[antlr-interest] ANTLR trees and adaptors

[Manu]

Sorry, the examples weren't in ANTLR notation. In ANTLR notation it
will be something like:

1) ^(nil a b c)
2) ^(d e f g)

2006/12/25, Manu <manunews at gmail.com>:
> The tree construction seems a bit counterintuitive to me, having the
> code split in the tree and in the adaptor, with operations that have
> different behaviour if the tree has nil nodes or not.
>
> Wouldn't it be easier to implement a more robust tree data structure
> that can handle all the scenarios orthogonally?
>
> For example, defining a Tree class and TreeNode class. A tree has
> always an empty tree node where it can't store information as its root
> but it is used just as a place holder. The real data are the childs of
> that place holder. A tree node has a list of childs and maybe a
> reference to its parent. With this model a tree can have more than 1
> root tree node below the place holder tree node. This is not a
> problem, is an added feature.
>
> Some examples:
>
> 1) (a b c) will be represented as:
>
> PLACEHOLDER
> |   |   |
> a  b  c
>
> 2) (d (e f g)) will be represented as:
>
> PLACEHOLDER
> |
> d
> |
> --------
> |   |   |
> e  f  g
>
> What do you think? Am I the only one that thinks this is better?
>