[REBOL] Re: parse, again...
From: lmecir:mbox:vol:cz at: 6-Nov-2001 10:03
Hi Halvard,
Volker: << ...thread started like
parse "this that something some others"[some[thru "something"|thru end]]
...thread-starter ... wondered why 'parse said "not successfully parsed"...
>>
Halvard: <<Actually, I wasn't using "thru end" _intuitively_, although it
was among my
different approaches. But once I thought about it, I _do_ find it logic to
be able to do a parse "thru end", since 'end is indeed defined as a
something (even though simply a marker) after the last character in a
string. "To end" produces an infinite loop (guess this is a bug)...
I'd like just as much that "to end" would simply work...
>>
The problem is, that [to end] must work as it does to work correctly. See
this:
parse "" [to end to end] ; == true
I am sure, that this behaviour is correct regardless of the quantity of [to
end] you put in there. That is why any attempt to write
parse "" rule: [to end rule]
or
parse "" [any [to end]]
Correctly ends up in an infinite cycle, because PARSE is unable to finish
its work. It's up to the user to write a rule that really parses through
INPUT and doesn't try to pretend it's doing anything useful when it actually
isn't.
Cheers
Ladislav