Wow. input.LT(1) or LT(-1) is returning null. I'd turn on -trace option of antlr then recompile and retry. that may say more T On Nov 30, 2010, at 12:59 PM, Bill Lear wrote:
> On Tuesday, November 30, 2010 at 11:25:18 (-0800) Terence Parr writes: >> >> On Nov 29, 2010, at 7:00 PM, Bill Lear wrote: >> >>> I've followed the sensible advice to create an island grammar to deal >>> with parsing an unstructured shell command along with more structured >>> input. Unfortunately, when I follow the examples as given in the >>> Antlr examples zip file, I get very close, but then either a NULL >>> pointer exception bites, or I can only parse one line of "island" >>> input --- I can't figure out how to return control back to the "sea" >>> parser and have it read more input. >> >> Can you tell us where it gets null ptr? > > Surely. Here you go: > > % cat input | java Command > Got shell. Going native. > Exception in thread "main" java.lang.NullPointerException > at org.antlr.runtime.Parser.getMissingSymbol(Parser.java:70) > at > org.antlr.runtime.BaseRecognizer.recoverFromMismatchedToken(BaseRecognizer.java:604) > at org.antlr.runtime.BaseRecognizer.match(BaseRecognizer.java:115) > at ShellParser.shell(ShellParser.java:48) > at CommandLexer.mSHELL(CommandLexer.java:57) > at CommandLexer.mTokens(CommandLexer.java:688) > at org.antlr.runtime.Lexer.nextToken(Lexer.java:84) > at > org.antlr.runtime.CommonTokenStream.fillBuffer(CommonTokenStream.java:95) > at org.antlr.runtime.CommonTokenStream.LT(CommonTokenStream.java:238) > at org.antlr.runtime.CommonTokenStream.LA(CommonTokenStream.java:300) > at CommandParser.commands(CommandParser.java:56) > at Command.main(Command.java:8) > > Let me know if I can do anything further to narrow it down for you. > > > Bill 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.
