Re: [jflex-users] ambiguities in JFLex syntax grammar from the manual

[Steve R. <sa...@od...>]

Hi Romildo,

José Romildo Malaquias wrote:
> On Mon, Apr 19, 2010 at 12:25:08PM -0400, Steve Rowe wrote:
> [...]
>>  > 2. In macro definitions, how does one know where one regular
>>  >    expression finishes?
>>
>> Within the macro section of a spec, newlines terminate regular 
>> expressions - from the above-linked LexScan.flex:
>>
>>    500 {NL} { if (macroDefinition) { yybegin(MACROS); }
>>               return symbol(REGEXPEND); }
> 
> Then there is an error in examples/java/java.flex in the distribution:
> 
>    /* comments */
>    Comment = {TraditionalComment} | {EndOfLineComment} | 
>              {DocumentationComment}
> 
> Here the macro definition is not supposed to be in a unique line.

I was wrong; starting at line 464 in LexScan.flex:

   464     {WSPNL}*"|"{WSP}*$      { if (macroDefinition) {
   465                               yybegin(EATWSPNL);
   466                               return symbol(BAR);
   467                             }

That is, when '|' occurs at end-of-line within a macro definition, the 
newline is ignored.

Steve