How do we access the nlcst from remark-retext mutate mode?

[tvquizphd]

Initial question

var unified = require('unified')
var parse = require('remark-parse')
var english = require('retext-english')
var remark2retext = require('remark-retext')

var tree_from_md = unified().use(parse).use(remark2retext, english.Parser).parse('## Hello World')
var tree_from_text = unified().use(english).parse('Hello World')

I would expect both tree_from_md and tree_from_text to be identical nlcst objects, based on the unified docs explanation of mutate mode:

it sets a new syntax tree and discards the origin tree.

However, tree_from_md.children[0].type == 'heading' while tree_from_text.children[0].type == 'ParagraphNode'. This example (among others) indicates to me that the tree produced using remark2retext remains an unmodified mdast instead of my desired output of a modified nlcst.

As I'm very new to unified, and unist in general, I'm sure what I'm observing is the expected behavior while I'm simply misunderstanding the documentation. So, essentially, what I'm looking for is how to retrieve an nlcst the output of remark-retext.

Temporary solutions

This solution requires me to include the following imports:

var toNlcst = require('mdast-util-to-nlcst')
var vfile = require('vfile')

I can run mdast-util-to-nlcst directly in one of two ways: either (redundantly?) on the output of remark-retext in Option 1, or by bypassing remark-retext entirely in Option 2.

// Option 1
var tree_from_md = unified().use(parse).use(remark2retext, english.Parser).parse('## Hello World')
var nlcst_from_md = toNlcst(tree_from_md, vfile('## Hello World'), english.Parser)

// Option 2
var tree_from_direct_md = unified().use(parse).parse('## Hello World')
var nlcst_from_direct_md = toNlcst(tree_from_direct_md, vfile('## Hello World'), english.Parser)

In either case, the first child of the tree is of type ParagraphNode, which indicates to me that this tree is in fact nlcst. However, the mdast-util-to-nlcst documentation suggests that I instead use remark-retext. Is there in fact a way to retrieve nlcst trees from remark-retext without directly calling mdast-util-to-nlcst?

Happy holidays and many thanks to anyone who might happen to see this.

[wooorm]

Hi there!

The .parse function only performs the parsing stage. .run and .runSync can be used to perform the run stage (running plugins).
More info available here.

And it’s good to see them as different processors:

var processor = unified().use(parse).use(remark2retext, english.Parser)

var tree_from_md = processor.runSync(processor.parse(doc))

[tvquizphd]

Thanks for such a quick response! This makes a lot of sense: I should have read the docs more carefully to understand the parse, run, and stringify methods of a processor. I think it's pretty clear now. Thanks again.