[antlr-interest] Rewriting to Flat Tree Nodes for Associative Multiary Operators

[Randall R Schulz]

Hi,

Next question.

(I've been spoiled by working mostly with strictly prefix languages in 
the past...)


How might I alter a rule such as this one:

op790Formula
    :   (op780Formula -> op780Formula)
        (
            Or rDisjunct = op790Formula
        ->  ^(Or $op790Formula $rDisjunct)
        ) ?
    ;

(parenthetically:
op780Formula
    :   ... // Next higher level of operator precedence (And)
    ;
)

which, when given input like this:

	p | q | r | s

produces this sort of tree:

	(Or p (Or q (Or r s)))

so that I instead get this:

	(Or p q r s)


Every variation I've tried either gives me the fully nested tree or 
elicits a org.antlr.runtime.tree.RewriteEmptyStreamException.


Thanks in advance (again).


Randall Schulz