Hi. [I'm moving this to the interest list as it is about using not building
antlr]
Do you have backtrack=true anywhere? do you have "=>" operators anywhere? I
believe that is the only way it will wrap those actions.
Ter
On Feb 28, 2011, at 12:18 PM, Susanna Siebert wrote:
> Hi everybody,
>
> we are trying to add custom bracematching to our language, Hop. For example,
> our functions are designed in the form action myAction .. end, where we are
> trying to match the "action" with the "end". To do that we added some
> semantic actions to the appropriate rules in the *.g file, that add some
> information about the position of the tokens to a hash table in a matcher
> module. This works fine except for the if-else-statements. These look like so:
>
> if_statement
> :
> firstif = IF root_expression THEN { symbol.add(new BlockDescriptor()); }
> block { symbol.popScope(); } firstend = END
> {
> MatchKeyword keyword1 = new MatchKeyword();
> keyword1.setMatchID(((CommonToken)$firstif).getStartIndex());
> keyword1.setStartOffset(((CommonToken)$firstif).getStartIndex() -
> $firstif.getLine() + 1);
> keyword1.setEndOffset(((CommonToken)$firstif).getStopIndex() -
> $firstif.getLine() + 2);
> keyword1.setIsPrefix(true);
> MatchKeyword keyword2 = new MatchKeyword();
> keyword2.setMatchID(((CommonToken)$firstif).getStartIndex());
> keyword2.setStartOffset(((CommonToken)$firstend).getStartIndex() -
> $firstend.getLine() + 1);
> keyword2.setEndOffset(((CommonToken)$firstend).getStopIndex() -
> $firstend.getLine() + 2);
> keyword2.setIsPrefix(false);
> matcher.addMatch(keyword1, keyword2);
> }
> ((firstelse = ELSE IF root_expression THEN { symbol.add(new
> BlockDescriptor()); } block { symbol.popScope(); } secondend = END
> {
> MatchKeyword keyword1 = new MatchKeyword();
> keyword1.setMatchID(((CommonToken)$firstelse).getStartIndex());
> keyword1.setStartOffset(((CommonToken)$firstelse).getStartIndex() -
> $firstelse.getLine() + 1);
> keyword1.setEndOffset(((CommonToken)$firstelse).getStopIndex() -
> $firstelse.getLine() + 2);
> keyword1.setIsPrefix(true);
> MatchKeyword keyword2 = new MatchKeyword();
> keyword2.setMatchID(((CommonToken)$firstelse).getStartIndex());
> keyword2.setStartOffset(((CommonToken)$secondend).getStartIndex() -
> $secondend.getLine() + 1);
> keyword2.setEndOffset(((CommonToken)$secondend).getStopIndex() -
> $secondend.getLine() + 2);
> keyword2.setIsPrefix(false);
> matcher.addMatch(keyword1, keyword2);
> }
> ) => (ELSE IF root_expression THEN block END))* //else if blocks
> ((secondelse = ELSE THEN { symbol.add(new BlockDescriptor()); } block {
> symbol.popScope(); } thirdend = END
> {
> MatchKeyword keyword1 = new MatchKeyword();
> keyword1.setMatchID(((CommonToken)$secondelse).getStartIndex());
> keyword1.setStartOffset(((CommonToken)$secondelse).getStartIndex() -
> $secondelse.getLine() + 1);
> keyword1.setEndOffset(((CommonToken)$secondelse).getStopIndex() -
> $secondelse.getLine() + 2);
> keyword1.setIsPrefix(true);
> MatchKeyword keyword2 = new MatchKeyword();
> keyword2.setMatchID(((CommonToken)$secondelse).getStartIndex());
> keyword2.setStartOffset(((CommonToken)$thirdend).getStartIndex() -
> $thirdend.getLine() + 1);
> keyword2.setEndOffset(((CommonToken)$thirdend).getStopIndex() -
> $thirdend.getLine() + 2);
> keyword2.setIsPrefix(false);
> matcher.addMatch(keyword1, keyword2);
> }
> ) => (ELSE THEN block END) )?
> ;
>
> The problem is that when the code is generated, the semantic actions are
> being surrounded by an if-statement that checks state.backtracking (if
> (state.backtracking == 0) {}). For the if-then part of the rule, this check
> evaluates to true but for the else-if-then and else-then it evaluates to
> false because state.backtracking is 1. However, backtracking is turned off.
>
> My questions now are:
> Why is a check for state.backtracking added when code is generated even if
> backtracking is turned off?
> How can I make sure that the semantic actions of the else-if-then and
> else-then are being executed?
>
> I appreciate your help.
>
> Best regards,
>
> Susanna Siebert
> _______________________________________________
> antlr-dev mailing list
> [email protected]
> http://www.antlr.org/mailman/listinfo/antlr-dev
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 [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/il-antlr-interest?hl=en.
