That was quite amusing, I read the &quot;Welcome to your new list&quot; message before the wikitech-l message. Anyway, a list just for parser discussion is good.<br><br>Here&#39;s a bit of ANTLR grammar I wrote to handle basic article structure: paragraph blocks and &quot;special blocks&quot;, where two consecutive blocks of the same type need an extra linefeed. Since I haven&#39;t written any Lex or Yacc before, I&#39;m still wrestling a bit with what are probably fairly basic problems. In this case, I found the requirement of an extra linefeed quite challenging to implement without ambiguity problems.
<br><br>As it is, this does work, but spews out a huge number of warnings and even an&nbsp;apparently non-fatal &quot;fatal error&quot;. I presume some of these problems can be avoided through semantic and syntactic predicates, if not backtracking, memoization (no, that&#39;s not a typo). Any ANTLR experts here?
<br><br>Steve<br><br>--<br>grammar paras;<br><br>article	:	pseries? (sseries (EOF| pseries))*;<br>	pseries	:	para (N+ para)* N*;<br>sseries	:	specialblock (N+ specialblock)* N*;	<br><br><br>specialblock<br>	:	(spaceblock|listblock)+;
<br><br>spaceblock<br>	:	spaceline+;<br><br>spaceline<br>	:	SPECIALCHAR char* N;<br><br>listblock<br>	:	(listitem)+;<br>	listitem:	(bulletitem | numberitem | indentitem | defitem);<br><br>bulletitem<br>	:	      BULLETCHAR (listitem | (nonlistchar char*)? N);
<br><br>numberitem<br>	:	      NUMBERCHAR (listitem | (nonlistchar char*)? N);<br><br>indentitem<br>	:	      INDENTCHAR (listitem | (nonlistchar char*)? N);<br><br>defitem<br>	:	      DEFCHAR (nonindentchar)* (definition | INDENTCHAR? N );
<br>	definition<br>	:	&#39;:&#39; char+ N;	<br><br>BULLETCHAR: 	&#39;*&#39;;<br>NUMBERCHAR:     &#39;#&#39;;<br>INDENTCHAR:	&#39;:&#39;;<br>DEFCHAR :	&#39;;&#39;;<br><br>para	:	(nonspecialchar char* N)+;<br><br>listchar:	 BULLETCHAR | NUMBERCHAR | INDENTCHAR | DEFCHAR;
<br><br>SPECIALCHAR<br>	:	&#39; &#39;;<br>nonlistchar<br>	:	SPECIALCHAR | nonspecialchar;<br>char	:	nonlistchar | listchar;	<br>		nonindentchar<br>	:	nonlistchar | BULLETCHAR | NUMBERCHAR | DEFCHAR;<br>	N	:	&#39;\r&#39;? &#39;\n&#39; 	;
<br><br>nowiki	:	 NOWIKI;<br>NOWIKI	:	&#39;&lt;nowiki&gt;&#39;( options {greedy=false;} : . )*&#39;&lt;/nowiki&gt;&#39;;<br><br>nonspecialchar<br>	:	NONSPECIALCHAR | nowiki;<br><br>NONSPECIALCHAR<br>	:	(&#39;A&#39;..&#39;Z&#39;| &#39;a&#39;..&#39;z&#39; | &#39;0&#39;..&#39;9&#39; | &#39;\&#39;&#39; | &#39;&quot;&#39; | &#39;(&#39; | &#39;)&#39;)+;
<br>--<br><br>PS you might notice the above grammar implements two &quot;improvements&quot; to the ;definition:term notation:<br><br>1. The ;definition has to be the last item in the list. &nbsp;Constructs like ##;## are worthless.
<br>2. A trailing : is treated literally.<br>