[antlr-interest] Re: Semantic predicates that aren't & hoisting

[John D. Mitchell]

>>>>> "David" == David Jung <jungdl at ornl.gov> writes:
> John D. Mitchell said:
>>>>>>> "David" == David Jung <jungdl at ornl.gov> writes:
[...]

>>> expressionList : '{' expr ( ';' expr )* '}' ;

>>> The important rule for this discussion being expressionList.  So, a
>>> valid expr can be "5" or "{5; 7; 8}" or "{ { 2; 3; }; <-- notice this
>>> ';' 5; } "

>> Make the exprList rule a bit more complicated and have it explicitly
>> understand the recursive nesting of the exprLists.

> I'm not exactly sure how that would work.

Add the handling of the recursive exprList directly into exprList. E.g.:

exprList
	: '{' ( exprListOrStmt )* '}'
	;

exprListOrStmt
	: exprList
	| expr ';'
	;

> Note that a semi-colon following an expr that was an expressionList isn't
> the only case where I want it optional, but immediately after *any*
> expressionList (which could be nested down).  e.g.  another valid expr
> rule option is
[...]

Ah, the old separator vs. terminator argument.  Well, there are certainly
plenty of examples of that idea floating around. :-)

Since you seem to have some control over the language, I strongly suggest
implementing your grammar with semi-colons as terminators first and then go
back after you have that well debugged and tweak it to be a separator.

Hope this helps,
		John