[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
>I do like to use Java standard APIs as much as possible. Knowing that I
>needed a reader with "push back" capability, I thought that the
>PushbackReader reader was exactly what I was looking for. It turns out that
>the PushbackReader class uses a fixed size "pushback" buffer, and that this
>size must be passed to the constructor.
This may be a bit heretical, but have you considered abandoning
streams/readers entirely, and just using a single large String as the lexer
input? We're already building the entire parse tree in memory, which is
many times larger than the input file. And using a raw String will
probably be faster than reading a single character at a time from a stream.
(I recently wrote a simple file comparison utility in Java. At first, I
just compared the inputs one character at a time, using BufferedStreams and
all that. Slow as hell. I then implemented my own buffering on top of
BufferedStream, and got a speed-up of about 20x. My theory is that the
overhead of doing a method call for each character was causing the dreadful
>Normally, you should not be concerned with this problem. I will fix this in
>the next version of SableCC. I will then take a simple Reader as parameter
>to the Lexer constructor. I'll also implement an internal variable size
Fair enough. In the mean time, it's easy enough to crank up the buffer size.