Reusing same pattern in a rule

Here is an example of grammar that I would like to have:

heredoc = "<<<" marker:[\w]+ "\n" text:[\s\S]+ "\n" marker {
    return text.join('');
}

Right now it doesn’t work but It would be nice to be able to use marker later in the rule. So I properly parse:

<<<HELLO
1
2
3
HELLO

[hildjj]

See #196 for a fully-worked example of a stack when parsing XML.

[jcubic]

@Mingun I again needed to add validation with error (now I fully understand how this works), but I think that your example is not documented. The README don’t shows that you can use {} anywhere in the code and that you can use this pattern:

name:(rule / '' { error('xxx') })

Are there any other patterns like this? If yes then they should be documented separately (maybe on Wiki list of useful single rule examples on one page), no one have time to read full grammar to search for patterns that you can use.