@textlint/ast-traverse
@textlint/ast-traverse provide traversal functions for TxtAST.
This traverse function is a fork of estraverse for @textlint/markdown-to-ast.
This library is a part of textlint/textlint.
Installation
npm install @textlint/ast-traverse
Usage
var parse = require("@textlint/markdown-to-ast").parse,
Syntax = require("@textlint/markdown-to-ast").Syntax;
var traverse = require("@textlint/ast-traverse").traverse,
VisitorOption = require("@textlint/ast-traverse").VisitorOption;
var AST = parse("# Header\nHello*world*");
traverse(AST, {
enter(node) {
console.log("enter", node.type);
if (node.type === Syntax.Strong) {
return VisitorOption.Skip;
}
},
leave(node) {
console.log("leave", node.type);
}
});
Traversal rule is the same with Estraverse.
Example
Markdown:
Hello *world*
AST:
{
"start_line": 1,
"start_column": 1,
"end_line": 0,
"children": [
{
"start_line": 1,
"start_column": 1,
"end_line": 0,
"inline_content": [
{
"c": "Hello",
"raw": "Hello",
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 5
}
},
"range": [
0,
5
],
"type": "Str"
},
{
"c": " ",
"raw": " ",
"loc": {
"start": {
"line": 1,
"column": 5
},
"end": {
"line": 1,
"column": 6
}
},
"range": [
5,
6
],
"type": "Str"
},
{
"c": [
{
"c": "world",
"raw": "world",
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 5
}
},
"range": [
0,
5
],
"type": "Str"
}
],
"raw": "*world*",
"loc": {
"start": {
"line": 1,
"column": 6
},
"end": {
"line": 1,
"column": 13
}
},
"range": [
6,
13
],
"type": "Emphasis"
}
],
"children": [],
"raw": "Hello *world*",
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 13
}
},
"range": [
0,
13
],
"type": "Paragraph"
}
],
"raw": "Hello *world*",
"loc": {
"start": {
"line": 1,
"column": 0
},
"end": {
"line": 1,
"column": 13
}
},
"range": [
0,
13
],
"type": "Document"
}
Traversal all from Root(Document node):
[enter, Syntax.Document],
// # Header
[enter, Syntax.Header],
[enter, Syntax.Str],
[leave, Syntax.Str],
[leave, Syntax.Header],
// => Paragraph
[enter, Syntax.Paragraph],
[enter, Syntax.Str],
[leave, Syntax.Str],
// *world*
[enter, Syntax.Emphasis],
[enter, Syntax.Str],
[leave, Syntax.Str],
[leave, Syntax.Emphasis],
// <= Paragraph
[leave, Syntax.Paragraph],
// End
[leave, Syntax.Document]
NOTE
You want to set property on Node.
Bad example:
var TraverseController = require("@textlint/ast-traverse").Controller;
var controller = new TraverseController();
controller.traverse(ast, {
enter: function (node, parent) {
node.parent = parent;
something(node);
}
});
node.parent = parent;
cause a circular reference!
Correct example:
var TraverseController = require("@textlint/ast-traverse").Controller;
var controller = new TraverseController();
controller.traverse(ast, {
enter: function (node, parent) {
Object.defineProperty(node, "parent", {
value: parent
});
something(node);
}
});
Contributing
- Fork it!
- Create your feature branch:
git checkout -b my-new-feature
- Commit your changes:
git commit -am 'Add some feature'
- Push to the branch:
git push origin my-new-feature
- Submit a pull request :D
License
MIT
and
Includes Estraverse
Copyright (C) 2012-2013 Yusuke Suzuki
https://github.com/estools/estraverse/blob/master/LICENSE.BSD