pretty tree output (like pest.rs sandbox)

[shanemikel]

I can't seem to find any methods or functions for the pretty tree output you have in the pest.rs sandbox tool.

The output is like so:

- RuleWithMultipleChildren
  - RuleWithOneChild > RuleWithMultipleChildren
    - RuleWithOneChild > TerminalRule: "tok1"
    - RuleWithOneChild > TerminalRule: "tok2"

I find that this has been really nice for debugging, so I implemented my own (pretty ugly) version of it here (https://gist.github.com/shanemikel/72e4a71452a7663749c6cb030136b855). From what I can tell, it produces the exact same output as the website.

I would very much appreciate if the already implemented version would be exposed in the pest library itself.

---

This brings me to a question. The following line from this function (line no. 23... can't figure out how to link a line from the gist):

let children: Vec<_> = pairs.clone().into_iter().collect();
let child_count = children.len();

Now does this simply clone the iterator, or make a deep copy of the entire parse tree?

[dragostis]

The code that formats the output is in the site repo.

While this might seem like a good idea, it will probably not be an area of focus for the next major version of pest since we're exploring ways of deprecating the Pair/Pairs API in favor of a simpler, more flexible API.

[shanemikel]

@dragostis Thank god (or just the Pest devs)! The Pairs API is awful to use.
EDIT Sorry author of Pairs...

[shanemikel]

Holy crap that implementation is soo much cleaner than mine.