[antlr-interest] Aggressive vs. Lazy Buffering in ANTLR

[Kay Roepke]

On 19. Dec 2006, at 16:59 , Foolish Ewe wrote:

> However, I tried making a simple input method that uses Lazy  
> buffering (i.e. reads characters
> on demand extending the buffer).  This lazy input stream no longer  
> blocks on the constructor,
> however, now I've noticed that the CommonTokenStream constructor  
> appears to block.

What do you do in your input stream's constructor? The  
CommonTokenStream constructors shouldn't block,
they just set the members.

> It appears to be blocking in fillBuffer, but I don't see an  
> explicit call in the constructor.

fillBuffer is invoked on the first call to LT. Maybe you're seeing  
that? Though it doesn't sound
likely based on what you described...

> The impact of this is that it negates the interactive support that  
> the lazy buffering of my
> home-grown input stream class, so I'd like to fix it.
>
> Is there a lazy buffering (buffer as input becomes available/on  
> demand) variant of TokenStream
> support or have I made some error?

No there's nothing like that in the standard distribution. Could you  
post some code?

cheers,

-k

-- 
Kay Röpke
http://classdump.org/