> -----Original Message----- > From: antlr-interest-boun...@antlr.org [mailto:antlr-interest- > boun...@antlr.org] On Behalf Of Ruslan Zasukhin > Sent: Saturday, October 15, 2011 7:54 AM > To: antlr-interest@antlr.org > Subject: [antlr-interest] [Q] how rewrite tree for this simple rule > with alternatives? > > Hi All, > Hi Terrence, > > > What still wonders me a lot in ANTLR v3 is that fact that we must > quite often to use helper rules_leafs to build trees. >
> ============================================ > Because attempts to make it in SINGLE rule way -- not works: > > alter_trigger_statement > : T_ALTER T_TRIGGER trigger_name ( T_ENABLE | T_DISABLE ) > -> ^( ALTER_TRIGGER trigger_name (T_ENABLE | T_DISABLE) ) > ; > > > PROBLEM comes from this alternative (T_ENABLE | T_DISABLE ) ... > We cannot label it right? > > And it is wrong make both tokens optional > > alter_trigger_statement > : T_ALTER T_TRIGGER trigger_name ( T_ENABLE | T_DISABLE ) > -> ^( ALTER_TRIGGER trigger_name T_ENABLE? T_DISABLE? ) > ; > -> ^( ALTER_TRIGGER trigger_name T_ENABLE? T_DISABLE? ) You just have to think about the rewrite ordinality indicators, not the rule syntax. Jim List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups "il-antlr-interest" group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
