[antlr-interest] parse tree construction after left recursion removal

[Gavin Lambert]

At 01:10 8/07/2009, Safiye Celik wrote:
>I have a rule and its tree construction such below:
>a : b | c! a c! | a d^ a
[...]
>What should I do to remove left recursion, but also provide the 
>tree I need?

Try this:

a : (b | c! a c!) (d^ a)? ;

Or this:

e : b | c! a c! ;
a : e (d^ e)* ;

(The recursion in the c alt is ok at parse time.  But it might 
make things difficult for you in the tree parser.  Could be 
helpful to insert an imaginary root at that point.)