pchiusano

-- A port of: http://semantic-domain.blogspot.com/2015/03/abstract-binding-trees.html

{-# LANGUAGE DeriveFunctor #-}

module ABT where

import qualified Data.Foldable as Foldable
import Data.Foldable (Foldable)
import Data.Set (Set)
import qualified Data.Set as Set

mlent

    var parsetree = function(selector, options) {
        this.el = document.querySelector(selector);
        this.options = options || {};
 
        if (this.el == null)
            console.log("Could not find DOM object");
 
        return this;
    };
 

puffnfresh

How do we add extra information to a tree? This has been called [The
AST Typing
Problem](http://blog.ezyang.com/2013/05/the-ast-typing-problem/).

After being hit with this problem in Roy's new type-inference engine,
I tried figuring out how to represent the algorithm. I eventually
realised that it looked like a comonadic operation. Turns out it's
been done before but I couldn't find any complete example.

Below is some literate Haskell to show how to use the Cofree Comonad