Re: [jruby-user] What does nested repeat operator + and ? was replaced with '*' mean?

Hi,

It's a warning issued when Oniguruma finds nested quantifier within a 
quantifier (not an enclose) and the quantifies are not quantified by ranges:

if (!isByNumber() && !qnt.isByNumber() && 
env.syntax.warnReduntantNestedRepeat()) { ...

for example:

/(?:a+)?/ ( which is equivalent to: /(:?a)*/ )

then it does:

           QuantifierNode qnt = (QuantifierNode)target;
           int nestQNum = popularNum();
           int targetQNum = qnt.popularNum();

where popular number is a number assigned to different types of quantifiers:
from Oniguruma comment: ?:0, *:1, +:2, ??:3, *?:4, +?:5

so nested (+) is 2:
nesting (?) is 0:

then the following reduction table is used:

   enum ReduceType {
       ASIS,       /* as is */
       DEL,        /* delete parent */
       A,          /* to '*'    */
       AQ,         /* to '*?'   */
       QQ,         /* to '??'   */
       P_QQ,       /* to '+)??' */
       PQ_Q,       /* to '+?)?' */
   }

   final ReduceType[][]REDUCE_TABLE = {
     {DEL,     A,      A,      QQ,     AQ,     ASIS}, /* '?'  */
     {DEL,     DEL,    DEL,    P_QQ,   P_QQ,   DEL},  /* '*'  */
     {A,       A,      DEL,    ASIS,   P_QQ,   DEL},  /* '+'  */
     {DEL,     AQ,     AQ,     DEL,    AQ,     AQ},   /* '??' */
     {DEL,     DEL,    DEL,    DEL,    DEL,    DEL},  /* '*?' */
     {ASIS,    PQ_Q,   DEL,    AQ,     AQ,     DEL}   /* '+?' */    
   };

so: ReduceType[2, 0] == A (the asterisk)

the implementation for this case is:

       case A:
           setTarget(other.target); // steal the nested target's target
           // and set * characteristics
           lower = 0;
           upper = REPEAT_INFINITE;
           greedy = true;
           break;

The other thing is that 1.9 has this warning turned off by default 
(which we also should have, will fix that)

lopex



James Moore wrote:
> Tried to run the tests for my rails app using trunk jruby (r5081), and
> I'm getting these error messages:
>
> run test/unit/asterisk_call_file_test.rb
> /home/james/jruby/lib/ruby/gems/1.8/gems/actionpack-1.99.0.8178/lib/action_view/helpers/text_helper.rb:425
> warning:
>                         (                          # leading text
>                           <\w+.*?>|                # leading HTML tag, or
>                           [^=!:'"/]|               # leading punctuation, or
>                           ^                        # beginning of line
>                         )
>                         (
>                           (?:https?://)|           # protocol spec, or
>                           (?:www\.)                # www.*
>                         )
>                         (
>                           [-\w]+                   # subdomain or domain
>                           (?:\.[-\w]+)*            # remaining
> subdomains or domain
>                           (?::\d+)?                # port
>                           (?:/(?:(?:[~\w\+@%-]|(?:[,.;:][^\s$]))+)?)* # path
>                           (?:\?[\w\+@%&=.;-]+)?     # query string
>                           (?:\#[\w\-]*)?           # trailing anchor
>                         )
>                         ([[:punct:]]|\s|<|$)       # trailing text
>                         nested repeat operator + and ? was replaced with '*'
>
>
> I'm not sure what that error message means (and I'm definitely sure I
> don't want to understand that regex...).
>
>   


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