3.29 KB
/
traverser.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
"use strict";
var assert = require("assert");
var estraverse = require("estraverse");
var estest = require("./estest");
var utils = require("./utils");
// Depth-first
exports.traverse = function (node, stack, processor) {
assert.ok(estest.isNode(node));
assert.ok(Array.isArray(stack));
assert.equal(typeof processor, "function");
exports.visitChildren(node, (child, key) => {
return exports.traverse(child, [ { node: node, key: key } ].concat(stack), processor);
});
return processor(node, [ { node: node } ].concat(stack));
};
// Breadth-first
exports.traverseEx = function (node, stack, processor) {
assert.ok(estest.isNode(node));
assert.ok(Array.isArray(stack));
assert.equal(typeof processor, "function");
var abort = false;
var controller = {
abort: function() {
abort = true;
}
};
var queue = [];
exports.visitChildrenEx(node, (child, key) => {
var repl = processor.call(controller, child, [ { node: node } ].concat(stack));
if (repl == child) {
queue.push({
child: child,
key: key
});
}
return repl;
});
if (!abort) {
queue.every(elem => {
exports.traverseEx.call(controller, elem.child, [ { node: node, key: elem.key } ].concat(stack), processor);
return !abort;
});
}
return node;
};
exports.visitChildren = function (node, processor) {
assert.ok(estest.isNode(node));
assert.equal(typeof processor, "function");
var keys = estraverse.VisitorKeys[node.type] || [];
keys.forEach(key => {
if (Array.isArray(node[key])) {
node[key] = node[key].map(x => {
var repl = processor(x, key);
assert(repl);
return repl;
});
} else if (node[key]) {
var repl = processor(node[key], key);
assert(repl);
node[key] = repl;
}
});
};
exports.visitChildrenEx = function (node, processor) {
assert.ok(estest.isNode(node));
assert.equal(typeof processor, "function");
var keys = estraverse.VisitorKeys[node.type] || [];
keys.forEach(key => {
if (Array.isArray(node[key])) {
let i = node[key].length;
while (i--) {
assert(node[key][i]);
let replacement = processor(node[key][i], key);
assert(replacement);
if (replacement.length == 1) {
replacement = replacement[0];
}
if (Array.isArray(replacement)) {
utils.splice(node[key], i, 1, replacement);
} else {
node[key][i] = replacement;
}
}
} else if (node[key]) {
let replacement = processor(node[key], key);
assert(replacement);
if (replacement.length == 1) {
replacement = replacement[0];
}
if (Array.isArray(replacement)) {
throw new Error("Cannot use array here: " + node.type + "." + key + "\n" + JSON.stringify(node) + "\n" + JSON.stringify(replacement));
} else {
node[key] = replacement;
}
}
});
};