[antlr-interest] ANTLR2005 workshop proceedings / photos
Terence Parr
parrt at cs.usfca.edu
Tue Nov 1 18:02:58 PST 2005
On Nov 1, 2005, at 1:49 PM, shmuel siegel wrote:
> Terence Parr wrote:
>> Howdy,
>> For your enjoyment:
>> http://www.antlr.org/workshop/ANTLR2005/summary.html
>> Lots of great talks and fun was had by all! Thanks to all of the
>> attendees. :) Lots of great ideas floating around!
>> Terence
> I was reading the ANTLR-v3 powerpoint presentation. The following
> bullet
> caught my attention.
>
> "Does single token insertion or deletion if necessary to keep going"
>
> Does this imply that you transparently support the latest
> definition for
> ECMAScript virtual semicolons? I.e., if you reach a point that the
> parser cannot consume the next token, insert a virtual semicolon
> and try
> again.
The single token insertion works upon mismatched token; i.e., LA(1)!
=t. It asks if the current token LA(1) is actually something that
can start what could follow the missing token t. If so, it pretends
to insert t and continues the parse. In your case, if someone forgot
a semicolon:
a=b
c=d;
then it would say c does not equal semicolon, but c is in fact what
follows a semicolon; pretend to insert and continue. So, the upshot
is, that it might just work though you'd get a syntax error reported
at the missing semicolon.
Ter
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